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Posted to commits@polygene.apache.org by ni...@apache.org on 2015/07/31 04:47:55 UTC

[36/51] [abbrv] [partial] zest-java git commit: Revert "First round of changes to move to org.apache.zest namespace."

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/property/InvalidPropertyTypeException.java
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diff --git a/core/api/src/main/java/org/qi4j/api/property/InvalidPropertyTypeException.java b/core/api/src/main/java/org/qi4j/api/property/InvalidPropertyTypeException.java
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--- /dev/null
+++ b/core/api/src/main/java/org/qi4j/api/property/InvalidPropertyTypeException.java
@@ -0,0 +1,40 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.qi4j.api.property;
+
+import java.lang.reflect.AccessibleObject;
+import org.qi4j.api.common.ConstructionException;
+
+/**
+ * Thrown when attempting to subclass Property.
+ */
+public class InvalidPropertyTypeException extends ConstructionException
+{
+    public InvalidPropertyTypeException( AccessibleObject accessor )
+    {
+        super( createMessage(accessor) );
+    }
+
+    private static String createMessage( AccessibleObject accessor )
+    {
+        StringBuilder builder = new StringBuilder();
+        builder.append( "Not allowed to subclass " + Property.class.getName() + ". Property accessor " + accessor + " is returning a Property subclass." );
+        return builder.toString();
+    }
+}

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/property/Numbers.java
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diff --git a/core/api/src/main/java/org/qi4j/api/property/Numbers.java b/core/api/src/main/java/org/qi4j/api/property/Numbers.java
new file mode 100644
index 0000000..00c0e5f
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+++ b/core/api/src/main/java/org/qi4j/api/property/Numbers.java
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+/*
+ * Copyright (c) 2009, Rickard Öberg. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.qi4j.api.property;
+
+import java.math.BigDecimal;
+
+/**
+ * Convenience class for mathematical operations on numerical properties.
+ * <pre>import static org.qi4j.api.property.Numbers.*;
+ * ...
+ * add( object.numberProperty(), 5 );</pre>
+ */
+public final class Numbers
+{
+    // Integer operations
+
+    public static Property<Integer> add( Property<Integer> property, int amount )
+    {
+        property.set( property.get() + amount );
+        return property;
+    }
+
+    public static Property<Integer> mult( Property<Integer> property, int amount )
+    {
+        property.set( property.get() * amount );
+        return property;
+    }
+
+    public static Property<Integer> sub( Property<Integer> property, int amount )
+    {
+        property.set( property.get() - amount );
+        return property;
+    }
+
+    public static Property<Integer> div( Property<Integer> property, int amount )
+    {
+        property.set( property.get() / amount );
+        return property;
+    }
+
+    // Long operations
+
+    public static Property<Long> add( Property<Long> property, long amount )
+    {
+        property.set( property.get() + amount );
+        return property;
+    }
+
+    public static Property<Long> mult( Property<Long> property, long amount )
+    {
+        property.set( property.get() * amount );
+        return property;
+    }
+
+    public static Property<Long> sub( Property<Long> property, long amount )
+    {
+        property.set( property.get() - amount );
+        return property;
+    }
+
+    public static Property<Long> div( Property<Long> property, long amount )
+    {
+        property.set( property.get() / amount );
+        return property;
+    }
+
+    // Double operations
+
+    public static Property<Double> add( Property<Double> property, double amount )
+    {
+        property.set( property.get() + amount );
+        return property;
+    }
+
+    public static Property<Double> mult( Property<Double> property, double amount )
+    {
+        property.set( property.get() * amount );
+        return property;
+    }
+
+    public static Property<Double> sub( Property<Double> property, double amount )
+    {
+        property.set( property.get() - amount );
+        return property;
+    }
+
+    public static Property<Double> div( Property<Double> property, double amount )
+    {
+        property.set( property.get() / amount );
+        return property;
+    }
+
+    // Float operations
+
+    public static Property<Float> add( Property<Float> property, float amount )
+    {
+        property.set( property.get() + amount );
+        return property;
+    }
+
+    public static Property<Float> mult( Property<Float> property, float amount )
+    {
+        property.set( property.get() * amount );
+        return property;
+    }
+
+    public static Property<Float> sub( Property<Float> property, float amount )
+    {
+        property.set( property.get() - amount );
+        return property;
+    }
+
+    public static Property<Float> div( Property<Float> property, float amount )
+    {
+        property.set( property.get() / amount );
+        return property;
+    }
+
+    // BigDecimal operations
+
+    public static Property<BigDecimal> add( Property<BigDecimal> property, BigDecimal amount )
+    {
+        property.set( property.get().add( amount ) );
+        return property;
+    }
+
+    public static Property<BigDecimal> mult( Property<BigDecimal> property, BigDecimal amount )
+    {
+        property.set( property.get().multiply( amount ) );
+        return property;
+    }
+
+    public static Property<BigDecimal> sub( Property<BigDecimal> property, BigDecimal amount )
+    {
+        property.set( property.get().subtract( amount ) );
+        return property;
+    }
+
+    public static Property<BigDecimal> div( Property<BigDecimal> property, BigDecimal amount )
+    {
+        property.set( property.get().divide( amount ) );
+        return property;
+    }
+}

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/property/Property.java
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diff --git a/core/api/src/main/java/org/qi4j/api/property/Property.java b/core/api/src/main/java/org/qi4j/api/property/Property.java
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+++ b/core/api/src/main/java/org/qi4j/api/property/Property.java
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+/*
+ * Copyright (c) 2007-2011, Rickard Öberg. All Rights Reserved.
+ *
+ * Licensed  under the  Apache License,  Version 2.0  (the "License");
+ * you may not use  this file  except in  compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed  under the  License is distributed on an "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.qi4j.api.property;
+
+/**
+ * Properties are declared in Composite interfaces by using this interface.
+ * <p>
+ * It creates a first-class object for the property from which you can get and set the value, and access any
+ * metadata about it.
+ * </p>
+ * <p>The type of the Property can be one of the following:</p>
+ * <ul>
+ * <li> A boxed primitive (Long,Integer,Boolean, etc.)</li>
+ * <li> String</li>
+ * <li> BigInteger</li>
+ * <li> BigDecimal</li>
+ * <li> Date</li>
+ * <li> DateTime (Joda Time)</li>
+ * <li> LocalDateTime (Joda Time)</li>
+ * <li> A serializable</li>
+ * <li> A ValueComposite</li>
+ * <li> A List, Set or Collection of any of the above</li>
+ * </ul>
+ *
+ * @param <T> Parameterized type of the Property
+ */
+public interface Property<T>
+{
+    /**
+     * Get the value of the property.
+     *
+     * @return the value
+     */
+    T get();
+
+    /**
+     * Set the value of the property
+     *
+     * @param newValue the new value
+     *
+     * @throws IllegalArgumentException if the value has an invalid value
+     * @throws IllegalStateException    if the property is immutable
+     */
+    void set( T newValue )
+        throws IllegalArgumentException, IllegalStateException;
+}

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/property/PropertyDescriptor.java
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diff --git a/core/api/src/main/java/org/qi4j/api/property/PropertyDescriptor.java b/core/api/src/main/java/org/qi4j/api/property/PropertyDescriptor.java
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+++ b/core/api/src/main/java/org/qi4j/api/property/PropertyDescriptor.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2007, Rickard Öberg. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.qi4j.api.property;
+
+import java.lang.reflect.AccessibleObject;
+import java.lang.reflect.Type;
+import org.qi4j.api.common.QualifiedName;
+import org.qi4j.api.structure.MetaInfoHolder;
+import org.qi4j.api.structure.Module;
+import org.qi4j.api.type.ValueType;
+
+/**
+ * Property Descriptor.
+ */
+public interface PropertyDescriptor extends MetaInfoHolder
+{
+    boolean isImmutable();
+
+    /**
+     * Get the qualified name of the property which is equal to:
+     * <pre><code>
+     * &lt;interface name&gt;:&lt;method name&gt;
+     * </code></pre>
+     *
+     * @return the qualified name of the property
+     */
+    QualifiedName qualifiedName();
+
+    /**
+     * Get the type of the property. If the property is declared
+     * as Property&lt;X&gt; then X is returned.
+     *
+     * @return the property type
+     */
+    Type type();
+
+    AccessibleObject accessor();
+
+    Object initialValue( Module module );
+
+    ValueType valueType();
+
+    boolean queryable();
+}

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/property/PropertyMixin.java
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diff --git a/core/api/src/main/java/org/qi4j/api/property/PropertyMixin.java b/core/api/src/main/java/org/qi4j/api/property/PropertyMixin.java
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+++ b/core/api/src/main/java/org/qi4j/api/property/PropertyMixin.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2007, Rickard Öberg. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.qi4j.api.property;
+
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+import org.qi4j.api.common.AppliesTo;
+import org.qi4j.api.common.AppliesToFilter;
+import org.qi4j.api.injection.scope.State;
+
+/**
+ * Generic mixin for properties.
+ */
+// START SNIPPET: actual
+@AppliesTo( { PropertyMixin.PropertyFilter.class } )
+public final class PropertyMixin
+    implements InvocationHandler
+{
+    @State
+    private StateHolder state;
+
+    @Override
+    public Object invoke( Object proxy, Method method, Object[] args )
+        throws Throwable
+    {
+        return state.propertyFor( method );
+    }
+
+    /**
+     * Filter Property methods to apply generic Property Mixin.
+     */
+    public static class PropertyFilter
+        implements AppliesToFilter
+    {
+        @Override
+        public boolean appliesTo( Method method, Class<?> mixin, Class<?> compositeType, Class<?> modifierClass )
+        {
+            return Property.class.isAssignableFrom( method.getReturnType() );
+        }
+    }
+}
+// END SNIPPET: actual

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/property/PropertyWrapper.java
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diff --git a/core/api/src/main/java/org/qi4j/api/property/PropertyWrapper.java b/core/api/src/main/java/org/qi4j/api/property/PropertyWrapper.java
new file mode 100644
index 0000000..dc2259d
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+++ b/core/api/src/main/java/org/qi4j/api/property/PropertyWrapper.java
@@ -0,0 +1,71 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.qi4j.api.property;
+
+/**
+ * If you want to catch getting and setting properties, then create a GenericConcern
+ * that wraps the Zest-supplied Property instance with PropertyWrappers. Override
+ * get() and/or set() to perform your custom code.
+ */
+public class PropertyWrapper
+    implements Property<Object>
+{
+    protected Property<Object> next;
+
+    public PropertyWrapper( Property<Object> next )
+    {
+        this.next = next;
+    }
+
+    public Property<Object> next()
+    {
+        return next;
+    }
+
+    @Override
+    public Object get()
+    {
+        return next.get();
+    }
+
+    @Override
+    public void set( Object newValue )
+        throws IllegalArgumentException, IllegalStateException
+    {
+        next.set( newValue );
+    }
+
+    @Override
+    public int hashCode()
+    {
+        return next.hashCode();
+    }
+
+    @Override
+    public boolean equals( Object obj )
+    {
+        return next.equals( obj );
+    }
+
+    @Override
+    public String toString()
+    {
+        return next.toString();
+    }
+}

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/property/StateHolder.java
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diff --git a/core/api/src/main/java/org/qi4j/api/property/StateHolder.java b/core/api/src/main/java/org/qi4j/api/property/StateHolder.java
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index 0000000..dfd0b29
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+++ b/core/api/src/main/java/org/qi4j/api/property/StateHolder.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2008, Rickard Öberg. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package org.qi4j.api.property;
+
+import java.lang.reflect.AccessibleObject;
+
+/**
+ * This represents the state of a composite (properties).
+ */
+public interface StateHolder
+{
+    /**
+     * Get a property for a specific accessor
+     *
+     * @param accessor of the property
+     *
+     * @return the property
+     *
+     * @throws IllegalArgumentException if no property for given accessor exists
+     */
+    <T> Property<T> propertyFor( AccessibleObject accessor )
+        throws IllegalArgumentException;
+
+    Iterable<? extends Property<?>> properties();
+}

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/property/package.html
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diff --git a/core/api/src/main/java/org/qi4j/api/property/package.html b/core/api/src/main/java/org/qi4j/api/property/package.html
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+++ b/core/api/src/main/java/org/qi4j/api/property/package.html
@@ -0,0 +1,21 @@
+<!--
+Licensed to the Apache Software Foundation (ASF) under one or more
+contributor license agreements.  See the NOTICE file distributed with
+this work for additional information regarding copyright ownership.
+The ASF licenses this file to You under the Apache License, Version 2.0
+(the "License"); you may not use this file except in compliance with
+the License.  You may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
+<html>
+    <body>
+        <h2>Property API.</h2>
+    </body>
+</html>

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/query/MissingIndexingSystemException.java
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diff --git a/core/api/src/main/java/org/qi4j/api/query/MissingIndexingSystemException.java b/core/api/src/main/java/org/qi4j/api/query/MissingIndexingSystemException.java
new file mode 100644
index 0000000..6bfd216
--- /dev/null
+++ b/core/api/src/main/java/org/qi4j/api/query/MissingIndexingSystemException.java
@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2008, Niclas Hedhman. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+package org.qi4j.api.query;
+
+/**
+ * This Exception is thrown in <code>QueryBuilderFactory.newQueryBuilder()</code> method if
+ * no indexing subsystem has been declared in the assembly.
+ */
+public final class MissingIndexingSystemException
+    extends QueryException
+{
+    private static final long serialVersionUID = 5147421865890379209L;
+
+    public MissingIndexingSystemException()
+    {
+        super( "No EntityFinder has been declared in the assembly of the application." );
+    }
+}

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/query/NotQueryableException.java
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diff --git a/core/api/src/main/java/org/qi4j/api/query/NotQueryableException.java b/core/api/src/main/java/org/qi4j/api/query/NotQueryableException.java
new file mode 100644
index 0000000..74737eb
--- /dev/null
+++ b/core/api/src/main/java/org/qi4j/api/query/NotQueryableException.java
@@ -0,0 +1,88 @@
+/*
+ * Copyright 2009 Alin Dreghiciu.
+ *
+ * Licensed  under the  Apache License,  Version 2.0  (the "License");
+ * you may not use  this file  except in  compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed  under the  License is distributed on an "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.qi4j.api.query;
+
+import java.lang.reflect.AccessibleObject;
+import java.lang.reflect.Member;
+import org.qi4j.api.entity.Queryable;
+import org.qi4j.api.property.GenericPropertyInfo;
+import org.qi4j.api.util.Classes;
+
+/**
+ * Thrown in case that a non queryable type or accessor (marked with @Queriable(false)) is used during query building,
+ * or when non-Property, non-Associations are trying to be queried (possibly can not happen).
+ */
+public class NotQueryableException
+    extends QueryException
+{
+    private static final long serialVersionUID = 1L;
+
+    /**
+     * Constructor.
+     *
+     * @param message exception message
+     */
+    public NotQueryableException( final String message )
+    {
+        super( message );
+    }
+
+    /**
+     * Verify that the provided accessor method has not been marked with a Queryable(false).
+     *
+     * @param accessor accessor method
+     *
+     * @throws NotQueryableException - If accessor method has been marked as not queryable
+     */
+    public static void throwIfNotQueryable( final AccessibleObject accessor )
+    {
+        Queryable queryable = accessor.getAnnotation( Queryable.class );
+        if( queryable != null && !queryable.value() )
+        {
+            throw new NotQueryableException(
+                String.format(
+                    "%1$s \"%2$s\" (%3$s) is not queryable as has been marked with @Queryable(false)",
+                    Classes.RAW_CLASS.map( GenericPropertyInfo.propertyTypeOf( accessor ) ).getSimpleName(),
+                    ( (Member) accessor ).getName(),
+                    ( (Member) accessor ).getDeclaringClass().getName()
+                )
+            );
+        }
+    }
+
+    /**
+     * Verify that the provided type has not been marked with a Queryable(false).
+     *
+     * @param type a type
+     *
+     * @throws NotQueryableException - If type has been marked as not queryable
+     */
+    public static void throwIfNotQueryable( final Class<?> type )
+    {
+        Queryable queryable = type.getAnnotation( Queryable.class );
+        if( queryable != null && !queryable.value() )
+        {
+            throw new NotQueryableException(
+                String.format(
+                    "Type \"%1$s\" is not queryable as has been marked with @Queryable(false)",
+                    type.getName()
+                )
+            );
+        }
+    }
+}
\ No newline at end of file

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/query/Query.java
----------------------------------------------------------------------
diff --git a/core/api/src/main/java/org/qi4j/api/query/Query.java b/core/api/src/main/java/org/qi4j/api/query/Query.java
new file mode 100644
index 0000000..504b2e2
--- /dev/null
+++ b/core/api/src/main/java/org/qi4j/api/query/Query.java
@@ -0,0 +1,138 @@
+/*
+ * Copyright 2007 Rickard Öberg.
+ * Copyright 2007 Niclas Hedhman.
+ * Copyright 2008 Alin Dreghiciu.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+package org.qi4j.api.query;
+
+import java.io.Serializable;
+import org.qi4j.api.property.Property;
+import org.qi4j.api.query.grammar.OrderBy;
+
+/**
+ * This represents a Query in an indexing system. It is created from a
+ * {@link QueryBuilder}, which decides the "where" clause in the query.
+ * <p>
+ * Additional limitations, such as paging, ordering, and variables, can be set on
+ * a Query before it is executed by calling one of find(), iterator(),
+ * or count().
+ * </p>
+ * <p>
+ * DDD tip: typically Queries are created in the Domain Model and passed to the UI,
+ * which sets the order and paging before executing it.
+ * </p>
+ */
+public interface Query<T>
+    extends Iterable<T>, Serializable
+{
+    /**
+     * Set the ordering rules. If many segments are used for ordering
+     * then they will be applied in order.
+     *
+     * @param segments the segments to order by
+     *
+     * @return the Query
+     */
+    Query<T> orderBy( OrderBy... segments );
+
+    /**
+     * Append an ordering rule to the existing segments.
+     *
+     * @param property the property to order by
+     * @param order the order to apply
+     *
+     * @return the Query
+     */
+    Query<T> orderBy( final Property<?> property, final OrderBy.Order order );
+
+    /**
+     * Append an ascending ordering rule to the existing segments.
+     *
+     * @param property the property to order by
+     *
+     * @return the Query
+     */
+    Query<T> orderBy( Property<?> property );
+
+    /**
+     * Set the index of the first result. Default is 0 (zero).
+     *
+     * @param firstResult which index to use as the first one
+     *
+     * @return the Query
+     */
+    Query<T> firstResult( int firstResult );
+
+    /**
+     * Set how many results should be returned. Default is that
+     * there is no limit set.
+     *
+     * @param maxResults that shouldbe returned
+     *
+     * @return the query
+     */
+    Query<T> maxResults( int maxResults );
+
+    /**
+     * Get the first Entity that matches the criteria. This
+     * executes the Query.
+     *
+     * @return the first found Entity or null if none were found
+     *
+     * @throws QueryExecutionException if the query fails
+     */
+    T find()
+        throws QueryExecutionException;
+
+    /**
+     * Set the value of a named variable.
+     *
+     * @param name  of the variable
+     * @param value of the variable
+     *
+     * @return the query
+     */
+    Query<T> setVariable( String name, Object value );
+
+    /**
+     * Get the value of a named variable.
+     *
+     * @param name of the variable
+     *
+     * @return value of the variable
+     */
+    <V> V getVariable( String name );
+
+    /**
+     * Get the result type of this Query
+     *
+     * @return the result type
+     */
+    Class<T> resultType();
+
+    /**
+     * Count how many results would be returned by this Query.
+     * This executes the Query.
+     *
+     * @return result count
+     *
+     * @throws QueryExecutionException if the query fails
+     */
+    long count()
+        throws QueryExecutionException;
+}
\ No newline at end of file

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/query/QueryBuilder.java
----------------------------------------------------------------------
diff --git a/core/api/src/main/java/org/qi4j/api/query/QueryBuilder.java b/core/api/src/main/java/org/qi4j/api/query/QueryBuilder.java
new file mode 100644
index 0000000..c07552c
--- /dev/null
+++ b/core/api/src/main/java/org/qi4j/api/query/QueryBuilder.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2007 Rickard Öberg.
+ * Copyright 2008 Alin Dreghiciu.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+package org.qi4j.api.query;
+
+import org.qi4j.api.composite.Composite;
+import org.qi4j.functional.Specification;
+
+/**
+ * QueryBuilders are used to create {@link Query} instances.
+ * Iteratively add where() clauses to the query, and then use
+ * {@link org.qi4j.api.unitofwork.UnitOfWork#newQuery(QueryBuilder)}  to instantiate the Query.
+ * QueryBuilders are immutable, so when adding new where-clauses you get new instances. This
+ *
+ * DDD tip: Query objects are not executed immediately, so they
+ * should be constructed in the domain model and handed over to
+ * the UI, which can then further constrain it before actual
+ * execution.
+ */
+public interface QueryBuilder<T>
+{
+    /**
+     * Add a where-clause to the Query. Use {@link QueryExpressions}
+     * to create the expression.
+     *
+     * @param specification the where clause
+     *
+     * @return a new builder with the added where-clause
+     */
+    QueryBuilder<T> where( Specification<Composite> specification );
+
+    /**
+     * Create a new query with the declared where-clauses that will be evaluated against the iterable entries.
+     *
+     * @param iterable collection of objects (composites?)
+     *
+     * @return a new Query instance
+     */
+    Query<T> newQuery( Iterable<T> iterable );
+}
\ No newline at end of file

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/query/QueryBuilderFactory.java
----------------------------------------------------------------------
diff --git a/core/api/src/main/java/org/qi4j/api/query/QueryBuilderFactory.java b/core/api/src/main/java/org/qi4j/api/query/QueryBuilderFactory.java
new file mode 100644
index 0000000..8841030
--- /dev/null
+++ b/core/api/src/main/java/org/qi4j/api/query/QueryBuilderFactory.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright 2007 Niclas Hedhman.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *  
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied.
+ * 
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.qi4j.api.query;
+
+/**
+ * This is used to create QueryBuilders.
+ *
+ * @see QueryBuilder
+ */
+public interface QueryBuilderFactory
+{
+    /**
+     * Create a new QueryBuilder.
+     *
+     * @param resultType the type of the result that you want
+     *
+     * @return a QueryBuilder
+     *
+     * @throws MissingIndexingSystemException if there is no EntityFinder service available
+     */
+    <T> QueryBuilder<T> newQueryBuilder( Class<T> resultType )
+        throws MissingIndexingSystemException;
+}
\ No newline at end of file

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/query/QueryException.java
----------------------------------------------------------------------
diff --git a/core/api/src/main/java/org/qi4j/api/query/QueryException.java b/core/api/src/main/java/org/qi4j/api/query/QueryException.java
new file mode 100644
index 0000000..6caca4c
--- /dev/null
+++ b/core/api/src/main/java/org/qi4j/api/query/QueryException.java
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2008, Niclas Hedhman. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+package org.qi4j.api.query;
+
+/**
+ * Base class for Query exceptions.
+ */
+public abstract class QueryException
+    extends RuntimeException
+{
+    private static final long serialVersionUID = -3602596752342902060L;
+
+    public QueryException()
+    {
+    }
+
+    public QueryException( final String message )
+    {
+        super( message );
+    }
+
+    public QueryException( final String message, final Throwable cause )
+    {
+        super( message, cause );
+    }
+}

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/query/QueryExecutionException.java
----------------------------------------------------------------------
diff --git a/core/api/src/main/java/org/qi4j/api/query/QueryExecutionException.java b/core/api/src/main/java/org/qi4j/api/query/QueryExecutionException.java
new file mode 100644
index 0000000..f8cad23
--- /dev/null
+++ b/core/api/src/main/java/org/qi4j/api/query/QueryExecutionException.java
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2008, Rickard Öberg. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+package org.qi4j.api.query;
+
+/**
+ * Throw this exception if a query could not be executed
+ */
+public final class QueryExecutionException
+    extends QueryException
+{
+    private static final long serialVersionUID = 5147421865890379209L;
+
+    public QueryExecutionException( String message )
+    {
+        super( message );
+    }
+
+    public QueryExecutionException( String message, Throwable cause )
+    {
+        super( message, cause );
+    }
+}
\ No newline at end of file

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/query/QueryExpressionException.java
----------------------------------------------------------------------
diff --git a/core/api/src/main/java/org/qi4j/api/query/QueryExpressionException.java b/core/api/src/main/java/org/qi4j/api/query/QueryExpressionException.java
new file mode 100644
index 0000000..f0a7f8e
--- /dev/null
+++ b/core/api/src/main/java/org/qi4j/api/query/QueryExpressionException.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2009 Niclas Hedhman.
+ *
+ * Licensed  under the  Apache License,  Version 2.0  (the "License");
+ * you may not use  this file  except in  compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed  under the  License is distributed on an "AS IS" BASIS,
+ * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
+ * implied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.qi4j.api.query;
+
+/**
+ * Throw this exception if a QueryExpression is invalid.
+ */
+public class QueryExpressionException
+    extends QueryException
+{
+
+    private static final long serialVersionUID = 1L;
+
+    public QueryExpressionException( String message )
+    {
+        super( message );
+    }
+
+}

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/query/QueryExpressions.java
----------------------------------------------------------------------
diff --git a/core/api/src/main/java/org/qi4j/api/query/QueryExpressions.java b/core/api/src/main/java/org/qi4j/api/query/QueryExpressions.java
new file mode 100644
index 0000000..45501ee
--- /dev/null
+++ b/core/api/src/main/java/org/qi4j/api/query/QueryExpressions.java
@@ -0,0 +1,944 @@
+/*
+ * Copyright 2007-2011 Rickard Öberg.
+ * Copyright 2007-2010 Niclas Hedhman.
+ * Copyright 2008 Alin Dreghiciu.
+ * Copyright 2012 Stanislav Muhametsin.
+ * Copyright 2012-2014 Paul Merlin.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * ied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.qi4j.api.query;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+import java.lang.reflect.Type;
+import java.util.Arrays;
+import java.util.Collection;
+import org.qi4j.api.association.Association;
+import org.qi4j.api.association.GenericAssociationInfo;
+import org.qi4j.api.association.ManyAssociation;
+import org.qi4j.api.association.NamedAssociation;
+import org.qi4j.api.composite.Composite;
+import org.qi4j.api.entity.Identity;
+import org.qi4j.api.injection.scope.State;
+import org.qi4j.api.property.GenericPropertyInfo;
+import org.qi4j.api.property.Property;
+import org.qi4j.api.query.grammar.AndSpecification;
+import org.qi4j.api.query.grammar.AssociationFunction;
+import org.qi4j.api.query.grammar.AssociationNotNullSpecification;
+import org.qi4j.api.query.grammar.AssociationNullSpecification;
+import org.qi4j.api.query.grammar.ContainsAllSpecification;
+import org.qi4j.api.query.grammar.ContainsSpecification;
+import org.qi4j.api.query.grammar.EqSpecification;
+import org.qi4j.api.query.grammar.GeSpecification;
+import org.qi4j.api.query.grammar.GtSpecification;
+import org.qi4j.api.query.grammar.LeSpecification;
+import org.qi4j.api.query.grammar.LtSpecification;
+import org.qi4j.api.query.grammar.ManyAssociationContainsSpecification;
+import org.qi4j.api.query.grammar.ManyAssociationFunction;
+import org.qi4j.api.query.grammar.MatchesSpecification;
+import org.qi4j.api.query.grammar.NamedAssociationContainsNameSpecification;
+import org.qi4j.api.query.grammar.NamedAssociationContainsSpecification;
+import org.qi4j.api.query.grammar.NamedAssociationFunction;
+import org.qi4j.api.query.grammar.NeSpecification;
+import org.qi4j.api.query.grammar.NotSpecification;
+import org.qi4j.api.query.grammar.OrSpecification;
+import org.qi4j.api.query.grammar.OrderBy;
+import org.qi4j.api.query.grammar.PropertyFunction;
+import org.qi4j.api.query.grammar.PropertyNotNullSpecification;
+import org.qi4j.api.query.grammar.PropertyNullSpecification;
+import org.qi4j.api.query.grammar.PropertyReference;
+import org.qi4j.api.query.grammar.Variable;
+import org.qi4j.api.util.NullArgumentException;
+import org.qi4j.functional.Specification;
+
+import static org.qi4j.functional.Iterables.first;
+import static org.qi4j.functional.Iterables.prepend;
+
+/**
+ * Static factory methods for query expressions and operators.
+ */
+public final class QueryExpressions
+{
+    // This is used for eq(Association,Composite)
+    private static final Method IDENTITY_METHOD;
+
+    static
+    {
+        try
+        {
+            IDENTITY_METHOD = Identity.class.getMethod( "identity" );
+        }
+        catch( NoSuchMethodException e )
+        {
+            throw new InternalError( "Zest Core API codebase is corrupted. Contact Zest team: QueryExpressions" );
+        }
+    }
+
+    // Templates and variables -----------------------------------------------|
+
+    /**
+     * Create a Query Template using the given type.
+     *
+     * @param <T> the type of the template
+     * @param clazz a class declaring the type of the template
+     *
+     * @return a new Query Template
+     */
+    public static <T> T templateFor( Class<T> clazz )
+    {
+        NullArgumentException.validateNotNull( "Template class", clazz );
+
+        if( clazz.isInterface() )
+        {
+            return clazz.cast( Proxy.newProxyInstance( clazz.getClassLoader(),
+                                                       array( clazz ),
+                                                       new TemplateHandler<T>( null, null, null, null ) ) );
+        }
+        else
+        {
+            try
+            {
+                T mixin = clazz.newInstance();
+                for( Field field : clazz.getFields() )
+                {
+                    if( field.getAnnotation( State.class ) != null )
+                    {
+                        if( field.getType().equals( Property.class ) )
+                        {
+                            field.set( mixin,
+                                       Proxy.newProxyInstance( field.getType().getClassLoader(),
+                                                               array( field.getType() ),
+                                                               new PropertyReferenceHandler<>( new PropertyFunction<T>( null, null, null, null, field ) ) ) );
+                        }
+                        else if( field.getType().equals( Association.class ) )
+                        {
+                            field.set( mixin,
+                                       Proxy.newProxyInstance( field.getType().getClassLoader(),
+                                                               array( field.getType() ),
+                                                               new AssociationReferenceHandler<>( new AssociationFunction<T>( null, null, null, field ) ) ) );
+                        }
+                        else if( field.getType().equals( ManyAssociation.class ) )
+                        {
+                            field.set( mixin,
+                                       Proxy.newProxyInstance( field.getType().getClassLoader(),
+                                                               array( field.getType() ),
+                                                               new ManyAssociationReferenceHandler<>( new ManyAssociationFunction<T>( null, null, null, field ) ) ) );
+                        }
+                        else if( field.getType().equals( NamedAssociation.class ) )
+                        {
+                            field.set( mixin,
+                                       Proxy.newProxyInstance( field.getType().getClassLoader(),
+                                                               array( field.getType() ),
+                                                               new NamedAssociationReferenceHandler<>( new NamedAssociationFunction<T>( null, null, null, field ) ) ) );
+                        }
+                    }
+                }
+                return mixin;
+            }
+            catch( IllegalAccessException | IllegalArgumentException | InstantiationException | SecurityException e )
+            {
+                throw new IllegalArgumentException( "Cannot use class as template", e );
+            }
+        }
+    }
+
+    /**
+     * Create a Query Template using the given mixin class and association.
+     *
+     * @param <T> the type of the template
+     * @param mixinType  a class declaring the type of the template
+     * @param association an association
+     *
+     * @return a new Query Template
+     */
+    public static <T> T templateFor( final Class<T> mixinType, Association<?> association )
+    {
+        NullArgumentException.validateNotNull( "Mixin class", mixinType );
+        NullArgumentException.validateNotNull( "Association", association );
+        return mixinType.cast( Proxy.newProxyInstance( mixinType.getClassLoader(),
+                                                       array( mixinType ),
+                                                       new TemplateHandler<T>( null,
+                                                                               association( association ),
+                                                                               null,
+                                                                               null ) ) );
+    }
+
+    public static <T> T oneOf( final ManyAssociation<T> association )
+    {
+        NullArgumentException.validateNotNull( "Association", association );
+        return association.get( 0 );
+    }
+
+    public static <T> T oneOf( final NamedAssociation<T> association )
+    {
+        NullArgumentException.validateNotNull( "Association", association );
+        return association.get( first( association ) );
+    }
+
+    /**
+     * Create a new Query Variable.
+     *
+     * @param name a name for the Variable
+     *
+     * @return a new Query Variable.
+     */
+    public static Variable variable( String name )
+    {
+        NullArgumentException.validateNotNull( "Variable name", name );
+        return new Variable( name );
+    }
+
+    /**
+     * Create a new Query Template PropertyFunction.
+     *
+     * @param <T> type of the Property
+     * @param property a Property
+     *
+     * @return a new Query Template PropertyFunction
+     */
+    @SuppressWarnings( "unchecked" )
+    public static <T> PropertyFunction<T> property( Property<T> property )
+    {
+        return ( (PropertyReferenceHandler<T>) Proxy.getInvocationHandler( property ) ).property();
+    }
+
+    /**
+     * Create a new Query Property instance.
+     *
+     * @param <T> type of the Property
+     * @param mixinClass mixin of the Property
+     * @param fieldName name of the Property field
+     *
+     * @return a new Query Property instance for the given mixin and property name.
+     */
+    @SuppressWarnings( "unchecked" )
+    public static <T> Property<T> property( Class<?> mixinClass, String fieldName )
+    {
+        try
+        {
+            Field field = mixinClass.getField( fieldName );
+            if( !Property.class.isAssignableFrom( field.getType() ) )
+            {
+                throw new IllegalArgumentException( "Field must be of type Property<?>" );
+            }
+            return (Property<T>) Proxy.newProxyInstance(
+                mixinClass.getClassLoader(),
+                array( field.getType() ),
+                new PropertyReferenceHandler<>( new PropertyFunction<T>( null, null, null, null, field ) ) );
+        }
+        catch( NoSuchFieldException e )
+        {
+            throw new IllegalArgumentException( "No such field '" + fieldName + "' in mixin " + mixinClass.getName() );
+        }
+    }
+
+    /**
+     * Create a new Query Template AssociationFunction.
+     *
+     * @param <T> type of the Association
+     * @param association an Association
+     *
+     * @return a new Query Template AssociationFunction
+     */
+    @SuppressWarnings( "unchecked" )
+    public static <T> AssociationFunction<T> association( Association<T> association )
+    {
+        return ( (AssociationReferenceHandler<T>) Proxy.getInvocationHandler( association ) ).association();
+    }
+
+    /**
+     * Create a new Query Template ManyAssociationFunction.
+     *
+     * @param <T> type of the ManyAssociation
+     * @param association a ManyAssociation
+     *
+     * @return a new Query Template ManyAssociationFunction
+     */
+    @SuppressWarnings( "unchecked" )
+    public static <T> ManyAssociationFunction<T> manyAssociation( ManyAssociation<T> association )
+    {
+        return ( (ManyAssociationReferenceHandler<T>) Proxy.getInvocationHandler( association ) ).manyAssociation();
+    }
+
+    /**
+     * Create a new Query Template NamedAssociationFunction.
+     *
+     * @param <T> type of the NamedAssociation
+     * @param association a NamedAssociation
+     *
+     * @return a new Query Template NamedAssociationFunction
+     */
+    @SuppressWarnings( "unchecked" )
+    public static <T> NamedAssociationFunction<T> namedAssociation( NamedAssociation<T> association )
+    {
+        return ( (NamedAssociationReferenceHandler<T>) Proxy.getInvocationHandler( association ) ).namedAssociation();
+    }
+
+    // And/Or/Not ------------------------------------------------------------|
+    /**
+     * Create a new AND specification.
+     *
+     * @param left first operand
+     * @param right second operand
+     * @param optionalRight optional operands
+     *
+     * @return a new AND specification
+     */
+    @SafeVarargs
+    public static AndSpecification and( Specification<Composite> left,
+                                        Specification<Composite> right,
+                                        Specification<Composite>... optionalRight
+    )
+    {
+        return new AndSpecification( prepend( left, prepend( right, Arrays.asList( optionalRight ) ) ) );
+    }
+
+    /**
+     * Create a new OR specification.
+     *
+     * @param specs operands
+     *
+     * @return a new OR specification
+     */
+    @SafeVarargs
+    public static OrSpecification or( Specification<Composite>... specs )
+    {
+        return new OrSpecification( Arrays.asList( specs ) );
+    }
+
+    /**
+     * Create a new NOT specification.
+     *
+     * @param operand specification to be negated
+     *
+     * @return a new NOT specification
+     */
+    public static NotSpecification not( Specification<Composite> operand )
+    {
+        return new NotSpecification( operand );
+    }
+
+    // Comparisons -----------------------------------------------------------|
+
+    /**
+     * Create a new EQUALS specification for a Property.
+     *
+     * @param property a Property
+     * @param value its value
+     *
+     * @return a new EQUALS specification for a Property.
+     */
+    public static <T> EqSpecification<T> eq( Property<T> property, T value )
+    {
+        return new EqSpecification<>( property( property ), value );
+    }
+
+    /**
+     * Create a new EQUALS specification for a Property using a named Variable.
+     *
+     * @param property a Property
+     * @param variable a Query Variable
+     *
+     * @return a new EQUALS specification for a Property using a named Variable.
+     */
+    @SuppressWarnings( {"raw", "unchecked"} )
+    public static <T> EqSpecification<T> eq( Property<T> property, Variable variable )
+    {
+        return new EqSpecification( property( property ), variable );
+    }
+
+    /**
+     * Create a new EQUALS specification for an Association.
+     *
+     * @param association an Association
+     * @param value its value
+     *
+     * @return a new EQUALS specification for an Association.
+     */
+    public static <T> EqSpecification<String> eq( Association<T> association, T value )
+    {
+        return new EqSpecification<>( new PropertyFunction<String>( null,
+                                                                    association( association ),
+                                                                    null,
+                                                                    null,
+                                                                    IDENTITY_METHOD ),
+                                      value.toString() );
+    }
+
+    /**
+     * Create a new GREATER OR EQUALS specification for a Property.
+     *
+     * @param property a Property
+     * @param value its value
+     *
+     * @return a new GREATER OR EQUALS specification for a Property.
+     */
+    public static <T> GeSpecification<T> ge( Property<T> property, T value )
+    {
+        return new GeSpecification<>( property( property ), value );
+    }
+
+    /**
+     * Create a new GREATER OR EQUALS specification for a Property using a named Variable.
+     *
+     * @param property a Property
+     * @param variable a Query Variable
+     *
+     * @return a new GREATER OR EQUALS specification for a Property using a named Variable.
+     */
+    @SuppressWarnings( {"raw", "unchecked"} )
+    public static <T> GeSpecification<T> ge( Property<T> property, Variable variable )
+    {
+        return new GeSpecification( property( property ), variable );
+    }
+
+    /**
+     * Create a new GREATER THAN specification for a Property.
+     *
+     * @param property a Property
+     * @param value its value
+     *
+     * @return a new GREATER THAN specification for a Property.
+     */
+    public static <T> GtSpecification<T> gt( Property<T> property, T value )
+    {
+        return new GtSpecification<>( property( property ), value );
+    }
+
+    /**
+     * Create a new GREATER THAN specification for a Property using a named Variable.
+     *
+     * @param property a Property
+     * @param variable a Query Variable
+     *
+     * @return a new GREATER THAN specification for a Property using a named Variable.
+     */
+    @SuppressWarnings( {"raw", "unchecked"} )
+    public static <T> GtSpecification<T> gt( Property<T> property, Variable variable )
+    {
+        return new GtSpecification( property( property ), variable );
+    }
+
+    /**
+     * Create a new LESS OR EQUALS specification for a Property.
+     *
+     * @param property a Property
+     * @param value its value
+     *
+     * @return a new LESS OR EQUALS specification for a Property.
+     */
+    public static <T> LeSpecification<T> le( Property<T> property, T value )
+    {
+        return new LeSpecification<>( property( property ), value );
+    }
+
+    /**
+     * Create a new LESS OR EQUALS specification for a Property using a named Variable.
+     *
+     * @param property a Property
+     * @param variable a Query Variable
+     *
+     * @return a new LESS OR EQUALS specification for a Property using a named Variable.
+     */
+    @SuppressWarnings( {"raw", "unchecked"} )
+    public static <T> LeSpecification<T> le( Property<T> property, Variable variable )
+    {
+        return new LeSpecification( property( property ), variable );
+    }
+
+    /**
+     * Create a new LESSER THAN specification for a Property.
+     *
+     * @param property a Property
+     * @param value its value
+     *
+     * @return a new LESSER THAN specification for a Property.
+     */
+    public static <T> LtSpecification<T> lt( Property<T> property, T value )
+    {
+        return new LtSpecification<>( property( property ), value );
+    }
+
+    /**
+     * Create a new LESSER THAN specification for a Property using a named Variable.
+     *
+     * @param property a Property
+     * @param variable a Query Variable
+     *
+     * @return a new LESSER THAN specification for a Property using a named Variable.
+     */
+    @SuppressWarnings( {"raw", "unchecked"} )
+    public static <T> LtSpecification<T> lt( Property<T> property, Variable variable )
+    {
+        return new LtSpecification( property( property ), variable );
+    }
+
+    /**
+     * Create a new NOT EQUALS specification for a Property.
+     *
+     * @param property a Property
+     * @param value its value
+     *
+     * @return a new NOT EQUALS specification for a Property.
+     */
+    public static <T> NeSpecification<T> ne( Property<T> property, T value )
+    {
+        return new NeSpecification<>( property( property ), value );
+    }
+
+    /**
+     * Create a new NOT EQUALS specification for a Property using a named Variable.
+     *
+     * @param property a Property
+     * @param variable a Query Variable
+     *
+     * @return a new NOT EQUALS specification for a Property using a named Variable.
+     */
+    @SuppressWarnings( {"raw", "unchecked"} )
+    public static <T> NeSpecification<T> ne( Property<T> property, Variable variable )
+    {
+        return new NeSpecification( property( property ), variable );
+    }
+
+    /**
+     * Create a new REGULAR EXPRESSION specification for a Property.
+     *
+     * @param property a Property
+     * @param regexp its value
+     *
+     * @return a new REGULAR EXPRESSION specification for a Property.
+     */
+    public static MatchesSpecification matches( Property<String> property, String regexp )
+    {
+        return new MatchesSpecification( property( property ), regexp );
+    }
+
+    /**
+     * Create a new REGULAR EXPRESSION specification for a Property using a named Variable.
+     *
+     * @param property a Property
+     * @param variable a Query Variable
+     *
+     * @return a new REGULAR EXPRESSION specification for a Property using a named Variable.
+     */
+    public static MatchesSpecification matches( Property<String> property, Variable variable )
+    {
+        return new MatchesSpecification( property( property ), variable );
+    }
+
+    // Null checks -----------------------------------------------------------|
+
+    /**
+     * Create a new NOT NULL specification for a Property.
+     *
+     * @param property a Property
+     *
+     * @return a new NOT NULL specification for a Property.
+     */
+    public static <T> PropertyNotNullSpecification<T> isNotNull( Property<T> property )
+    {
+        return new PropertyNotNullSpecification<>( property( property ) );
+    }
+
+    /**
+     * Create a new NULL specification for a Property.
+     *
+     * @param property a Property
+     *
+     * @return a new NULL specification for a Property.
+     */
+    public static <T> PropertyNullSpecification<T> isNull( Property<T> property )
+    {
+        return new PropertyNullSpecification<>( property( property ) );
+    }
+
+    /**
+     * Create a new NOT NULL specification for an Association.
+     *
+     * @param association an Association
+     *
+     * @return a new NOT NULL specification for an Association.
+     */
+    public static <T> AssociationNotNullSpecification<T> isNotNull( Association<T> association )
+    {
+        return new AssociationNotNullSpecification<>( association( association ) );
+    }
+
+    /**
+     * Create a new NULL specification for an Association.
+     *
+     * @param association an Association
+     *
+     * @return a new NULL specification for an Association.
+     */
+    public static <T> AssociationNullSpecification<T> isNull( Association<T> association )
+    {
+        return new AssociationNullSpecification<>( association( association ) );
+    }
+
+    // Collections -----------------------------------------------------------|
+
+    /**
+     * Create a new CONTAINS ALL specification for a Collection Property.
+     *
+     * @param collectionProperty a Collection Property
+     * @param values its values
+     *
+     * @return a new CONTAINS ALL specification for a Collection Property.
+     */
+    public static <T> ContainsAllSpecification<T> containsAll( Property<? extends Collection<T>> collectionProperty,
+                                                               Iterable<T> values )
+    {
+        NullArgumentException.validateNotNull( "Values", values );
+        return new ContainsAllSpecification<>( property( collectionProperty ), values );
+    }
+
+    /**
+     * Create a new CONTAINS ALL specification for a Collection Property using named Variables.
+     *
+     * @param collectionProperty a Collection Property
+     * @param variables named Variables
+     *
+     * @return a new CONTAINS ALL specification for a Collection Property using named Variables.
+     */
+    @SuppressWarnings( {"raw", "unchecked"} )
+    public static <T> ContainsAllSpecification<T> containsAllVariables(
+        Property<? extends Collection<T>> collectionProperty,
+        Iterable<Variable> variables )
+    {
+        NullArgumentException.validateNotNull( "Variables", variables );
+        return new ContainsAllSpecification( property( collectionProperty ), variables );
+    }
+
+    /**
+     * Create a new CONTAINS specification for a Collection Property.
+     *
+     * @param collectionProperty a Collection Property
+     * @param value the value
+     *
+     * @return a new CONTAINS specification for a Collection Property.
+     */
+    public static <T> ContainsSpecification<T> contains( Property<? extends Collection<T>> collectionProperty,
+                                                         T value )
+    {
+        NullArgumentException.validateNotNull( "Value", value );
+        return new ContainsSpecification<>( property( collectionProperty ), value );
+    }
+
+    /**
+     * Create a new CONTAINS specification for a Collection Property using named Variables.
+     *
+     * @param collectionProperty a Collection Property
+     * @param variable named Variable
+     *
+     * @return a new CONTAINS specification for a Collection Property using named Variables.
+     */
+    @SuppressWarnings( {"raw", "unchecked"} )
+    public static <T> ContainsSpecification<T> contains( Property<? extends Collection<T>> collectionProperty,
+                                                         Variable variable )
+    {
+        NullArgumentException.validateNotNull( "Variable", variable );
+        return new ContainsSpecification( property( collectionProperty ), variable );
+    }
+
+    /**
+     * Create a new CONTAINS specification for a ManyAssociation.
+     *
+     * @param manyAssoc  a ManyAssociation
+     * @param value the value
+     *
+     * @return a new CONTAINS specification for a ManyAssociation.
+     */
+    public static <T> ManyAssociationContainsSpecification<T> contains( ManyAssociation<T> manyAssoc, T value )
+    {
+        return new ManyAssociationContainsSpecification<>( manyAssociation( manyAssoc ), value );
+    }
+
+    /**
+     * Create a new CONTAINS specification for a NamedAssociation.
+     *
+     * @param namedAssoc  a NamedAssociation
+     * @param value the value
+     *
+     * @return a new CONTAINS specification for a NamedAssociation.
+     */
+    public static <T> NamedAssociationContainsSpecification<T> contains( NamedAssociation<T> namedAssoc, T value )
+    {
+        return new NamedAssociationContainsSpecification<>( namedAssociation( namedAssoc ), value );
+    }
+
+    /**
+     * Create a new CONTAINS NAME specification for a NamedAssociation.
+     *
+     * @param namedAssoc  a NamedAssociation
+     * @param name the name
+     *
+     * @return a new CONTAINS NAME specification for a NamedAssociation.
+     */
+    public static <T> NamedAssociationContainsNameSpecification<T> containsName( NamedAssociation<T> namedAssoc,
+                                                                                 String name )
+    {
+        return new NamedAssociationContainsNameSpecification<>( namedAssociation( namedAssoc ), name );
+    }
+
+    // Ordering --------------------------------------------------------------|
+    /**
+     * Create a new Query ascending order segment for a Property.
+     *
+     * @param <T> type of the Property
+     * @param property a Property
+     *
+     * @return a new Query ascending order segment for a Property.
+     */
+    public static <T> OrderBy orderBy( final Property<T> property )
+    {
+        return orderBy( property, OrderBy.Order.ASCENDING );
+    }
+
+    /**
+     * Create a new Query ordering segment for a Property.
+     *
+     * @param <T> type of the Property
+     * @param property a Property
+     * @param order ascending or descending
+     *
+     * @return a new Query ordering segment for a Property.
+     */
+    public static <T> OrderBy orderBy( final Property<T> property, final OrderBy.Order order )
+    {
+        return new OrderBy( property( property ), order );
+    }
+
+    // Query Templates InvocationHandlers ------------------------------------|
+
+    private static class TemplateHandler<T>
+        implements InvocationHandler
+    {
+        private final PropertyFunction<?> compositeProperty;
+        private final AssociationFunction<?> compositeAssociation;
+        private final ManyAssociationFunction<?> compositeManyAssociation;
+        private final NamedAssociationFunction<?> compositeNamedAssociation;
+
+        private TemplateHandler( PropertyFunction<?> compositeProperty,
+                                 AssociationFunction<?> compositeAssociation,
+                                 ManyAssociationFunction<?> compositeManyAssociation,
+                                 NamedAssociationFunction<?> compositeNamedAssociation
+        )
+        {
+            this.compositeProperty = compositeProperty;
+            this.compositeAssociation = compositeAssociation;
+            this.compositeManyAssociation = compositeManyAssociation;
+            this.compositeNamedAssociation = compositeNamedAssociation;
+        }
+
+        @Override
+        public Object invoke( Object o, Method method, Object[] objects )
+            throws Throwable
+        {
+            if( Property.class.isAssignableFrom( method.getReturnType() ) )
+            {
+                return Proxy.newProxyInstance(
+                    method.getReturnType().getClassLoader(),
+                    array( method.getReturnType() ),
+                    new PropertyReferenceHandler<>( new PropertyFunction<T>( compositeProperty,
+                                                                             compositeAssociation,
+                                                                             compositeManyAssociation,
+                                                                             compositeNamedAssociation,
+                                                                             method ) ) );
+            }
+            else if( Association.class.isAssignableFrom( method.getReturnType() ) )
+            {
+                return Proxy.newProxyInstance(
+                    method.getReturnType().getClassLoader(),
+                    array( method.getReturnType() ),
+                    new AssociationReferenceHandler<>( new AssociationFunction<T>( compositeAssociation,
+                                                                                   compositeManyAssociation,
+                                                                                   compositeNamedAssociation,
+                                                                                   method ) ) );
+            }
+            else if( ManyAssociation.class.isAssignableFrom( method.getReturnType() ) )
+            {
+                return Proxy.newProxyInstance(
+                    method.getReturnType().getClassLoader(),
+                    array( method.getReturnType() ),
+                    new ManyAssociationReferenceHandler<>( new ManyAssociationFunction<T>( compositeAssociation,
+                                                                                           compositeManyAssociation,
+                                                                                           compositeNamedAssociation,
+                                                                                           method ) ) );
+            }
+            else if( NamedAssociation.class.isAssignableFrom( method.getReturnType() ) )
+            {
+                return Proxy.newProxyInstance(
+                    method.getReturnType().getClassLoader(),
+                    array( method.getReturnType() ),
+                    new NamedAssociationReferenceHandler<>( new NamedAssociationFunction<T>( compositeAssociation,
+                                                                                             compositeManyAssociation,
+                                                                                             compositeNamedAssociation,
+                                                                                             method ) ) );
+            }
+
+            return null;
+        }
+    }
+
+    private static class PropertyReferenceHandler<T>
+        implements InvocationHandler
+    {
+        private final PropertyFunction<T> property;
+
+        private PropertyReferenceHandler( PropertyFunction<T> property )
+        {
+            this.property = property;
+        }
+
+        private PropertyFunction<T> property()
+        {
+            return property;
+        }
+
+        @Override
+        public Object invoke( Object o, final Method method, Object[] objects )
+            throws Throwable
+        {
+            if( method.equals( Property.class.getMethod( "get" ) ) )
+            {
+                Type propertyType = GenericPropertyInfo.propertyTypeOf( property.accessor() );
+                if( propertyType.getClass().equals( Class.class ) )
+                {
+                    return Proxy.newProxyInstance( method.getDeclaringClass().getClassLoader(),
+                                                   array( (Class<?>) propertyType, PropertyReference.class ),
+                                                   new TemplateHandler<T>( property, null, null, null ) );
+                }
+            }
+
+            return null;
+        }
+    }
+
+    private static class AssociationReferenceHandler<T>
+        implements InvocationHandler
+    {
+        private final AssociationFunction<T> association;
+
+        private AssociationReferenceHandler( AssociationFunction<T> association )
+        {
+            this.association = association;
+        }
+
+        private AssociationFunction<T> association()
+        {
+            return association;
+        }
+
+        @Override
+        public Object invoke( Object o, final Method method, Object[] objects )
+            throws Throwable
+        {
+            if( method.equals( Association.class.getMethod( "get" ) ) )
+            {
+                Type associationType = GenericAssociationInfo.associationTypeOf( association.accessor() );
+                if( associationType.getClass().equals( Class.class ) )
+                {
+                    return Proxy.newProxyInstance( method.getDeclaringClass().getClassLoader(),
+                                                   array( (Class) associationType, PropertyReference.class ),
+                                                   new TemplateHandler<T>( null, association, null, null ) );
+                }
+            }
+
+            return null;
+        }
+    }
+
+    private static class ManyAssociationReferenceHandler<T>
+        implements InvocationHandler
+    {
+        private final ManyAssociationFunction<T> manyAssociation;
+
+        private ManyAssociationReferenceHandler( ManyAssociationFunction<T> manyAssociation )
+        {
+            this.manyAssociation = manyAssociation;
+        }
+
+        public ManyAssociationFunction<T> manyAssociation()
+        {
+            return manyAssociation;
+        }
+
+        @Override
+        public Object invoke( Object o, final Method method, Object[] objects )
+            throws Throwable
+        {
+            if( method.equals( ManyAssociation.class.getMethod( "get", Integer.TYPE ) ) )
+            {
+                Type manyAssociationType = GenericAssociationInfo.associationTypeOf( manyAssociation.accessor() );
+                if( manyAssociationType.getClass().equals( Class.class ) )
+                {
+                    return Proxy.newProxyInstance( method.getDeclaringClass().getClassLoader(),
+                                                   array( (Class) manyAssociationType, PropertyReference.class ),
+                                                   new TemplateHandler<T>( null, null, manyAssociation, null ) );
+                }
+            }
+
+            return null;
+        }
+    }
+
+    private static class NamedAssociationReferenceHandler<T>
+        implements InvocationHandler
+    {
+        private final NamedAssociationFunction<T> namedAssociation;
+
+        private NamedAssociationReferenceHandler( NamedAssociationFunction<T> namedAssociation )
+        {
+            this.namedAssociation = namedAssociation;
+        }
+
+        public NamedAssociationFunction<T> namedAssociation()
+        {
+            return namedAssociation;
+        }
+
+        @Override
+        public Object invoke( Object o, final Method method, Object[] objects )
+            throws Throwable
+        {
+            if( method.equals( NamedAssociation.class.getMethod( "get", String.class ) ) )
+            {
+                Type namedAssociationType = GenericAssociationInfo.associationTypeOf( namedAssociation.accessor() );
+                if( namedAssociationType.getClass().equals( Class.class ) )
+                {
+                    return Proxy.newProxyInstance( method.getDeclaringClass().getClassLoader(),
+                                                   array( (Class) namedAssociationType, PropertyReference.class ),
+                                                   new TemplateHandler<T>( null, null, null, namedAssociation ) );
+                }
+            }
+
+            return null;
+        }
+    }
+
+    @SafeVarargs
+    private static <T> T[] array( T... array )
+    {
+        return array;
+    }
+
+    private QueryExpressions()
+    {
+    }
+}

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/query/grammar/AndSpecification.java
----------------------------------------------------------------------
diff --git a/core/api/src/main/java/org/qi4j/api/query/grammar/AndSpecification.java b/core/api/src/main/java/org/qi4j/api/query/grammar/AndSpecification.java
new file mode 100644
index 0000000..138ad00
--- /dev/null
+++ b/core/api/src/main/java/org/qi4j/api/query/grammar/AndSpecification.java
@@ -0,0 +1,56 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.qi4j.api.query.grammar;
+
+import org.qi4j.api.composite.Composite;
+import org.qi4j.functional.Specification;
+import org.qi4j.functional.Specifications;
+
+/**
+ * AND Specification.
+ */
+public class AndSpecification
+    extends BinarySpecification
+{
+
+    public AndSpecification( Iterable<Specification<Composite>> operands )
+    {
+        super( operands );
+    }
+
+    @Override
+    public boolean satisfiedBy( Composite item )
+    {
+        return Specifications.and( operands ).satisfiedBy( item );
+    }
+
+    @Override
+    public String toString()
+    {
+        StringBuilder sb = new StringBuilder( "(" );
+        String and = "";
+        for( Specification<Composite> operand : operands )
+        {
+            sb.append( and ).append( operand );
+            and = " and ";
+        }
+        return sb.append( ")" ).toString();
+    }
+
+}

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/query/grammar/AssociationFunction.java
----------------------------------------------------------------------
diff --git a/core/api/src/main/java/org/qi4j/api/query/grammar/AssociationFunction.java b/core/api/src/main/java/org/qi4j/api/query/grammar/AssociationFunction.java
new file mode 100644
index 0000000..ee423a0
--- /dev/null
+++ b/core/api/src/main/java/org/qi4j/api/query/grammar/AssociationFunction.java
@@ -0,0 +1,148 @@
+/*
+ * Copyright 2007-2011 Rickard Öberg.
+ * Copyright 2007-2010 Niclas Hedhman.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * ied.
+ *
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.qi4j.api.query.grammar;
+
+import java.lang.reflect.AccessibleObject;
+import java.lang.reflect.Member;
+import java.lang.reflect.Proxy;
+import java.lang.reflect.Type;
+import org.qi4j.api.association.Association;
+import org.qi4j.api.association.AssociationStateHolder;
+import org.qi4j.api.association.GenericAssociationInfo;
+import org.qi4j.api.association.ManyAssociation;
+import org.qi4j.api.association.NamedAssociation;
+import org.qi4j.api.composite.Composite;
+import org.qi4j.api.composite.CompositeInstance;
+import org.qi4j.api.query.QueryExpressionException;
+import org.qi4j.api.util.Classes;
+import org.qi4j.functional.Function;
+
+import static org.qi4j.api.util.Classes.typeOf;
+
+/**
+ * Function to get Entity Associations
+ */
+public class AssociationFunction<T>
+    implements Function<Composite, Association<T>>
+{
+    private final AssociationFunction<?> traversedAssociation;
+    private final ManyAssociationFunction<?> traversedManyAssociation;
+    private final NamedAssociationFunction<?> traversedNamedAssociation;
+    private final AccessibleObject accessor;
+
+    public AssociationFunction( AssociationFunction<?> traversedAssociation,
+                                ManyAssociationFunction<?> traversedManyAssociation,
+                                NamedAssociationFunction<?> traversedNamedAssociation,
+                                AccessibleObject accessor
+    )
+    {
+        this.traversedAssociation = traversedAssociation;
+        this.traversedManyAssociation = traversedManyAssociation;
+        this.traversedNamedAssociation = traversedNamedAssociation;
+        this.accessor = accessor;
+
+        Type returnType = typeOf( accessor );
+        if( !Association.class.isAssignableFrom( Classes.RAW_CLASS.map( returnType ) )
+            && !ManyAssociation.class.isAssignableFrom( Classes.RAW_CLASS.map( returnType ) )
+            && !NamedAssociation.class.isAssignableFrom( Classes.RAW_CLASS.map( returnType ) ) )
+        {
+            throw new QueryExpressionException( "Unsupported association type:" + returnType );
+        }
+        Type associationTypeAsType = GenericAssociationInfo.toAssociationType( returnType );
+        if( !( associationTypeAsType instanceof Class ) )
+        {
+            throw new QueryExpressionException( "Unsupported association type:" + associationTypeAsType );
+        }
+    }
+
+    public AssociationFunction<?> traversedAssociation()
+    {
+        return traversedAssociation;
+    }
+
+    public ManyAssociationFunction<?> traversedManyAssociation()
+    {
+        return traversedManyAssociation;
+    }
+
+    public NamedAssociationFunction<?> traversedNamedAssociation()
+    {
+        return traversedNamedAssociation;
+    }
+
+    public AccessibleObject accessor()
+    {
+        return accessor;
+    }
+
+    @Override
+    public Association<T> map( Composite entity )
+    {
+        try
+        {
+            Object target = entity;
+            if( traversedAssociation != null )
+            {
+                Association<?> association = traversedAssociation.map( entity );
+                if( association == null )
+                {
+                    return null;
+                }
+                target = association.get();
+            }
+            else if( traversedManyAssociation != null )
+            {
+                throw new IllegalArgumentException( "Cannot evaluate a ManyAssociation" );
+            }
+            else if( traversedNamedAssociation != null )
+            {
+                throw new IllegalArgumentException( "Cannot evaluate a NamedAssociation" );
+            }
+
+            if( target == null )
+            {
+                return null;
+            }
+
+            CompositeInstance handler = (CompositeInstance) Proxy.getInvocationHandler( target );
+            return ( (AssociationStateHolder) handler.state() ).associationFor( accessor );
+        }
+        catch( IllegalArgumentException e )
+        {
+            throw e;
+        }
+        catch( Throwable e )
+        {
+            throw new IllegalArgumentException( e );
+        }
+    }
+
+    @Override
+    public String toString()
+    {
+        if( traversedAssociation != null )
+        {
+            return traversedAssociation.toString() + "." + ( (Member) accessor ).getName();
+        }
+        else
+        {
+            return ( (Member) accessor ).getName();
+        }
+    }
+}

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/query/grammar/AssociationNotNullSpecification.java
----------------------------------------------------------------------
diff --git a/core/api/src/main/java/org/qi4j/api/query/grammar/AssociationNotNullSpecification.java b/core/api/src/main/java/org/qi4j/api/query/grammar/AssociationNotNullSpecification.java
new file mode 100644
index 0000000..64d6def
--- /dev/null
+++ b/core/api/src/main/java/org/qi4j/api/query/grammar/AssociationNotNullSpecification.java
@@ -0,0 +1,67 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.qi4j.api.query.grammar;
+
+import org.qi4j.api.association.Association;
+import org.qi4j.api.composite.Composite;
+
+/**
+ * Association not null Specification.
+ */
+public class AssociationNotNullSpecification<T>
+    extends ExpressionSpecification
+{
+    private AssociationFunction<T> association;
+
+    public AssociationNotNullSpecification( AssociationFunction<T> association )
+    {
+        this.association = association;
+    }
+
+    public AssociationFunction<T> association()
+    {
+        return association;
+    }
+
+    @Override
+    public boolean satisfiedBy( Composite item )
+    {
+        try
+        {
+            Association<T> assoc = association.map( item );
+
+            if( assoc == null )
+            {
+                return false;
+            }
+
+            return assoc.get() != null;
+        }
+        catch( IllegalArgumentException e )
+        {
+            return false;
+        }
+    }
+
+    @Override
+    public String toString()
+    {
+        return association.toString() + "is not null";
+    }
+}

http://git-wip-us.apache.org/repos/asf/zest-java/blob/a789141d/core/api/src/main/java/org/qi4j/api/query/grammar/AssociationNullSpecification.java
----------------------------------------------------------------------
diff --git a/core/api/src/main/java/org/qi4j/api/query/grammar/AssociationNullSpecification.java b/core/api/src/main/java/org/qi4j/api/query/grammar/AssociationNullSpecification.java
new file mode 100644
index 0000000..9f06b98
--- /dev/null
+++ b/core/api/src/main/java/org/qi4j/api/query/grammar/AssociationNullSpecification.java
@@ -0,0 +1,67 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.qi4j.api.query.grammar;
+
+import org.qi4j.api.association.Association;
+import org.qi4j.api.composite.Composite;
+
+/**
+ * Association null Specification.
+ */
+public class AssociationNullSpecification<T>
+    extends ExpressionSpecification
+{
+    private AssociationFunction<T> association;
+
+    public AssociationNullSpecification( AssociationFunction<T> association )
+    {
+        this.association = association;
+    }
+
+    public AssociationFunction<T> association()
+    {
+        return association;
+    }
+
+    @Override
+    public boolean satisfiedBy( Composite item )
+    {
+        try
+        {
+            Association<T> assoc = association.map( item );
+
+            if( assoc == null )
+            {
+                return true;
+            }
+
+            return assoc.get() == null;
+        }
+        catch( IllegalArgumentException e )
+        {
+            return true;
+        }
+    }
+
+    @Override
+    public String toString()
+    {
+        return association.toString() + "is null";
+    }
+}