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Posted to commits@commons.apache.org by si...@apache.org on 2011/01/29 22:29:53 UTC
svn commit: r1065114 -
/commons/sandbox/digester3/trunk/src/main/java/org/apache/commons/digester3/FactoryCreateRule.java
Author: simonetripodi
Date: Sat Jan 29 21:29:53 2011
New Revision: 1065114
URL: http://svn.apache.org/viewvc?rev=1065114&view=rev
Log:
first checkin of ObjectCreationFactory class
Added:
commons/sandbox/digester3/trunk/src/main/java/org/apache/commons/digester3/FactoryCreateRule.java (with props)
Added: commons/sandbox/digester3/trunk/src/main/java/org/apache/commons/digester3/FactoryCreateRule.java
URL: http://svn.apache.org/viewvc/commons/sandbox/digester3/trunk/src/main/java/org/apache/commons/digester3/FactoryCreateRule.java?rev=1065114&view=auto
==============================================================================
--- commons/sandbox/digester3/trunk/src/main/java/org/apache/commons/digester3/FactoryCreateRule.java (added)
+++ commons/sandbox/digester3/trunk/src/main/java/org/apache/commons/digester3/FactoryCreateRule.java Sat Jan 29 21:29:53 2011
@@ -0,0 +1,224 @@
+/* $Id$
+ *
+ * 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.apache.commons.digester3;
+
+import java.util.Stack;
+
+import org.apache.commons.digester3.spi.ObjectCreationFactory;
+import org.xml.sax.Attributes;
+
+/**
+ * <p>Rule implementation that uses an {@link ObjectCreationFactory} to create
+ * a new object which it pushes onto the object stack. When the element is
+ * complete, the object will be popped.</p>
+ *
+ * <p>This rule is intended in situations where the element's attributes are
+ * needed before the object can be created. A common senario is for the
+ * ObjectCreationFactory implementation to use the attributes as parameters
+ * in a call to either a factory method or to a non-empty constructor.
+ */
+public class FactoryCreateRule extends Rule {
+
+ /** Should exceptions thrown by the factory be ignored? */
+ private boolean ignoreCreateExceptions;
+
+ /** Stock to manage */
+ private Stack<Boolean> exceptionIgnoredStack;
+
+ /**
+ * The attribute containing an override class name if it is present.
+ */
+ private String attributeName = null;
+
+ /**
+ * The Java class name of the ObjectCreationFactory to be created.
+ * This class must have a no-arguments constructor.
+ */
+ private String className = null;
+
+ /**
+ * The object creation factory we will use to instantiate objects
+ * as required based on the attributes specified in the matched XML
+ * element.
+ */
+ private ObjectCreationFactory<?> creationFactory = null;
+
+ /**
+ * Construct a factory create rule that will use the specified
+ * class name (possibly overridden by the specified attribute if present)
+ * to create an {@link ObjectCreationFactory}, which will then be used
+ * to instantiate an object instance and push it onto the stack.
+ *
+ * @param className Default Java class name of the factory class
+ * @param attributeName Attribute name which, if present, contains an
+ * override of the class name of the object creation factory to create.
+ * @param ignoreCreateExceptions if true, exceptions thrown by the object
+ * creation factory will be ignored.
+ */
+ public FactoryCreateRule(String className, String attributeName, boolean ignoreCreateExceptions) {
+ this.className = className;
+ this.attributeName = attributeName;
+ this.ignoreCreateExceptions = ignoreCreateExceptions;
+ }
+
+ /**
+ * Construct a factory create rule using the given, already instantiated,
+ * {@link ObjectCreationFactory}.
+ *
+ * @param creationFactory called on to create the object.
+ * @param ignoreCreateExceptions if true, exceptions thrown by the object
+ * creation factory will be ignored.
+ */
+ public <T> FactoryCreateRule(ObjectCreationFactory<T> creationFactory, boolean ignoreCreateExceptions) {
+ this.creationFactory = creationFactory;
+ this.ignoreCreateExceptions = ignoreCreateExceptions;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public void begin(String namespace, String name, Attributes attributes) throws Exception {
+ if (this.ignoreCreateExceptions) {
+ if (this.exceptionIgnoredStack == null) {
+ this.exceptionIgnoredStack = new Stack<Boolean>();
+ }
+
+ try {
+ Object instance = getFactory(attributes).createObject(attributes);
+
+ if (this.getDigester().getLog().isDebugEnabled()) {
+ this.getDigester().getLog().debug(String.format("[FactoryCreateRule]{%s} New %s",
+ this.getDigester().getMatch(),
+ (instance == null ? "null object" : instance.getClass().getName())));
+ }
+
+ this.getDigester().push(instance);
+ this.exceptionIgnoredStack.push(Boolean.FALSE);
+ } catch (Exception e) {
+ // log message and error
+ if (this.getDigester().getLog().isInfoEnabled()) {
+ this.getDigester().getLog().info("[FactoryCreateRule] Create exception ignored: "
+ + ((e.getMessage() == null) ? e.getClass().getName() : e.getMessage()));
+
+ if (this.getDigester().getLog().isDebugEnabled()) {
+ this.getDigester().getLog().debug("[FactoryCreateRule] Ignored exception:", e);
+ }
+ }
+ this.exceptionIgnoredStack.push(Boolean.TRUE);
+ }
+ } else {
+ Object instance = getFactory(attributes).createObject(attributes);
+
+ if (this.getDigester().getLog().isDebugEnabled()) {
+ this.getDigester().getLog().debug(String.format("[FactoryCreateRule]{%s} New %s",
+ this.getDigester().getMatch(),
+ (instance == null ? "null object" : instance.getClass().getName())));
+ }
+
+ this.getDigester().push(instance);
+ }
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public void end(String namespace, String name) throws Exception {
+ // check if object was created
+ // this only happens if an exception was thrown and we're ignoring them
+ if (this.ignoreCreateExceptions
+ && this.exceptionIgnoredStack != null
+ && !this.exceptionIgnoredStack.empty()) {
+
+ if (this.exceptionIgnoredStack.pop().booleanValue()) {
+ // creation exception was ignored
+ // nothing was put onto the stack
+ if (this.getDigester().getLog().isTraceEnabled()) {
+ this.getDigester().getLog().trace("[FactoryCreateRule] No creation so no push so no pop");
+ }
+ return;
+ }
+ }
+
+ Object top = this.getDigester().pop();
+ if (this.getDigester().getLog().isDebugEnabled()) {
+ this.getDigester().getLog().debug(String.format("[FactoryCreateRule]{%s} Pop %s",
+ this.getDigester().getMatch(),
+ top.getClass().getName()));
+ }
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ @Override
+ public void finish() throws Exception {
+ if (this.attributeName != null) {
+ this.creationFactory = null;
+ }
+ }
+
+ /**
+ * Render a printable version of this Rule.
+ */
+ @Override
+ public String toString() {
+ StringBuilder sb = new StringBuilder("FactoryCreateRule[")
+ .append("className=")
+ .append(this.className)
+ .append(", attributeName=")
+ .append(this.attributeName);
+ if (this.creationFactory != null) {
+ sb.append(", creationFactory=");
+ sb.append(this.creationFactory);
+ }
+ sb.append("]");
+ return (sb.toString());
+ }
+
+ /**
+ * Return an instance of our associated object creation factory,
+ * creating one if necessary.
+ *
+ * @param attributes Attributes passed to our factory creation element
+ *
+ * @exception Exception if any error occurs
+ */
+ protected ObjectCreationFactory<?> getFactory(Attributes attributes) throws Exception {
+ if (this.creationFactory == null) {
+ String realClassName = this.className;
+ if (this.attributeName != null) {
+ String value = attributes.getValue(this.attributeName);
+ if (value != null) {
+ realClassName = value;
+ }
+ }
+ if (this.getDigester().getLog().isDebugEnabled()) {
+ this.getDigester().getLog().debug(String.format("[FactoryCreateRule]{%s} New factory %s",
+ this.getDigester().getMatch(),
+ realClassName));
+ }
+ Class<?> clazz = this.getDigester().getClassLoader().loadClass(realClassName);
+ this.creationFactory = (ObjectCreationFactory<?>) clazz.newInstance();
+ this.creationFactory.setDigester(this.getDigester());
+ }
+ return this.creationFactory;
+ }
+
+}
Propchange: commons/sandbox/digester3/trunk/src/main/java/org/apache/commons/digester3/FactoryCreateRule.java
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