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Posted to commits@xalan.apache.org by mk...@apache.org on 2005/05/17 19:24:26 UTC
cvs commit: xml-xalan/java/src/org/apache/xpath/jaxp JAXPExtensionsProvider.java JAXPPrefixResolver.java JAXPVariableStack.java XPathExpressionImpl.java XPathFactoryImpl.java XPathImpl.java
mkwan 2005/05/17 10:24:26
Added: java/src/org/apache/xpath/jaxp JAXPExtensionsProvider.java
JAXPPrefixResolver.java JAXPVariableStack.java
XPathExpressionImpl.java XPathFactoryImpl.java
XPathImpl.java
Log:
JAXP 1.3 integration
Commit the XPath API implementation under org.apache.xpath.jaxp
Revision Changes Path
1.1 xml-xalan/java/src/org/apache/xpath/jaxp/JAXPExtensionsProvider.java
Index: JAXPExtensionsProvider.java
===================================================================
/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* 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.
*/
// $Id: JAXPExtensionsProvider.java,v 1.1 2005/05/17 17:24:26 mkwan Exp $
package org.apache.xpath.jaxp;
import javax.xml.transform.TransformerException;
import javax.xml.xpath.XPathFunctionResolver;
import javax.xml.xpath.XPathFunction;
import javax.xml.xpath.XPathFunctionException;
import org.apache.xpath.ExtensionsProvider;
import org.apache.xpath.XPathContext;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.objects.XNodeSet;
import org.apache.xpath.res.XPATHErrorResources;
import org.apache.xalan.res.XSLMessages;
import org.apache.xpath.functions.FuncExtFunction;
import java.util.Vector;
import java.util.ArrayList;
import javax.xml.namespace.QName;
/**
*
* @author Ramesh Mandava ( ramesh.mandava@sun.com )
*/
public class JAXPExtensionsProvider implements ExtensionsProvider {
private final XPathFunctionResolver resolver;
private boolean extensionInvocationDisabled = false;
public JAXPExtensionsProvider(XPathFunctionResolver resolver) {
this.resolver = resolver;
this.extensionInvocationDisabled = false;
}
public JAXPExtensionsProvider(XPathFunctionResolver resolver,
boolean featureSecureProcessing ) {
this.resolver = resolver;
this.extensionInvocationDisabled = featureSecureProcessing;
}
/**
* Is the extension function available?
*/
public boolean functionAvailable(String ns, String funcName)
throws javax.xml.transform.TransformerException {
try {
if ( funcName == null ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_ARG_CANNOT_BE_NULL,
new Object[] {"Function Name"} );
throw new NullPointerException ( fmsg );
}
//Find the XPathFunction corresponding to namespace and funcName
javax.xml.namespace.QName myQName = new QName( ns, funcName );
javax.xml.xpath.XPathFunction xpathFunction =
resolver.resolveFunction ( myQName, 0 );
if ( xpathFunction == null ) {
return false;
}
return true;
} catch ( Exception e ) {
return false;
}
}
/**
* Is the extension element available?
*/
public boolean elementAvailable(String ns, String elemName)
throws javax.xml.transform.TransformerException {
return false;
}
/**
* Execute the extension function.
*/
public Object extFunction(String ns, String funcName, Vector argVec,
Object methodKey) throws javax.xml.transform.TransformerException {
try {
if ( funcName == null ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_ARG_CANNOT_BE_NULL,
new Object[] {"Function Name"} );
throw new NullPointerException ( fmsg );
}
//Find the XPathFunction corresponding to namespace and funcName
javax.xml.namespace.QName myQName = new QName( ns, funcName );
// JAXP 1.3 spec says When XMLConstants.FEATURE_SECURE_PROCESSING
// feature is set then invocation of extension functions need to
// throw XPathFunctionException
if ( extensionInvocationDisabled ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_EXTENSION_FUNCTION_CANNOT_BE_INVOKED,
new Object[] { myQName.toString() } );
throw new XPathFunctionException ( fmsg );
}
// Assuming user is passing all the needed parameters ( including
// default values )
int arity = argVec.size();
javax.xml.xpath.XPathFunction xpathFunction =
resolver.resolveFunction ( myQName, arity );
// not using methodKey
ArrayList argList = new ArrayList( arity);
for ( int i=0; i<arity; i++ ) {
Object argument = argVec.elementAt( i );
// XNodeSet object() returns NodeVector and not NodeList
// Explicitly getting NodeList by using nodelist()
if ( argument instanceof XNodeSet ) {
argList.add ( i, ((XNodeSet)argument).nodelist() );
} else if ( argument instanceof XObject ) {
Object passedArgument = ((XObject)argument).object();
argList.add ( i, passedArgument );
} else {
argList.add ( i, argument );
}
}
return ( xpathFunction.evaluate ( argList ));
} catch ( XPathFunctionException xfe ) {
// If we get XPathFunctionException then we want to terminate
// further execution by throwing WrappedRuntimeException
throw new org.apache.xml.utils.WrappedRuntimeException ( xfe );
} catch ( Exception e ) {
throw new javax.xml.transform.TransformerException ( e );
}
}
/**
* Execute the extension function.
*/
public Object extFunction(FuncExtFunction extFunction,
Vector argVec)
throws javax.xml.transform.TransformerException {
try {
String namespace = extFunction.getNamespace();
String functionName = extFunction.getFunctionName();
int arity = extFunction.getArgCount();
javax.xml.namespace.QName myQName =
new javax.xml.namespace.QName( namespace, functionName );
// JAXP 1.3 spec says When XMLConstants.FEATURE_SECURE_PROCESSING
// feature is set then invocation of extension functions need to
// throw XPathFunctionException
if ( extensionInvocationDisabled ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_EXTENSION_FUNCTION_CANNOT_BE_INVOKED, new Object[] { myQName.toString() } );
throw new XPathFunctionException ( fmsg );
}
XPathFunction xpathFunction =
resolver.resolveFunction( myQName, arity );
ArrayList argList = new ArrayList( arity);
for ( int i=0; i<arity; i++ ) {
Object argument = argVec.elementAt( i );
// XNodeSet object() returns NodeVector and not NodeList
// Explicitly getting NodeList by using nodelist()
if ( argument instanceof XNodeSet ) {
argList.add ( i, ((XNodeSet)argument).nodelist() );
} else if ( argument instanceof XObject ) {
Object passedArgument = ((XObject)argument).object();
argList.add ( i, passedArgument );
} else {
argList.add ( i, argument );
}
}
return ( xpathFunction.evaluate ( argList ));
} catch ( XPathFunctionException xfe ) {
// If we get XPathFunctionException then we want to terminate
// further execution by throwing WrappedRuntimeException
throw new org.apache.xml.utils.WrappedRuntimeException ( xfe );
} catch ( Exception e ) {
throw new javax.xml.transform.TransformerException ( e );
}
}
}
1.1 xml-xalan/java/src/org/apache/xpath/jaxp/JAXPPrefixResolver.java
Index: JAXPPrefixResolver.java
===================================================================
/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* 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.
*/
// $Id: JAXPPrefixResolver.java,v 1.1 2005/05/17 17:24:26 mkwan Exp $
package org.apache.xpath.jaxp;
import org.w3c.dom.Node;
import org.w3c.dom.NamedNodeMap;
import org.apache.xml.utils.PrefixResolver;
import javax.xml.namespace.NamespaceContext;
/**
* <meta name="usage" content="general"/>
* This class implements a Default PrefixResolver which
* can be used to perform prefix-to-namespace lookup
* for the XPath object.
* This class delegates the resolution to the passed NamespaceContext
*/
public class JAXPPrefixResolver implements PrefixResolver
{
private NamespaceContext namespaceContext;
public JAXPPrefixResolver ( NamespaceContext nsContext ) {
this.namespaceContext = nsContext;
}
public String getNamespaceForPrefix( String prefix ) {
return namespaceContext.getNamespaceURI( prefix );
}
/**
* Return the base identifier.
*
* @return null
*/
public String getBaseIdentifier() {
return null;
}
/**
* @see PrefixResolver#handlesNullPrefixes()
*/
public boolean handlesNullPrefixes() {
return false;
}
/**
* The URI for the XML namespace.
* (Duplicate of that found in org.apache.xpath.XPathContext).
*/
public static final String S_XMLNAMESPACEURI =
"http://www.w3.org/XML/1998/namespace";
/**
* Given a prefix and a Context Node, get the corresponding namespace.
* Warning: This will not work correctly if namespaceContext
* is an attribute node.
* @param prefix Prefix to resolve.
* @param namespaceContext Node from which to start searching for a
* xmlns attribute that binds a prefix to a namespace.
* @return Namespace that prefix resolves to, or null if prefix
* is not bound.
*/
public String getNamespaceForPrefix(String prefix,
org.w3c.dom.Node namespaceContext) {
Node parent = namespaceContext;
String namespace = null;
if (prefix.equals("xml")) {
namespace = S_XMLNAMESPACEURI;
} else {
int type;
while ((null != parent) && (null == namespace)
&& (((type = parent.getNodeType()) == Node.ELEMENT_NODE)
|| (type == Node.ENTITY_REFERENCE_NODE))) {
if (type == Node.ELEMENT_NODE) {
NamedNodeMap nnm = parent.getAttributes();
for (int i = 0; i < nnm.getLength(); i++) {
Node attr = nnm.item(i);
String aname = attr.getNodeName();
boolean isPrefix = aname.startsWith("xmlns:");
if (isPrefix || aname.equals("xmlns")) {
int index = aname.indexOf(':');
String p =isPrefix ?aname.substring(index + 1) :"";
if (p.equals(prefix)) {
namespace = attr.getNodeValue();
break;
}
}
}
}
parent = parent.getParentNode();
}
}
return namespace;
}
}
1.1 xml-xalan/java/src/org/apache/xpath/jaxp/JAXPVariableStack.java
Index: JAXPVariableStack.java
===================================================================
/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* 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.
*/
// $Id: JAXPVariableStack.java,v 1.1 2005/05/17 17:24:26 mkwan Exp $
package org.apache.xpath.jaxp;
import javax.xml.transform.TransformerException;
import javax.xml.xpath.XPathVariableResolver;
import org.apache.xml.utils.QName;
import org.apache.xpath.VariableStack;
import org.apache.xpath.XPathContext;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.res.XPATHErrorResources;
import org.apache.xalan.res.XSLMessages;
/**
* Overrides {@link VariableStack} and delegates the call to
* {@link javax.xml.xpath.XPathVariableResolver}.
*
* @author Ramesh Mandava ( ramesh.mandava@sun.com )
*/
public class JAXPVariableStack extends VariableStack {
private final XPathVariableResolver resolver;
public JAXPVariableStack(XPathVariableResolver resolver) {
this.resolver = resolver;
}
public XObject getVariableOrParam(XPathContext xctxt, QName qname)
throws TransformerException,IllegalArgumentException {
if ( qname == null ) {
//JAXP 1.3 spec says that if variable name is null then
// we need to through IllegalArgumentException
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_ARG_CANNOT_BE_NULL,
new Object[] {"Variable qname"} );
throw new IllegalArgumentException( fmsg );
}
javax.xml.namespace.QName name =
new javax.xml.namespace.QName(
qname.getNamespace(),
qname.getLocalPart());
Object varValue = resolver.resolveVariable( name );
if ( varValue == null ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_RESOLVE_VARIABLE_RETURNS_NULL,
new Object[] { name.toString()} );
throw new TransformerException( fmsg );
}
return XObject.create( varValue, xctxt );
}
}
1.1 xml-xalan/java/src/org/apache/xpath/jaxp/XPathExpressionImpl.java
Index: XPathExpressionImpl.java
===================================================================
/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* 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.
*/
// $Id: XPathExpressionImpl.java,v 1.1 2005/05/17 17:24:26 mkwan Exp $
package org.apache.xpath.jaxp;
import org.apache.xpath.*;
import javax.xml.transform.TransformerException;
import org.apache.xpath.objects.XObject;
import org.apache.xml.utils.PrefixResolver;
import org.apache.xpath.res.XPATHErrorResources;
import org.apache.xalan.res.XSLMessages;
import javax.xml.namespace.NamespaceContext;
import javax.xml.namespace.QName;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathFunctionResolver;
import javax.xml.xpath.XPathVariableResolver;
import javax.xml.xpath.XPathConstants;
import org.w3c.dom.Node;
import org.w3c.dom.Document;
import org.w3c.dom.DOMImplementation;
import org.w3c.dom.traversal.NodeIterator;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import org.xml.sax.InputSource;
/**
* The XPathExpression interface encapsulates a (compiled) XPath expression.
*
* @version $Revision: 1.1 $
* @author Ramesh Mandava
*/
public class XPathExpressionImpl implements javax.xml.xpath.XPathExpression{
private XPathFunctionResolver functionResolver;
private XPathVariableResolver variableResolver;
private JAXPPrefixResolver prefixResolver;
private org.apache.xpath.XPath xpath;
// By default Extension Functions are allowed in XPath Expressions. If
// Secure Processing Feature is set on XPathFactory then the invocation of
// extensions function need to throw XPathFunctionException
private boolean featureSecureProcessing = false;
/** Protected constructor to prevent direct instantiation; use compile()
* from the context.
*/
protected XPathExpressionImpl() { };
protected XPathExpressionImpl(org.apache.xpath.XPath xpath,
JAXPPrefixResolver prefixResolver,
XPathFunctionResolver functionResolver,
XPathVariableResolver variableResolver ) {
this.xpath = xpath;
this.prefixResolver = prefixResolver;
this.functionResolver = functionResolver;
this.variableResolver = variableResolver;
this.featureSecureProcessing = false;
};
protected XPathExpressionImpl(org.apache.xpath.XPath xpath,
JAXPPrefixResolver prefixResolver,
XPathFunctionResolver functionResolver,
XPathVariableResolver variableResolver,
boolean featureSecureProcessing ) {
this.xpath = xpath;
this.prefixResolver = prefixResolver;
this.functionResolver = functionResolver;
this.variableResolver = variableResolver;
this.featureSecureProcessing = featureSecureProcessing;
};
public void setXPath (org.apache.xpath.XPath xpath ) {
this.xpath = xpath;
}
public Object eval(Object item, QName returnType)
throws javax.xml.transform.TransformerException {
XObject resultObject = eval ( item );
return getResultAsType( resultObject, returnType );
}
private XObject eval ( Object contextItem )
throws javax.xml.transform.TransformerException {
org.apache.xpath.XPathContext xpathSupport = null;
if ( functionResolver != null ) {
JAXPExtensionsProvider jep = new JAXPExtensionsProvider(
functionResolver, featureSecureProcessing );
xpathSupport = new org.apache.xpath.XPathContext( jep );
} else {
xpathSupport = new org.apache.xpath.XPathContext();
}
xpathSupport.setVarStack(new JAXPVariableStack(variableResolver));
XObject xobj = null;
Node contextNode = (Node)contextItem;
// We always need to have a ContextNode with Xalan XPath implementation
// To allow simple expression evaluation like 1+1 we are setting
// dummy Document as Context Node
if ( contextNode == null ) {
contextNode = getDummyDocument();
}
xobj = xpath.execute(xpathSupport, contextNode, prefixResolver );
return xobj;
}
/**
* <p>Evaluate the compiled XPath expression in the specified context and
* return the result as the specified type.</p>
*
* <p>See "Evaluation of XPath Expressions" section of JAXP 1.3 spec
* for context item evaluation,
* variable, function and QName resolution and return type conversion.</p>
*
* <p>If <code>returnType</code> is not one of the types defined
* in {@link XPathConstants},
* then an <code>IllegalArgumentException</code> is thrown.</p>
*
* <p>If a <code>null</code> value is provided for
* <code>item</code>, an empty document will be used for the
* context.
* If <code>returnType</code> is <code>null</code>, then a
* <code>NullPointerException</code> is thrown.</p>
*
* @param item The starting context (node or node list, for example).
* @param returnType The desired return type.
*
* @return The <code>Object</code> that is the result of evaluating the
* expression and converting the result to
* <code>returnType</code>.
*
* @throws XPathExpressionException If the expression cannot be evaluated.
* @throws IllegalArgumentException If <code>returnType</code> is not one
* of the types defined in {@link XPathConstants}.
* @throws NullPointerException If <code>returnType</code> is
* <code>null</code>.
*/
public Object evaluate(Object item, QName returnType)
throws XPathExpressionException {
//Validating parameters to enforce constraints defined by JAXP spec
if ( returnType == null ) {
//Throwing NullPointerException as defined in spec
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_ARG_CANNOT_BE_NULL,
new Object[] {"returnType"} );
throw new NullPointerException( fmsg );
}
// Checking if requested returnType is supported. returnType need to be
// defined in XPathConstants
if ( !isSupported ( returnType ) ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_UNSUPPORTED_RETURN_TYPE,
new Object[] { returnType.toString() } );
throw new IllegalArgumentException ( fmsg );
}
try {
return eval( item, returnType);
} catch ( java.lang.NullPointerException npe ) {
// If VariableResolver returns null Or if we get
// NullPointerException at this stage for some other reason
// then we have to reurn XPathException
throw new XPathExpressionException ( npe );
} catch ( javax.xml.transform.TransformerException te ) {
Throwable nestedException = te.getException();
if ( nestedException instanceof javax.xml.xpath.XPathFunctionException ) {
throw (javax.xml.xpath.XPathFunctionException)nestedException;
} else {
// For any other exceptions we need to throw
// XPathExpressionException ( as per spec )
throw new XPathExpressionException( te);
}
}
}
/**
* <p>Evaluate the compiled XPath expression in the specified context and
* return the result as a <code>String</code>.</p>
*
* <p>This method calls {@link #evaluate(Object item, QName returnType)}
* with a <code>returnType</code> of
* {@link XPathConstants#STRING}.</p>
*
* <p>See "Evaluation of XPath Expressions" section of JAXP 1.3 spec
* for context item evaluation,
* variable, function and QName resolution and return type conversion.</p>
*
* <p>If a <code>null</code> value is provided for
* <code>item</code>, an empty document will be used for the
* context.
*
* @param item The starting context (node or node list, for example).
*
* @return The <code>String</code> that is the result of evaluating the
* expression and converting the result to a
* <code>String</code>.
*
* @throws XPathExpressionException If the expression cannot be evaluated.
*/
public String evaluate(Object item)
throws XPathExpressionException {
return (String)this.evaluate( item, XPathConstants.STRING );
}
static DocumentBuilderFactory dbf = null;
static DocumentBuilder db = null;
static Document d = null;
/**
* <p>Evaluate the compiled XPath expression in the context of the
* specified <code>InputSource</code> and return the result as the
* specified type.</p>
*
* <p>This method builds a data model for the {@link InputSource} and calls
* {@link #evaluate(Object item, QName returnType)} on the resulting
* document object.</p>
*
* <p>See "Evaluation of XPath Expressions" section of JAXP 1.3 spec
* for context item evaluation,
* variable, function and QName resolution and return type conversion.</p>
*
* <p>If <code>returnType</code> is not one of the types defined in
* {@link XPathConstants},
* then an <code>IllegalArgumentException</code> is thrown.</p>
*
*<p>If <code>source</code> or <code>returnType</code> is <code>null</code>,
* then a <code>NullPointerException</code> is thrown.</p>
*
* @param source The <code>InputSource</code> of the document to evaluate
* over.
* @param returnType The desired return type.
*
* @return The <code>Object</code> that is the result of evaluating the
* expression and converting the result to
* <code>returnType</code>.
*
* @throws XPathExpressionException If the expression cannot be evaluated.
* @throws IllegalArgumentException If <code>returnType</code> is not one
* of the types defined in {@link XPathConstants}.
* @throws NullPointerException If <code>source</code> or
* <code>returnType</code> is <code>null</code>.
*/
public Object evaluate(InputSource source, QName returnType)
throws XPathExpressionException {
if ( ( source == null ) || ( returnType == null ) ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_SOURCE_RETURN_TYPE_CANNOT_BE_NULL,
null );
throw new NullPointerException ( fmsg );
}
// Checking if requested returnType is supported. returnType need to be
// defined in XPathConstants
if ( !isSupported ( returnType ) ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_UNSUPPORTED_RETURN_TYPE,
new Object[] { returnType.toString() } );
throw new IllegalArgumentException ( fmsg );
}
try {
if ( dbf == null ) {
dbf = DocumentBuilderFactory.newInstance();
dbf.setNamespaceAware( true );
dbf.setValidating( false );
}
db = dbf.newDocumentBuilder();
Document document = db.parse( source );
return eval( document, returnType );
} catch ( Exception e ) {
throw new XPathExpressionException ( e );
}
}
/**
* <p>Evaluate the compiled XPath expression in the context of the specified <code>InputSource</code> and return the result as a
* <code>String</code>.</p>
*
* <p>This method calls {@link #evaluate(InputSource source, QName returnType)} with a <code>returnType</code> of
* {@link XPathConstants#STRING}.</p>
*
* <p>See "Evaluation of XPath Expressions" section of JAXP 1.3 spec
* for context item evaluation,
* variable, function and QName resolution and return type conversion.</p>
*
* <p>If <code>source</code> is <code>null</code>, then a <code>NullPointerException</code> is thrown.</p>
*
* @param source The <code>InputSource</code> of the document to evaluate over.
*
* @return The <code>String</code> that is the result of evaluating the expression and converting the result to a
* <code>String</code>.
*
* @throws XPathExpressionException If the expression cannot be evaluated.
* @throws NullPointerException If <code>source</code> is <code>null</code>.
*/
public String evaluate(InputSource source)
throws XPathExpressionException {
return (String)this.evaluate( source, XPathConstants.STRING );
}
private boolean isSupported( QName returnType ) {
// XPathConstants.STRING
if ( ( returnType.equals( XPathConstants.STRING ) ) ||
( returnType.equals( XPathConstants.NUMBER ) ) ||
( returnType.equals( XPathConstants.BOOLEAN ) ) ||
( returnType.equals( XPathConstants.NODE ) ) ||
( returnType.equals( XPathConstants.NODESET ) ) ) {
return true;
}
return false;
}
private Object getResultAsType( XObject resultObject, QName returnType )
throws javax.xml.transform.TransformerException {
// XPathConstants.STRING
if ( returnType.equals( XPathConstants.STRING ) ) {
return resultObject.str();
}
// XPathConstants.NUMBER
if ( returnType.equals( XPathConstants.NUMBER ) ) {
return new Double ( resultObject.num());
}
// XPathConstants.BOOLEAN
if ( returnType.equals( XPathConstants.BOOLEAN ) ) {
return new Boolean( resultObject.bool());
}
// XPathConstants.NODESET ---ORdered, UNOrdered???
if ( returnType.equals( XPathConstants.NODESET ) ) {
return resultObject.nodelist();
}
// XPathConstants.NODE
if ( returnType.equals( XPathConstants.NODE ) ) {
NodeIterator ni = resultObject.nodeset();
//Return the first node, or null
return ni.nextNode();
}
// If isSupported check is already done then the execution path
// shouldn't come here. Being defensive
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_UNSUPPORTED_RETURN_TYPE,
new Object[] { returnType.toString()});
throw new IllegalArgumentException ( fmsg );
}
private static Document getDummyDocument( ) {
try {
if ( dbf == null ) {
dbf = DocumentBuilderFactory.newInstance();
dbf.setNamespaceAware( true );
dbf.setValidating( false );
}
db = dbf.newDocumentBuilder();
DOMImplementation dim = db.getDOMImplementation();
d = dim.createDocument("http://java.sun.com/jaxp/xpath",
"dummyroot", null);
return d;
} catch ( Exception e ) {
e.printStackTrace();
}
return null;
}
}
1.1 xml-xalan/java/src/org/apache/xpath/jaxp/XPathFactoryImpl.java
Index: XPathFactoryImpl.java
===================================================================
/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* 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.
*/
// $Id: XPathFactoryImpl.java,v 1.1 2005/05/17 17:24:26 mkwan Exp $
package org.apache.xpath.jaxp;
import org.apache.xpath.res.XPATHErrorResources;
import org.apache.xalan.res.XSLMessages;
import javax.xml.XMLConstants;
import javax.xml.xpath.XPathFactory;
import javax.xml.xpath.XPathFactoryConfigurationException;
import javax.xml.xpath.XPathFunctionResolver;
import javax.xml.xpath.XPathVariableResolver;
/**
* The XPathFactory builds XPaths.
*
* @version $Revision: 1.1 $
* @author Ramesh Mandava
*/
public class XPathFactoryImpl extends XPathFactory {
/**
* <p>Name of class as a constant to use for debugging.</p>
*/
private static final String CLASS_NAME = "XPathFactoryImpl";
/**
*<p>XPathFunctionResolver for this XPathFactory and created XPaths.</p>
*/
private XPathFunctionResolver xPathFunctionResolver = null;
/**
* <p>XPathVariableResolver for this XPathFactory and created XPaths</p>
*/
private XPathVariableResolver xPathVariableResolver = null;
/**
* <p>State of secure processing feature.</p>
*/
private boolean featureSecureProcessing = false;
/**
* <p>Is specified object model supported by this
* <code>XPathFactory</code>?</p>
*
* @param objectModel Specifies the object model which the returned
* <code>XPathFactory</code> will understand.
*
* @return <code>true</code> if <code>XPathFactory</code> supports
* <code>objectModel</code>, else <code>false</code>.
*
* @throws NullPointerException If <code>objectModel</code> is <code>null</code>.
* @throws IllegalArgumentException If <code>objectModel.length() == 0</code>.
*/
public boolean isObjectModelSupported(String objectModel) {
if (objectModel == null) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_OBJECT_MODEL_NULL,
new Object[] { this.getClass().getName() } );
throw new NullPointerException( fmsg );
}
if (objectModel.length() == 0) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_OBJECT_MODEL_EMPTY,
new Object[] { this.getClass().getName() } );
throw new IllegalArgumentException( fmsg );
}
// know how to support default object model, W3C DOM
if (objectModel.equals(XPathFactory.DEFAULT_OBJECT_MODEL_URI)) {
return true;
}
// don't know how to support anything else
return false;
}
/**
* <p>Returns a new <code>XPath</code> object using the underlying
* object model determined when the factory was instantiated.</p>
*
* @return New <code>XPath</code>
*/
public javax.xml.xpath.XPath newXPath() {
return new org.apache.xpath.jaxp.XPathImpl(
xPathVariableResolver, xPathFunctionResolver,
featureSecureProcessing );
}
/**
* <p>Set a feature for this <code>XPathFactory</code> and
* <code>XPath</code>s created by this factory.</p>
*
* <p>
* Feature names are fully qualified {@link java.net.URI}s.
* Implementations may define their own features.
* An {@link XPathFactoryConfigurationException} is thrown if this
* <code>XPathFactory</code> or the <code>XPath</code>s
* it creates cannot support the feature.
* It is possible for an <code>XPathFactory</code> to expose a feature
* value but be unable to change its state.
* </p>
*
* <p>See {@link javax.xml.xpath.XPathFactory} for full documentation
* of specific features.</p>
*
* @param name Feature name.
* @param value Is feature state <code>true</code> or <code>false</code>.
*
* @throws XPathFactoryConfigurationException if this
* <code>XPathFactory</code> or the <code>XPath</code>s
* it creates cannot support this feature.
* @throws NullPointerException if <code>name</code> is
* <code>null</code>.
*/
public void setFeature(String name, boolean value)
throws XPathFactoryConfigurationException {
// feature name cannot be null
if (name == null) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_FEATURE_NAME_NULL,
new Object[] { CLASS_NAME, new Boolean( value) } );
throw new NullPointerException( fmsg );
}
// secure processing?
if (name.equals(XMLConstants.FEATURE_SECURE_PROCESSING)) {
featureSecureProcessing = value;
// all done processing feature
return;
}
// unknown feature
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_FEATURE_UNKNOWN,
new Object[] { name, CLASS_NAME, new Boolean(value) } );
throw new XPathFactoryConfigurationException( fmsg );
}
/**
* <p>Get the state of the named feature.</p>
*
* <p>
* Feature names are fully qualified {@link java.net.URI}s.
* Implementations may define their own features.
* An {@link XPathFactoryConfigurationException} is thrown if this
* <code>XPathFactory</code> or the <code>XPath</code>s
* it creates cannot support the feature.
* It is possible for an <code>XPathFactory</code> to expose a feature
* value but be unable to change its state.
* </p>
*
* @param name Feature name.
*
* @return State of the named feature.
*
* @throws XPathFactoryConfigurationException if this
* <code>XPathFactory</code> or the <code>XPath</code>s
* it creates cannot support this feature.
* @throws NullPointerException if <code>name</code> is
* <code>null</code>.
*/
public boolean getFeature(String name)
throws XPathFactoryConfigurationException {
// feature name cannot be null
if (name == null) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_GETTING_NULL_FEATURE,
new Object[] { CLASS_NAME } );
throw new NullPointerException( fmsg );
}
// secure processing?
if (name.equals(XMLConstants.FEATURE_SECURE_PROCESSING)) {
return featureSecureProcessing;
}
// unknown feature
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_GETTING_UNKNOWN_FEATURE,
new Object[] { name, CLASS_NAME } );
throw new XPathFactoryConfigurationException( fmsg );
}
/**
* <p>Establish a default function resolver.</p>
*
* <p>Any <code>XPath</code> objects constructed from this factory will use
* the specified resolver by default.</p>
*
* <p>A <code>NullPointerException</code> is thrown if
* <code>resolver</code> is <code>null</code>.</p>
*
* @param resolver XPath function resolver.
*
* @throws NullPointerException If <code>resolver</code> is
* <code>null</code>.
*/
public void setXPathFunctionResolver(XPathFunctionResolver resolver) {
// resolver cannot be null
if (resolver == null) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_NULL_XPATH_FUNCTION_RESOLVER,
new Object[] { CLASS_NAME } );
throw new NullPointerException( fmsg );
}
xPathFunctionResolver = resolver;
}
/**
* <p>Establish a default variable resolver.</p>
*
* <p>Any <code>XPath</code> objects constructed from this factory will use
* the specified resolver by default.</p>
*
* <p>A <code>NullPointerException</code> is thrown if <code>resolver</code> is <code>null</code>.</p>
*
* @param resolver Variable resolver.
*
* @throws NullPointerException If <code>resolver</code> is
* <code>null</code>.
*/
public void setXPathVariableResolver(XPathVariableResolver resolver) {
// resolver cannot be null
if (resolver == null) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_NULL_XPATH_VARIABLE_RESOLVER,
new Object[] { CLASS_NAME } );
throw new NullPointerException( fmsg );
}
xPathVariableResolver = resolver;
}
}
1.1 xml-xalan/java/src/org/apache/xpath/jaxp/XPathImpl.java
Index: XPathImpl.java
===================================================================
/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* 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.
*/
// $Id: XPathImpl.java,v 1.1 2005/05/17 17:24:26 mkwan Exp $
package org.apache.xpath.jaxp;
import javax.xml.namespace.QName;
import javax.xml.namespace.NamespaceContext;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathFunctionResolver;
import javax.xml.xpath.XPathVariableResolver;
import javax.xml.xpath.XPathExpression;
import org.apache.xml.dtm.DTM;
import org.apache.xpath.*;
import org.apache.xpath.objects.XObject;
import org.apache.xpath.res.XPATHErrorResources;
import org.apache.xalan.res.XSLMessages;
import org.w3c.dom.Node;
import org.w3c.dom.DOMImplementation;
import org.w3c.dom.Document;
import org.w3c.dom.traversal.NodeIterator;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import javax.xml.parsers.*;
import java.io.IOException;
/**
* The XPathImpl class provides implementation for the methods defined in
* javax.xml.xpath.XPath interface. This provide simple access to the results
* of an XPath expression.
*
*
* @version $Revision: 1.1 $
* @author Ramesh Mandava
*/
public class XPathImpl implements javax.xml.xpath.XPath {
// Private variables
private XPathVariableResolver variableResolver;
private XPathFunctionResolver functionResolver;
private XPathVariableResolver origVariableResolver;
private XPathFunctionResolver origFunctionResolver;
private NamespaceContext namespaceContext=null;
private JAXPPrefixResolver prefixResolver;
// By default Extension Functions are allowed in XPath Expressions. If
// Secure Processing Feature is set on XPathFactory then the invocation of
// extensions function need to throw XPathFunctionException
private boolean featureSecureProcessing = false;
XPathImpl( XPathVariableResolver vr, XPathFunctionResolver fr ) {
this.origVariableResolver = this.variableResolver = vr;
this.origFunctionResolver = this.functionResolver = fr;
}
XPathImpl( XPathVariableResolver vr, XPathFunctionResolver fr,
boolean featureSecureProcessing ) {
this.origVariableResolver = this.variableResolver = vr;
this.origFunctionResolver = this.functionResolver = fr;
this.featureSecureProcessing = featureSecureProcessing;
}
/**
* <p>Establishes a variable resolver.</p>
*
* @param resolver Variable Resolver
*/
public void setXPathVariableResolver(XPathVariableResolver resolver) {
if ( resolver == null ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_ARG_CANNOT_BE_NULL,
new Object[] {"XPathVariableResolver"} );
throw new NullPointerException( fmsg );
}
this.variableResolver = resolver;
}
/**
* <p>Returns the current variable resolver.</p>
*
* @return Current variable resolver
*/
public XPathVariableResolver getXPathVariableResolver() {
return variableResolver;
}
/**
* <p>Establishes a function resolver.</p>
*
* @param resolver XPath function resolver
*/
public void setXPathFunctionResolver(XPathFunctionResolver resolver) {
if ( resolver == null ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_ARG_CANNOT_BE_NULL,
new Object[] {"XPathFunctionResolver"} );
throw new NullPointerException( fmsg );
}
this.functionResolver = resolver;
}
/**
* <p>Returns the current function resolver.</p>
*
* @return Current function resolver
*/
public XPathFunctionResolver getXPathFunctionResolver() {
return functionResolver;
}
/**
* <p>Establishes a namespace context.</p>
*
* @param nsContext Namespace context to use
*/
public void setNamespaceContext(NamespaceContext nsContext) {
if ( nsContext == null ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_ARG_CANNOT_BE_NULL,
new Object[] {"NamespaceContext"} );
throw new NullPointerException( fmsg );
}
this.namespaceContext = nsContext;
this.prefixResolver = new JAXPPrefixResolver ( nsContext );
}
/**
* <p>Returns the current namespace context.</p>
*
* @return Current Namespace context
*/
public NamespaceContext getNamespaceContext() {
return namespaceContext;
}
private static Document d = null;
private static DocumentBuilder getParser() {
try {
// we'd really like to cache those DocumentBuilders, but we can't because:
// 1. thread safety. parsers are not thread-safe, so at least
// we need one instance per a thread.
// 2. parsers are non-reentrant, so now we are looking at having a
// pool of parsers.
// 3. then the class loading issue. The look-up procedure of
// DocumentBuilderFactory.newInstance() depends on context class loader
// and system properties, which may change during the execution of JVM.
//
// so we really have to create a fresh DocumentBuilder every time we need one
// - KK
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
dbf.setNamespaceAware( true );
dbf.setValidating( false );
return dbf.newDocumentBuilder();
} catch (ParserConfigurationException e) {
// this should never happen with a well-behaving JAXP implementation.
throw new Error(e.toString());
}
}
private static Document getDummyDocument( ) {
// we don't need synchronization here; even if two threads
// enter this code at the same time, we just waste a little time
if(d==null) {
DOMImplementation dim = getParser().getDOMImplementation();
d = dim.createDocument("http://java.sun.com/jaxp/xpath",
"dummyroot", null);
}
return d;
}
private XObject eval(String expression, Object contextItem)
throws javax.xml.transform.TransformerException {
org.apache.xpath.XPath xpath = new org.apache.xpath.XPath( expression,
null, prefixResolver, org.apache.xpath.XPath.SELECT );
org.apache.xpath.XPathContext xpathSupport = null;
if ( functionResolver != null ) {
JAXPExtensionsProvider jep = new JAXPExtensionsProvider(
functionResolver, featureSecureProcessing );
xpathSupport = new org.apache.xpath.XPathContext( jep );
} else {
xpathSupport = new org.apache.xpath.XPathContext();
}
XObject xobj = null;
xpathSupport.setVarStack(new JAXPVariableStack(variableResolver));
// If item is null, then we will create a a Dummy contextNode
if ( contextItem instanceof Node ) {
xobj = xpath.execute (xpathSupport, (Node)contextItem,
prefixResolver );
} else {
xobj = xpath.execute ( xpathSupport, DTM.NULL, prefixResolver );
}
return xobj;
}
/**
* <p>Evaluate an <code>XPath</code> expression in the specified context and return the result as the specified type.</p>
*
* <p>See "Evaluation of XPath Expressions" section of JAXP 1.3 spec
* for context item evaluation,
* variable, function and <code>QName</code> resolution and return type conversion.</p>
*
* <p>If <code>returnType</code> is not one of the types defined in {@link XPathConstants} (
* {@link XPathConstants#NUMBER NUMBER},
* {@link XPathConstants#STRING STRING},
* {@link XPathConstants#BOOLEAN BOOLEAN},
* {@link XPathConstants#NODE NODE} or
* {@link XPathConstants#NODESET NODESET})
* then an <code>IllegalArgumentException</code> is thrown.</p>
*
* <p>If a <code>null</code> value is provided for
* <code>item</code>, an empty document will be used for the
* context.
* If <code>expression</code> or <code>returnType</code> is <code>null</code>, then a
* <code>NullPointerException</code> is thrown.</p>
*
* @param expression The XPath expression.
* @param item The starting context (node or node list, for example).
* @param returnType The desired return type.
*
* @return Result of evaluating an XPath expression as an <code>Object</code> of <code>returnType</code>.
*
* @throws XPathExpressionException If <code>expression</code> cannot be evaluated.
* @throws IllegalArgumentException If <code>returnType</code> is not one of the types defined in {@link XPathConstants}.
* @throws NullPointerException If <code>expression</code> or <code>returnType</code> is <code>null</code>.
*/
public Object evaluate(String expression, Object item, QName returnType)
throws XPathExpressionException {
if ( expression == null ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_ARG_CANNOT_BE_NULL,
new Object[] {"XPath expression"} );
throw new NullPointerException ( fmsg );
}
if ( returnType == null ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_ARG_CANNOT_BE_NULL,
new Object[] {"returnType"} );
throw new NullPointerException ( fmsg );
}
// Checking if requested returnType is supported. returnType need to
// be defined in XPathConstants
if ( !isSupported ( returnType ) ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_UNSUPPORTED_RETURN_TYPE,
new Object[] { returnType.toString() } );
throw new IllegalArgumentException ( fmsg );
}
try {
XObject resultObject = eval( expression, item );
return getResultAsType( resultObject, returnType );
} catch ( java.lang.NullPointerException npe ) {
// If VariableResolver returns null Or if we get
// NullPointerException at this stage for some other reason
// then we have to reurn XPathException
throw new XPathExpressionException ( npe );
} catch ( javax.xml.transform.TransformerException te ) {
Throwable nestedException = te.getException();
if ( nestedException instanceof javax.xml.xpath.XPathFunctionException ) {
throw (javax.xml.xpath.XPathFunctionException)nestedException;
} else {
// For any other exceptions we need to throw
// XPathExpressionException ( as per spec )
throw new XPathExpressionException ( te );
}
}
}
private boolean isSupported( QName returnType ) {
if ( ( returnType.equals( XPathConstants.STRING ) ) ||
( returnType.equals( XPathConstants.NUMBER ) ) ||
( returnType.equals( XPathConstants.BOOLEAN ) ) ||
( returnType.equals( XPathConstants.NODE ) ) ||
( returnType.equals( XPathConstants.NODESET ) ) ) {
return true;
}
return false;
}
private Object getResultAsType( XObject resultObject, QName returnType )
throws javax.xml.transform.TransformerException {
// XPathConstants.STRING
if ( returnType.equals( XPathConstants.STRING ) ) {
return resultObject.str();
}
// XPathConstants.NUMBER
if ( returnType.equals( XPathConstants.NUMBER ) ) {
return new Double ( resultObject.num());
}
// XPathConstants.BOOLEAN
if ( returnType.equals( XPathConstants.BOOLEAN ) ) {
return new Boolean( resultObject.bool());
}
// XPathConstants.NODESET ---ORdered, UNOrdered???
if ( returnType.equals( XPathConstants.NODESET ) ) {
return resultObject.nodelist();
}
// XPathConstants.NODE
if ( returnType.equals( XPathConstants.NODE ) ) {
NodeIterator ni = resultObject.nodeset();
//Return the first node, or null
return ni.nextNode();
}
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_UNSUPPORTED_RETURN_TYPE,
new Object[] { returnType.toString()});
throw new IllegalArgumentException( fmsg );
}
/**
* <p>Evaluate an XPath expression in the specified context and return the result as a <code>String</code>.</p>
*
* <p>This method calls {@link #evaluate(String expression, Object item, QName returnType)} with a <code>returnType</code> of
* {@link XPathConstants#STRING}.</p>
*
* <p>See "Evaluation of XPath Expressions" of JAXP 1.3 spec
* for context item evaluation,
* variable, function and QName resolution and return type conversion.</p>
*
* <p>If a <code>null</code> value is provided for
* <code>item</code>, an empty document will be used for the
* context.
* If <code>expression</code> is <code>null</code>, then a <code>NullPointerException</code> is thrown.</p>
*
* @param expression The XPath expression.
* @param item The starting context (node or node list, for example).
*
* @return The <code>String</code> that is the result of evaluating the expression and
* converting the result to a <code>String</code>.
*
* @throws XPathExpressionException If <code>expression</code> cannot be evaluated.
* @throws NullPointerException If <code>expression</code> is <code>null</code>.
*/
public String evaluate(String expression, Object item)
throws XPathExpressionException {
return (String)this.evaluate( expression, item, XPathConstants.STRING );
}
/**
* <p>Compile an XPath expression for later evaluation.</p>
*
* <p>If <code>expression</code> contains any {@link XPathFunction}s,
* they must be available via the {@link XPathFunctionResolver}.
* An {@link XPathExpressionException} will be thrown if the <code>XPathFunction</code>
* cannot be resovled with the <code>XPathFunctionResolver</code>.</p>
*
* <p>If <code>expression</code> is <code>null</code>, a <code>NullPointerException</code> is thrown.</p>
*
* @param expression The XPath expression.
*
* @return Compiled XPath expression.
* @throws XPathExpressionException If <code>expression</code> cannot be compiled.
* @throws NullPointerException If <code>expression</code> is <code>null</code>.
*/
public XPathExpression compile(String expression)
throws XPathExpressionException {
if ( expression == null ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_ARG_CANNOT_BE_NULL,
new Object[] {"XPath expression"} );
throw new NullPointerException ( fmsg );
}
try {
org.apache.xpath.XPath xpath = new XPath (expression, null,
prefixResolver, org.apache.xpath.XPath.SELECT );
// Can have errorListener
XPathExpressionImpl ximpl = new XPathExpressionImpl (xpath,
prefixResolver, functionResolver, variableResolver,
featureSecureProcessing );
return ximpl;
} catch ( javax.xml.transform.TransformerException te ) {
throw new XPathExpressionException ( te ) ;
}
}
/**
* <p>Evaluate an XPath expression in the context of the specified <code>InputSource</code>
* and return the result as the specified type.</p>
*
* <p>This method builds a data model for the {@link InputSource} and calls
* {@link #evaluate(String expression, Object item, QName returnType)} on the resulting document object.</p>
*
* <p>See "Evaluation of XPath Expressions" section of JAXP 1.3 spec
* for context item evaluation,
* variable, function and QName resolution and return type conversion.</p>
*
* <p>If <code>returnType</code> is not one of the types defined in {@link XPathConstants},
* then an <code>IllegalArgumentException</code> is thrown.</p>
*
* <p>If <code>expression</code>, <code>source</code> or <code>returnType</code> is <code>null</code>,
* then a <code>NullPointerException</code> is thrown.</p>
*
* @param expression The XPath expression.
* @param source The input source of the document to evaluate over.
* @param returnType The desired return type.
*
* @return The <code>Object</code> that encapsulates the result of evaluating the expression.
*
* @throws XPathExpressionException If expression cannot be evaluated.
* @throws IllegalArgumentException If <code>returnType</code> is not one of the types defined in {@link XPathConstants}.
* @throws NullPointerException If <code>expression</code>, <code>source</code> or <code>returnType</code>
* is <code>null</code>.
*/
public Object evaluate(String expression, InputSource source,
QName returnType) throws XPathExpressionException {
// Checking validity of different parameters
if( source== null ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_ARG_CANNOT_BE_NULL,
new Object[] {"source"} );
throw new NullPointerException ( fmsg );
}
if ( expression == null ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_ARG_CANNOT_BE_NULL,
new Object[] {"XPath expression"} );
throw new NullPointerException ( fmsg );
}
if ( returnType == null ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_ARG_CANNOT_BE_NULL,
new Object[] {"returnType"} );
throw new NullPointerException ( fmsg );
}
//Checking if requested returnType is supported.
//returnType need to be defined in XPathConstants
if ( !isSupported ( returnType ) ) {
String fmsg = XSLMessages.createXPATHMessage(
XPATHErrorResources.ER_UNSUPPORTED_RETURN_TYPE,
new Object[] { returnType.toString() } );
throw new IllegalArgumentException ( fmsg );
}
try {
Document document = getParser().parse( source );
XObject resultObject = eval( expression, document );
return getResultAsType( resultObject, returnType );
} catch ( SAXException e ) {
throw new XPathExpressionException ( e );
} catch( IOException e ) {
throw new XPathExpressionException ( e );
} catch ( javax.xml.transform.TransformerException te ) {
Throwable nestedException = te.getException();
if ( nestedException instanceof javax.xml.xpath.XPathFunctionException ) {
throw (javax.xml.xpath.XPathFunctionException)nestedException;
} else {
throw new XPathExpressionException ( te );
}
}
}
/**
* <p>Evaluate an XPath expression in the context of the specified <code>InputSource</code>
* and return the result as a <code>String</code>.</p>
*
* <p>This method calls {@link #evaluate(String expression, InputSource source, QName returnType)} with a
* <code>returnType</code> of {@link XPathConstants#STRING}.</p>
*
* <p>See "Evaluation of XPath Expressions" section of JAXP 1.3 spec
* for context item evaluation,
* variable, function and QName resolution and return type conversion.</p>
*
* <p>If <code>expression</code> or <code>source</code> is <code>null</code>,
* then a <code>NullPointerException</code> is thrown.</p>
*
* @param expression The XPath expression.
* @param source The <code>InputSource</code> of the document to evaluate over.
*
* @return The <code>String</code> that is the result of evaluating the expression and
* converting the result to a <code>String</code>.
*
* @throws XPathExpressionException If expression cannot be evaluated.
* @throws NullPointerException If <code>expression</code> or <code>source</code> is <code>null</code>.
*/
public String evaluate(String expression, InputSource source)
throws XPathExpressionException {
return (String)this.evaluate( expression, source, XPathConstants.STRING );
}
/**
* <p>Reset this <code>XPath</code> to its original configuration.</p>
*
* <p><code>XPath</code> is reset to the same state as when it was created with
* {@link XPathFactory#newXPath()}.
* <code>reset()</code> is designed to allow the reuse of existing <code>XPath</code>s
* thus saving resources associated with the creation of new <code>XPath</code>s.</p>
*
* <p>The reset <code>XPath</code> is not guaranteed to have the same
* {@link XPathFunctionResolver}, {@link XPathVariableResolver}
* or {@link NamespaceContext} <code>Object</code>s, e.g. {@link Object#equals(Object obj)}.
* It is guaranteed to have a functionally equal <code>XPathFunctionResolver</code>,
* <code>XPathVariableResolver</code>
* and <code>NamespaceContext</code>.</p>
*/
public void reset() {
this.variableResolver = this.origVariableResolver;
this.functionResolver = this.origFunctionResolver;
this.namespaceContext = null;
}
}
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