/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Xalan" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation and was
* originally based on software copyright (c) 1999, Lotus
* Development Corporation., http://www.lotus.com. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.xalan.extensions;
import java.util.Vector;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.io.IOException;
//import org.w3c.dom.Element;
//import org.w3c.dom.Node;
import org.apache.xalan.transformer.TransformerImpl;
import org.apache.xalan.templates.Stylesheet;
import org.apache.xalan.templates.ElemTemplateElement;
import org.apache.xml.utils.QName;
import org.apache.xpath.objects.XObject;
import javax.xml.transform.TransformerException;
/**
* <meta name="usage" content="internal"/>
* Represents an extension namespace for XPath that handles java classes.
* It is recommended that the class URI be of the form:
* <pre>
* xalan://fully.qualified.class.name
* </pre>
* However, we do not enforce this. If the class name contains a
* a /, we only use the part to the right of the rightmost slash.
* In addition, we ignore any "class:" prefix.
* Provides functions to test a function's existence and call a function.
* Also provides functions to test an element's existence and call an
* element.
*
* @author <a href="mailto:garyp@firstech.com">Gary L Peskin</a>
*/
public class ExtensionHandlerJavaClass extends ExtensionHandlerJava
{
private Class m_classObj = null;
/**
* Provides a default Instance for use by elements that need to call
* an instance method.
*/
private Object m_defaultInstance = null;
/**
* Construct a new extension namespace handler given all the information
* needed.
* @param namespaceUri the extension namespace URI that I'm implementing
* @param scriptLang language of code implementing the extension
* @param className the fully qualified class name of the class
*/
public ExtensionHandlerJavaClass(String namespaceUri,
String scriptLang,
String className)
{
super(namespaceUri, scriptLang, className);
try
{
m_classObj = getClassForName(className);
}
catch (ClassNotFoundException e)
{
// For now, just let this go. We'll catch it when we try to invoke a method.
}
}
/**
* Tests whether a certain function name is known within this namespace.
* Simply looks for a method with the appropriate name. There is
* no information regarding the arguments to the function call or
* whether the method implementing the function is a static method or
* an instance method.
* @param function name of the function being tested
* @return true if its known, false if not.
*/
public boolean isFunctionAvailable(String function)
{
Method[] methods = m_classObj.getMethods();
int nMethods = methods.length;
for (int i = 0; i < nMethods; i++)
{
if (methods[i].getName().equals(function))
return true;
}
return false;
}
/**
* Tests whether a certain element name is known within this namespace.
* Looks for a method with the appropriate name and signature.
* This method examines both static and instance methods.
* @param element name of the element being tested
* @return true if its known, false if not.
*/
public boolean isElementAvailable(String element)
{
Method[] methods = m_classObj.getMethods();
int nMethods = methods.length;
for (int i = 0; i < nMethods; i++)
{
if (methods[i].getName().equals(element))
{
Class[] paramTypes = methods[i].getParameterTypes();
if ( (paramTypes.length == 2)
&& paramTypes[0].isAssignableFrom(
org.apache.xalan.extensions.XSLProcessorContext.class)
&& paramTypes[1].isAssignableFrom(org.apache.xalan.templates.ElemExtensionCall.class) )
{
return true;
}
}
}
return false;
}
/**
* Process a call to a function in the java class represented by
* this <code>ExtensionHandlerJavaClass<code>.
* There are three possible types of calls:
* <pre>
* Constructor:
* classns:new(arg1, arg2, ...)
*
* Static method:
* classns:method(arg1, arg2, ...)
*
* Instance method:
* classns:method(obj, arg1, arg2, ...)
* </pre>
* We use the following rules to determine the type of call made:
* <ol type="1">
* <li>If the function name is "new", call the best constructor for
* class represented by the namespace URI</li>
* <li>If the first argument to the function is of the class specified
* in the namespace or is a subclass of that class, look for the best
* method of the class specified in the namespace with the specified
* arguments. Compare all static and instance methods with the correct
* method name. For static methods, use all arguments in the compare.
* For instance methods, use all arguments after the first.</li>
* <li>Otherwise, select the best static or instance method matching
* all of the arguments. If the best method is an instance method,
* call the function using a default object, creating it if needed.</li>
* </ol>
*
* @param funcName Function name.
* @param args The arguments of the function call.
* @param methodKey A key that uniquely identifies this class and method call.
* @param exprContext The context in which this expression is being executed.
* @return the return value of the function evaluation.
* @throws TransformerException
*/
public Object callFunction (String funcName,
Vector args,
Object methodKey,
ExpressionContext exprContext)
throws TransformerException
{
Object[] methodArgs;
Object[][] convertedArgs;
Class[] paramTypes;
try
{
if (funcName.equals("new")) { // Handle constructor call
methodArgs = new Object[args.size()];
convertedArgs = new Object[1][];
for (int i = 0; i < methodArgs.length; i++)
{
methodArgs[i] = args.elementAt(i);
}
Constructor c = (Constructor) getFromCache(methodKey, null, methodArgs);
if (c != null)
{
try
{
paramTypes = c.getParameterTypes();
MethodResolver.convertParams(methodArgs, convertedArgs, paramTypes, exprContext);
return c.newInstance(convertedArgs[0]);
}
catch(Exception e)
{
// Must not have been the right one
}
}
c = MethodResolver.getConstructor(m_classObj,
methodArgs,
convertedArgs,
exprContext);
putToCache(methodKey, null, methodArgs, c);
return c.newInstance(convertedArgs[0]);
}
else
{
int resolveType;
Object targetObject = null;
methodArgs = new Object[args.size()];
convertedArgs = new Object[1][];
for (int i = 0; i < methodArgs.length; i++)
{
methodArgs[i] = args.elementAt(i);
}
Method m = (Method) getFromCache(methodKey, null, methodArgs);
if (m != null)
{
try
{
paramTypes = m.getParameterTypes();
MethodResolver.convertParams(methodArgs, convertedArgs, paramTypes, exprContext);
if (Modifier.isStatic(m.getModifiers()))
return m.invoke(null, convertedArgs[0]);
else
{
// This is tricky. We get the actual number of target arguments (excluding any
// ExpressionContext). If we passed in the same number, we need the implied object.
int nTargetArgs = convertedArgs[0].length;
if (ExpressionContext.class.isAssignableFrom(paramTypes[0]))
nTargetArgs--;
if (methodArgs.length <= nTargetArgs)
return m.invoke(m_defaultInstance, convertedArgs[0]);
else
return m.invoke(methodArgs[0], convertedArgs[0]);
}
}
catch(Exception e)
{
// Must not have been the right one
}
}
if (args.size() > 0)
{
targetObject = methodArgs[0];
if (targetObject instanceof XObject)
targetObject = ((XObject) targetObject).object();
if (m_classObj.isAssignableFrom(targetObject.getClass()))
resolveType = MethodResolver.DYNAMIC;
else
resolveType = MethodResolver.STATIC_AND_INSTANCE;
}
else
{
targetObject = null;
resolveType = MethodResolver.STATIC_AND_INSTANCE;
}
m = MethodResolver.getMethod(m_classObj,
funcName,
methodArgs,
convertedArgs,
exprContext,
resolveType);
putToCache(methodKey, null, methodArgs, m);
if (MethodResolver.DYNAMIC == resolveType) // First argument was object type
return m.invoke(targetObject, convertedArgs[0]);
else // First arg was not object. See if we need the implied object.
{
if (Modifier.isStatic(m.getModifiers()))
return m.invoke(null, convertedArgs[0]);
else
{
if (null == m_defaultInstance)
{
m_defaultInstance = m_classObj.newInstance();
}
return m.invoke(m_defaultInstance, convertedArgs[0]);
}
}
}
}
catch (InvocationTargetException ite)
{
Throwable realException = ite.getTargetException();
if (realException instanceof Exception)
throw new TransformerException((Exception) realException);
else
throw new TransformerException(ite);
}
catch (Exception e)
{
// e.printStackTrace();
throw new TransformerException(e);
}
}
/**
* Process a call to this extension namespace via an element. As a side
* effect, the results are sent to the TransformerImpl's result tree.
* We invoke the static or instance method in the class represented by
* by the namespace URI. If we don't already have an instance of this class,
* we create one upon the first call.
*
* @param localPart Element name's local part.
* @param element The extension element being processed.
* @param transformer Handle to TransformerImpl.
* @param stylesheetTree The compiled stylesheet tree.
* @param sourceTree The root of the source tree (but don't assume
* it's a Document).
* @param sourceNode The current context node.
* @param mode The current mode.
* @param methodKey A key that uniquely identifies this element call.
* @throws IOException if loading trouble
* @throws TransformerException if parsing trouble
*/
public void processElement(String localPart,
ElemTemplateElement element,
TransformerImpl transformer,
Stylesheet stylesheetTree,
Object methodKey)
throws TransformerException, IOException
{
Object result = null;
Method m = (Method) getFromCache(methodKey, null, null);
if (null == m)
{
try
{
m = MethodResolver.getElementMethod(m_classObj, localPart);
if ( (null == m_defaultInstance) && !Modifier.isStatic(m.getModifiers()) )
m_defaultInstance = m_classObj.newInstance();
}
catch (Exception e)
{
// e.printStackTrace ();
throw new TransformerException (e.getMessage (), e);
}
putToCache(methodKey, null, null, m);
}
XSLProcessorContext xpc = new XSLProcessorContext(transformer,
stylesheetTree);
try
{
result = m.invoke(m_defaultInstance, new Object[] {xpc, element});
}
catch (Exception e)
{
// e.printStackTrace ();
throw new TransformerException (e.getMessage (), e);
}
if (result != null)
{
xpc.outputToResultTree (stylesheetTree, result);
}
}
}