/*
* 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: ExtensionHandlerJavaPackage.java,v 1.22 2005/05/30 17:39:40 mkwan Exp $
*/
package org.apache.xalan.extensions;
import java.io.IOException;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Vector;
import javax.xml.transform.TransformerException;
import org.apache.xalan.res.XSLMessages;
import org.apache.xalan.res.XSLTErrorResources;
import org.apache.xalan.templates.ElemTemplateElement;
import org.apache.xalan.templates.Stylesheet;
import org.apache.xalan.trace.ExtensionEvent;
import org.apache.xalan.transformer.TransformerImpl;
import org.apache.xpath.functions.FuncExtFunction;
import org.apache.xpath.objects.XObject;
/**
* Represents an extension namespace for XPath that handles java packages
* that may be fully or partially specified.
* It is recommended that the class URI be of one of the following forms:
* <pre>
* xalan://partial.class.name
* xalan://
* http://xml.apache.org/xalan/java (which is the same as xalan://)
* </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>
*
* @xsl.usage internal
*/
public class ExtensionHandlerJavaPackage extends ExtensionHandlerJava
{
/**
* 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 beginning of the class name of the class. This
* should be followed by a dot (.)
*/
public ExtensionHandlerJavaPackage(String namespaceUri,
String scriptLang,
String className)
{
super(namespaceUri, scriptLang, className);
}
/**
* Tests whether a certain function name is known within this namespace.
* Since this is for a package, we concatenate the package name used when
* this handler was created and the function name specified in the argument.
* 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)
{
try
{
String fullName = m_className + function;
int lastDot = fullName.lastIndexOf(".");
if (lastDot >= 0)
{
Class myClass = getClassForName(fullName.substring(0, lastDot));
Method[] methods = myClass.getMethods();
int nMethods = methods.length;
function = fullName.substring(lastDot + 1);
for (int i = 0; i < nMethods; i++)
{
if (methods[i].getName().equals(function))
return true;
}
}
}
catch (ClassNotFoundException cnfe) {}
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)
{
try
{
String fullName = m_className + element;
int lastDot = fullName.lastIndexOf(".");
if (lastDot >= 0)
{
Class myClass = getClassForName(fullName.substring(0, lastDot));
Method[] methods = myClass.getMethods();
int nMethods = methods.length;
element = fullName.substring(lastDot + 1);
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;
}
}
}
}
}
catch (ClassNotFoundException cnfe) {}
return false;
}
/**
* Process a call to a function in the package java namespace.
* There are three possible types of calls:
* <pre>
* Constructor:
* packagens:class.name.new(arg1, arg2, ...)
*
* Static method:
* packagens:class.name.method(arg1, arg2, ...)
*
* Instance method:
* packagens: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 ends with a ".new", call the best constructor for
* class whose name is formed by concatenating the value specified on
* the namespace with the value specified in the function invocation
* before ".new".</li>
* <li>If the function name contains a period, call the best static method "method"
* in the class whose name is formed by concatenating the value specified on
* the namespace with the value specified in the function invocation.</li>
* <li>Otherwise, call the best instance method "method"
* in the class whose name is formed by concatenating the value specified on
* the namespace with the value specified in the function invocation.
* Note that a static method of the same
* name will <i>not</i> be called in the current implementation. This
* module does not verify that the obj argument is a member of the
* package namespace.</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 javax.xml.transform.TransformerException if parsing trouble
*/
public Object callFunction (String funcName,
Vector args,
Object methodKey,
ExpressionContext exprContext)
throws TransformerException
{
String className;
String methodName;
Class classObj;
Object targetObject;
int lastDot = funcName.lastIndexOf(".");
Object[] methodArgs;
Object[][] convertedArgs;
Class[] paramTypes;
try
{
TransformerImpl trans = (exprContext != null) ?
(TransformerImpl)exprContext.getXPathContext().getOwnerObject() : null;
if (funcName.endsWith(".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 = (methodKey != null) ?
(Constructor) getFromCache(methodKey, null, methodArgs) : null;
if (c != null)
{
try
{
paramTypes = c.getParameterTypes();
MethodResolver.convertParams(methodArgs, convertedArgs, paramTypes, exprContext);
return c.newInstance(convertedArgs[0]);
}
catch (InvocationTargetException ite)
{
throw ite;
}
catch(Exception e)
{
// Must not have been the right one
}
}
className = m_className + funcName.substring(0, lastDot);
try
{
classObj = getClassForName(className);
}
catch (ClassNotFoundException e)
{
throw new TransformerException(e);
}
c = MethodResolver.getConstructor(classObj,
methodArgs,
convertedArgs,
exprContext);
if (methodKey != null)
putToCache(methodKey, null, methodArgs, c);
if (trans != null && trans.getDebug()) {
trans.getTraceManager().fireExtensionEvent(new ExtensionEvent(trans, c, convertedArgs[0]));
Object result;
try {
result = c.newInstance(convertedArgs[0]);
} catch (Exception e) {
throw e;
} finally {
trans.getTraceManager().fireExtensionEndEvent(new ExtensionEvent(trans, c, convertedArgs[0]));
}
return result;
} else
return c.newInstance(convertedArgs[0]);
}
else if (-1 != lastDot) { // Handle static method call
methodArgs = new Object[args.size()];
convertedArgs = new Object[1][];
for (int i = 0; i < methodArgs.length; i++)
{
methodArgs[i] = args.elementAt(i);
}
Method m = (methodKey != null) ?
(Method) getFromCache(methodKey, null, methodArgs) : null;
if (m != null && !trans.getDebug())
{
try
{
paramTypes = m.getParameterTypes();
MethodResolver.convertParams(methodArgs, convertedArgs, paramTypes, exprContext);
return m.invoke(null, convertedArgs[0]);
}
catch (InvocationTargetException ite)
{
throw ite;
}
catch(Exception e)
{
// Must not have been the right one
}
}
className = m_className + funcName.substring(0, lastDot);
methodName = funcName.substring(lastDot + 1);
try
{
classObj = getClassForName(className);
}
catch (ClassNotFoundException e)
{
throw new TransformerException(e);
}
m = MethodResolver.getMethod(classObj,
methodName,
methodArgs,
convertedArgs,
exprContext,
MethodResolver.STATIC_ONLY);
if (methodKey != null)
putToCache(methodKey, null, methodArgs, m);
if (trans != null && trans.getDebug()) {
trans.getTraceManager().fireExtensionEvent(m, null, convertedArgs[0]);
Object result;
try {
result = m.invoke(null, convertedArgs[0]);
} catch (Exception e) {
throw e;
} finally {
trans.getTraceManager().fireExtensionEndEvent(m, null, convertedArgs[0]);
}
return result;
}
else
return m.invoke(null, convertedArgs[0]);
}
else { // Handle instance method call
if (args.size() < 1)
{
throw new TransformerException(XSLMessages.createMessage(XSLTErrorResources.ER_INSTANCE_MTHD_CALL_REQUIRES, new Object[]{funcName })); //"Instance method call to method " + funcName
//+ " requires an Object instance as first argument");
}
targetObject = args.elementAt(0);
if (targetObject instanceof XObject) // Next level down for XObjects
targetObject = ((XObject) targetObject).object();
methodArgs = new Object[args.size() - 1];
convertedArgs = new Object[1][];
for (int i = 0; i < methodArgs.length; i++)
{
methodArgs[i] = args.elementAt(i+1);
}
Method m = (methodKey != null) ?
(Method) getFromCache(methodKey, targetObject, methodArgs) : null;
if (m != null)
{
try
{
paramTypes = m.getParameterTypes();
MethodResolver.convertParams(methodArgs, convertedArgs, paramTypes, exprContext);
return m.invoke(targetObject, convertedArgs[0]);
}
catch (InvocationTargetException ite)
{
throw ite;
}
catch(Exception e)
{
// Must not have been the right one
}
}
classObj = targetObject.getClass();
m = MethodResolver.getMethod(classObj,
funcName,
methodArgs,
convertedArgs,
exprContext,
MethodResolver.INSTANCE_ONLY);
if (methodKey != null)
putToCache(methodKey, targetObject, methodArgs, m);
if (trans != null && trans.getDebug()) {
trans.getTraceManager().fireExtensionEvent(m, targetObject, convertedArgs[0]);
Object result;
try {
result = m.invoke(targetObject, convertedArgs[0]);
} catch (Exception e) {
throw e;
} finally {
trans.getTraceManager().fireExtensionEndEvent(m, targetObject, convertedArgs[0]);
}
return result;
} else
return m.invoke(targetObject, convertedArgs[0]);
}
}
catch (InvocationTargetException ite)
{
Throwable resultException = ite;
Throwable targetException = ite.getTargetException();
if (targetException instanceof TransformerException)
throw ((TransformerException)targetException);
else if (targetException != null)
resultException = targetException;
throw new TransformerException(resultException);
}
catch (Exception e)
{
// e.printStackTrace();
throw new TransformerException(e);
}
}
/**
* Process a call to an XPath extension function
*
* @param extFunction The XPath extension function
* @param args The arguments of the function call.
* @param exprContext The context in which this expression is being executed.
* @return the return value of the function evaluation.
* @throws javax.xml.transform.TransformerException
*/
public Object callFunction(FuncExtFunction extFunction,
Vector args,
ExpressionContext exprContext)
throws TransformerException
{
return callFunction(extFunction.getFunctionName(), args,
extFunction.getMethodKey(), exprContext);
}
/**
* Process a call to this extension namespace via an element. As a side
* effect, the results are sent to the TransformerImpl's result tree.
* For this namespace, only static element methods are currently supported.
* If instance methods are needed, please let us know your requirements.
* @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 methodKey A key that uniquely identifies this element call.
* @throws java.io.IOException if loading trouble
* @throws javax.xml.transform.TransformerException if parsing trouble
*/
public void processElement (String localPart,
ElemTemplateElement element,
TransformerImpl transformer,
Stylesheet stylesheetTree,
Object methodKey)
throws TransformerException, IOException
{
Object result = null;
Class classObj;
Method m = (Method) getFromCache(methodKey, null, null);
if (null == m)
{
try
{
String fullName = m_className + localPart;
int lastDot = fullName.lastIndexOf(".");
if (lastDot < 0)
throw new TransformerException(XSLMessages.createMessage(XSLTErrorResources.ER_INVALID_ELEMENT_NAME, new Object[]{fullName })); //"Invalid element name specified " + fullName);
try
{
classObj = getClassForName(fullName.substring(0, lastDot));
}
catch (ClassNotFoundException e)
{
throw new TransformerException(e);
}
localPart = fullName.substring(lastDot + 1);
m = MethodResolver.getElementMethod(classObj, localPart);
if (!Modifier.isStatic(m.getModifiers()))
throw new TransformerException(XSLMessages.createMessage(XSLTErrorResources.ER_ELEMENT_NAME_METHOD_STATIC, new Object[]{fullName })); //"Element name method must be static " + fullName);
}
catch (Exception e)
{
// e.printStackTrace ();
throw new TransformerException (e);
}
putToCache(methodKey, null, null, m);
}
XSLProcessorContext xpc = new XSLProcessorContext(transformer,
stylesheetTree);
try
{
if (transformer.getDebug()) {
transformer.getTraceManager().fireExtensionEvent(m, null, new Object[] {xpc, element});
try {
result = m.invoke(null, new Object[] {xpc, element});
} catch (Exception e) {
throw e;
} finally {
transformer.getTraceManager().fireExtensionEndEvent(m, null, new Object[] {xpc, element});
}
} else
result = m.invoke(null, new Object[] {xpc, element});
}
catch (InvocationTargetException ite)
{
Throwable resultException = ite;
Throwable targetException = ite.getTargetException();
if (targetException instanceof TransformerException)
throw ((TransformerException)targetException);
else if (targetException != null)
resultException = targetException;
throw new TransformerException(resultException);
}
catch (Exception e)
{
// e.printStackTrace ();
throw new TransformerException (e);
}
if (result != null)
{
xpc.outputToResultTree (stylesheetTree, result);
}
}
}