extensionhandlerjavaclass.java

来自「java jdk 1.4的源码」· Java 代码 · 共 459 行 · 第 1/2 页

    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 (InvocationTargetException ite)
          {
            throw ite;
          }
          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  
              {
                targetObject = methodArgs[0];
                
                if (targetObject instanceof XObject)
                  targetObject = ((XObject) targetObject).object();
                  
                return m.invoke(targetObject, convertedArgs[0]);
              }
            }
          }
          catch (InvocationTargetException ite)
          {
            throw ite;
          }
          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 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 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 (InvocationTargetException e)
    {
      Throwable targetException = e.getTargetException();
      
      if (targetException instanceof TransformerException)
        throw (TransformerException)targetException;
      else if (targetException != null)
        throw new TransformerException (targetException.getMessage (), targetException);
      else
        throw new TransformerException (e.getMessage (), e);
    }
    catch (Exception e)
    {
      // e.printStackTrace ();
      throw new TransformerException (e.getMessage (), e);
    }

    if (result != null)
    {
      xpc.outputToResultTree (stylesheetTree, result);
    }
 
  }
 
}