methodresolver.java

来自「java jdk 1.4的源码」· Java 代码 · 共 1,035 行 · 第 1/3 页

          }
          else
            return -1;
        }
        else
          return -1;
      }
    }
    return score;
  }
  
  /**
   * Convert the given XSLT object to an object of 
   * the given class.
   * @param xsltObj The XSLT object that needs conversion.
   * @param javaClass The type of object to convert to.
   * @returns An object suitable for passing to the Method.invoke 
   * function in the args array, which may be null in some cases.
   * @throws TransformerException may be thrown for Xalan conversion
   * exceptions.
   */
  static Object convert(Object xsltObj, Class javaClass)
    throws javax.xml.transform.TransformerException
  {
    if(xsltObj instanceof XObject)
    {
      XObject xobj = ((XObject)xsltObj);
      int xsltClassType = xobj.getType();

      switch(xsltClassType)
      {
      case XObject.CLASS_NULL:
        return null;
        
      case XObject.CLASS_BOOLEAN:
        {
          if(javaClass == java.lang.String.class)
            return xobj.str();
          else
            return new Boolean(xobj.bool());
        }
        // break; Unreachable
      case XObject.CLASS_NUMBER:
        {
          if(javaClass == java.lang.String.class)
            return xobj.str();
          else if(javaClass == Boolean.TYPE)
            return new Boolean(xobj.bool());
          else 
          {
            return convertDoubleToNumber(xobj.num(), javaClass);
          }
        }
        // break; Unreachable
        
      case XObject.CLASS_STRING:
        {
          if((javaClass == java.lang.String.class) ||
             (javaClass == java.lang.Object.class))
            return xobj.str();
          else if(javaClass == Character.TYPE)
          {
            String str = xobj.str();
            if(str.length() > 0)
              return new Character(str.charAt(0));
            else
              return null; // ??
          }
          else if(javaClass == Boolean.TYPE)
            return new Boolean(xobj.bool());
          else 
          {
            return convertDoubleToNumber(xobj.num(), javaClass);
          }
        }
        // break; Unreachable
        
      case XObject.CLASS_RTREEFRAG:
        {
          // GLP:  I don't see the reason for the isAssignableFrom call
          //       instead of an == test as is used everywhere else.
          //       Besides, if the javaClass is a subclass of NodeIterator
          //       the condition will be true and we'll create a NodeIterator
          //       which may not match the javaClass, causing a RuntimeException.
          // if((NodeIterator.class.isAssignableFrom(javaClass)) ||
          if ( (javaClass == NodeIterator.class) ||
               (javaClass == java.lang.Object.class) )
          {
            DTMIterator dtmIter = ((XRTreeFrag) xobj).asNodeIterator();
            return new DTMNodeIterator(dtmIter);
          }
          else if (javaClass == NodeList.class)
          {
            return ((XRTreeFrag) xobj).convertToNodeset();
          }
          // Same comment as above
          // else if(Node.class.isAssignableFrom(javaClass))
          else if(javaClass == Node.class)
          {
            DTMIterator iter = ((XRTreeFrag) xobj).asNodeIterator();
            int rootHandle = iter.nextNode();
            DTM dtm = iter.getDTM(rootHandle);
            return dtm.getNode(dtm.getFirstChild(rootHandle));
          }
          else if(javaClass == java.lang.String.class)
          {
            return xobj.str();
          }
          else if(javaClass == Boolean.TYPE)
          {
            return new Boolean(xobj.bool());
          }
          else if(javaClass.isPrimitive())
          {
            return convertDoubleToNumber(xobj.num(), javaClass);
          }
          else
          {
            DTMIterator iter = ((XRTreeFrag) xobj).asNodeIterator();
            int rootHandle = iter.nextNode();
            DTM dtm = iter.getDTM(rootHandle);
            Node child = dtm.getNode(dtm.getFirstChild(rootHandle));

            if(javaClass.isAssignableFrom(child.getClass()))
              return child;
            else
              return null;
          }
        }
        // break; Unreachable
        
      case XObject.CLASS_NODESET:
        {
          // GLP:  I don't see the reason for the isAssignableFrom call
          //       instead of an == test as is used everywhere else.
          //       Besides, if the javaClass is a subclass of NodeIterator
          //       the condition will be true and we'll create a NodeIterator
          //       which may not match the javaClass, causing a RuntimeException.
          // if((NodeIterator.class.isAssignableFrom(javaClass)) ||
          if ( (javaClass == NodeIterator.class) ||
               (javaClass == java.lang.Object.class) )
          {
            return xobj.nodeset();
          }
          // Same comment as above
          // else if(NodeList.class.isAssignableFrom(javaClass))
          else if(javaClass == NodeList.class)
          {
            return xobj.nodelist();
          }
          // Same comment as above
          // else if(Node.class.isAssignableFrom(javaClass))
          else if(javaClass == Node.class)
          {
            // Xalan ensures that iter() always returns an
            // iterator positioned at the beginning.
            DTMIterator ni = xobj.iter();
            int handle = ni.nextNode();
            if (handle != DTM.NULL)
              return ni.getDTM(handle).getNode(handle); // may be null.
            else
              return null;
          }
          else if(javaClass == java.lang.String.class)
          {
            return xobj.str();
          }
          else if(javaClass == Boolean.TYPE)
          {
            return new Boolean(xobj.bool());
          }
          else if(javaClass.isPrimitive())
          {
            return convertDoubleToNumber(xobj.num(), javaClass);
          }
          else
          {
            DTMIterator iter = xobj.iter();
            int childHandle = iter.nextNode();
            DTM dtm = iter.getDTM(childHandle);
            Node child = dtm.getNode(childHandle);
            if(javaClass.isAssignableFrom(child.getClass()))
              return child;
            else
              return null;
          }
        }
        // break; Unreachable
        
        // No default:, fall-through on purpose
      } // end switch
      xsltObj = xobj.object();
      
    } // end if if(xsltObj instanceof XObject)
    
    // At this point, we have a raw java object, not an XObject.
    if (null != xsltObj)
    {
      if(javaClass == java.lang.String.class)
      {
        return xsltObj.toString();
      }
      else if(javaClass.isPrimitive())
      {
        // Assume a number conversion
        XString xstr = new XString(xsltObj.toString());
        double num = xstr.num();
        return convertDoubleToNumber(num, javaClass);
      }
      else if(javaClass == java.lang.Class.class)
      {
        return xsltObj.getClass();
      }
      else
      {
        // Just pass the object directly, and hope for the best.
        return xsltObj;
      }
                }
    else
    {
      // Just pass the object directly, and hope for the best.
      return xsltObj;
    }
  }
  
  /**
   * Do a standard conversion of a double to the specified type.
   * @param num The number to be converted.
   * @param javaClass The class type to be converted to.
   * @return An object specified by javaClass, or a Double instance.
   */
  static Object convertDoubleToNumber(double num, Class javaClass)
  {
    // In the code below, I don't check for NaN, etc., instead 
    // using the standard Java conversion, as I think we should 
    // specify.  See issue-runtime-errors.
    if((javaClass == Double.TYPE) ||
       (javaClass == java.lang.Double.class))
      return new Double(num);
    else if(javaClass == Float.TYPE)
      return new Float(num);
    else if(javaClass == Long.TYPE)
    {
      // Use standard Java Narrowing Primitive Conversion
      // See http://java.sun.com/docs/books/jls/html/5.doc.html#175672
      return new Long((long)num);
    }
    else if(javaClass == Integer.TYPE)
    {
      // Use standard Java Narrowing Primitive Conversion
      // See http://java.sun.com/docs/books/jls/html/5.doc.html#175672
      return new Integer((int)num);
    }
    else if(javaClass == Short.TYPE)
    {
      // Use standard Java Narrowing Primitive Conversion
      // See http://java.sun.com/docs/books/jls/html/5.doc.html#175672
      return new Short((short)num);
    }
    else if(javaClass == Character.TYPE)
    {
      // Use standard Java Narrowing Primitive Conversion
      // See http://java.sun.com/docs/books/jls/html/5.doc.html#175672
      return new Character((char)num);
    }
    else if(javaClass == Byte.TYPE)
    {
      // Use standard Java Narrowing Primitive Conversion
      // See http://java.sun.com/docs/books/jls/html/5.doc.html#175672
      return new Byte((byte)num);
    }
    else     // Some other type of object
    {
      return new Double(num);
    }
  }


  /**
   * Format the message for the NoSuchMethodException containing 
   * all the information about the method we're looking for.
   */
  private static String errString(String callType,    // "function" or "element"
                                  String searchType,  // "method" or "constructor"
                                  Class classObj,
                                  String funcName,
                                  int searchMethod,
                                  Object[] xsltArgs)
  {
    String resultString = "For extension " + callType
                                              + ", could not find " + searchType + " ";
    switch (searchMethod)
    {
      case STATIC_ONLY:
        return resultString + "static " + classObj.getName() + "." 
                            + funcName + "([ExpressionContext,] " + errArgs(xsltArgs, 0) + ").";

      case INSTANCE_ONLY:
        return resultString + classObj.getName() + "."
                            + funcName + "([ExpressionContext,] " + errArgs(xsltArgs, 0) + ").";

      case STATIC_AND_INSTANCE:
        return resultString + classObj.getName() + "." + funcName + "([ExpressionContext,] " + errArgs(xsltArgs, 0) + ").\n"
                            + "Checked both static and instance methods.";

      case DYNAMIC:
        return resultString + "static " + classObj.getName() + "." + funcName
                            + "([ExpressionContext, ]" + errArgs(xsltArgs, 0) + ") nor\n"
                            + classObj + "." + funcName + "([ExpressionContext,] " + errArgs(xsltArgs, 1) + ").";

      default:
        if (callType.equals("function"))      // must be a constructor
        {
          return resultString + classObj.getName()
                                  + "([ExpressionContext,] " + errArgs(xsltArgs, 0) + ").";
        }
        else                                  // must be an element call
        {
          return resultString + classObj.getName() + "." + funcName
                    + "(org.apache.xalan.extensions.XSLProcessorContext, "
                    + "org.apache.xalan.templates.ElemExtensionCall).";
        }
    }
    
  }


  private static String errArgs(Object[] xsltArgs, int startingArg)
  {
    StringBuffer returnArgs = new StringBuffer();
    for (int i = startingArg; i < xsltArgs.length; i++)
    {
      if (i != startingArg)
        returnArgs.append(", ");
      if (xsltArgs[i] instanceof XObject)
        returnArgs.append(((XObject) xsltArgs[i]).getTypeString());      
      else
        returnArgs.append(xsltArgs[i].getClass().getName());
    }
    return returnArgs.toString();
  }

}