javax.xml.xpath.XPathFunction#org.apache.xpath.res.XPATHErrorResources源码实例Demo

/**
 *
 * Basis    ::=    AxisName '::' NodeTest
 * | AbbreviatedBasis
 *
 * @return FROM_XXX axes type, found in {@link org.apache.xpath.compiler.Keywords}.
 *
 * @throws javax.xml.transform.TransformerException
 */
protected int AxisName() throws javax.xml.transform.TransformerException
{

  Object val = Keywords.getAxisName(m_token);

  if (null == val)
  {
    error(XPATHErrorResources.ER_ILLEGAL_AXIS_NAME,
          new Object[]{ m_token });  //"illegal axis name: "+m_token);
  }

  int axesType = ((Integer) val).intValue();

  appendOp(2, axesType);

  return axesType;
}
 

/**
 * Set the root node of the TreeWalker.
 * (Not part of the DOM2 TreeWalker interface).
 *
 * @param root The context node of this step.
 */
public void setRoot(int root)
{
  // %OPT% Get this directly from the lpi.
  XPathContext xctxt = wi().getXPathContext();
  m_dtm = xctxt.getDTM(root);
  m_traverser = m_dtm.getAxisTraverser(m_axis);
  m_isFresh = true;
  m_foundLast = false;
  m_root = root;
  m_currentNode = root;

  if (DTM.NULL == root)
  {
    throw new RuntimeException(
      XSLMessages.createXPATHMessage(XPATHErrorResources.ER_SETTING_WALKER_ROOT_TO_NULL, null)); //"\n !!!! Error! Setting the root of a walker to null!!!");
  }

  resetProximityPositions();
}
 

/**
 *  Returns the previous node in the set and moves the position of the
 * iterator backwards in the set.
 * @return  The previous <code>Node</code> in the set being iterated over,
 *   or<code>DTM.NULL</code> if there are no more members in that set.
 * @throws DOMException
 *    INVALID_STATE_ERR: Raised if this method is called after the
 *   <code>detach</code> method was invoked.
 * @throws RuntimeException thrown if this NodeSetDTM is not of 
 * a cached type, and hence doesn't know what the previous node was.
 */
public int previousNode()
{

  if (!m_cacheNodes)
    throw new RuntimeException(
      XSLMessages.createXPATHMessage(XPATHErrorResources.ER_NODESETDTM_CANNOT_ITERATE, null)); //"This NodeSetDTM can not iterate to a previous node!");

  if ((m_next - 1) > 0)
  {
    m_next--;

    return this.elementAt(m_next);
  }
  else
    return DTM.NULL;
}
 

/**
 *  Returns the previous node in the set and moves the position of the
 * iterator backwards in the set.
 * @return  The previous <code>Node</code> in the set being iterated over,
 *   or<code>null</code> if there are no more members in that set.
 * @throws DOMException
 *    INVALID_STATE_ERR: Raised if this method is called after the
 *   <code>detach</code> method was invoked.
 * @throws RuntimeException thrown if this NodeSet is not of 
 * a cached type, and hence doesn't know what the previous node was.
 */
public Node previousNode() throws DOMException
{

  if (!m_cacheNodes)
    throw new RuntimeException(
      XSLMessages.createXPATHMessage(XPATHErrorResources.ER_NODESET_CANNOT_ITERATE, null)); //"This NodeSet can not iterate to a previous node!");

  if ((m_next - 1) > 0)
  {
    m_next--;

    return this.elementAt(m_next);
  }
  else
    return null;
}
 

/**
 * Copy NodeList members into this nodelist, adding in
 * document order.  If a node is null, don't add it.
 *
 * @param nodelist List of nodes which should now be referenced by
 * this NodeSet.
 * @throws RuntimeException thrown if this NodeSet is not of 
 * a mutable type.
 */
public void addNodes(NodeList nodelist)
{

  if (!m_mutable)
    throw new RuntimeException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_NODESET_NOT_MUTABLE, null)); //"This NodeSet is not mutable!");

  if (null != nodelist)  // defensive to fix a bug that Sanjiva reported.
  {
    int nChildren = nodelist.getLength();

    for (int i = 0; i < nChildren; i++)
    {
      Node obj = nodelist.item(i);

      if (null != obj)
      {
        addElement(obj);
      }
    }
  }

  // checkDups();
}
 

/**
 * Copy NodeList members into this nodelist, adding in
 * document order.  Null references are not added.
 *
 * @param iterator NodeIterator which yields the nodes to be added.
 * @throws RuntimeException thrown if this NodeSet is not of 
 * a mutable type.
 */
public void addNodes(NodeIterator iterator)
{

  if (!m_mutable)
    throw new RuntimeException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_NODESET_NOT_MUTABLE, null)); //"This NodeSet is not mutable!");

  if (null != iterator)  // defensive to fix a bug that Sanjiva reported.
  {
    Node obj;

    while (null != (obj = iterator.nextNode()))
    {
      addElement(obj);
    }
  }

  // checkDups();
}
 

/**
 * Copy NodeList members into this nodelist, adding in
 * document order.  If a node is null, don't add it.
 *
 * @param nodelist List of nodes to be added
 * @param support The XPath runtime context.
 * @throws RuntimeException thrown if this NodeSet is not of 
 * a mutable type.
 */
public void addNodesInDocOrder(NodeList nodelist, XPathContext support)
{

  if (!m_mutable)
    throw new RuntimeException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_NODESET_NOT_MUTABLE, null)); //"This NodeSet is not mutable!");

  int nChildren = nodelist.getLength();

  for (int i = 0; i < nChildren; i++)
  {
    Node node = nodelist.item(i);

    if (null != node)
    {
      addNodeInDocOrder(node, support);
    }
  }
}
 

/**
 * Tell the user of an assertion error, and probably throw an
 * exception.
 *
 * @param b  If false, a TransformerException will be thrown.
 * @param msg The assertion message, which should be informative.
 * 
 * @throws javax.xml.transform.TransformerException if b is false.
 */
private void assertion(boolean b, String msg) throws javax.xml.transform.TransformerException
{
  if (!b) 
  {
    ErrorListener errorHandler = getErrorListener();

    if (errorHandler != null)
    {
      errorHandler.fatalError(
        new TransformerException(
          XSLMessages.createMessage(
            XPATHErrorResources.ER_INCORRECT_PROGRAMMER_ASSERTION,
            new Object[]{ msg }), (SAXSourceLocator)this.getSAXLocator()));
    }
  }
}
 

/**
 * 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;
  }
   

}
 

/**
 * <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 ) ;
    }
}
 

/**
 * Get a local variable or parameter in the current stack frame.
 *
 *
 * @param xctxt The XPath context, which must be passed in order to
 * lazy evaluate variables.
 *
 * @param index Local variable index relative to the current stack
 * frame bottom.
 *
 * @return The value of the variable.
 *
 * @throws TransformerException
 */
public XObject getLocalVariable(XPathContext xctxt, int index, boolean destructiveOK)
        throws TransformerException
{

  index += _currentFrameBottom;

  XObject val = _stackFrames[index];
  
  if(null == val)
    throw new TransformerException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_VARIABLE_ACCESSED_BEFORE_BIND, null),
                   xctxt.getSAXLocator());
    // "Variable accessed before it is bound!", xctxt.getSAXLocator());

  // Lazy execution of variables.
  if (val.getType() == XObject.CLASS_UNRESOLVEDVARIABLE)
    return (_stackFrames[index] = val.execute(xctxt));

  return destructiveOK ? val : val.getFresh();
}
 

/**
 * Cast result object to a number. Always issues an error.
 *
 * @return 0.0
 *
 * @throws javax.xml.transform.TransformerException
 */
public double num() throws javax.xml.transform.TransformerException
{

  error(XPATHErrorResources.ER_CANT_CONVERT_TO_NUMBER,
        new Object[]{ getTypeString() });  //"Can not convert "+getTypeString()+" to a number");

  return 0.0;
}
 

/**
 * Cast result object to a boolean. Always issues an error.
 *
 * @return false
 *
 * @throws javax.xml.transform.TransformerException
 */
public boolean bool() throws javax.xml.transform.TransformerException
{

  error(XPATHErrorResources.ER_CANT_CONVERT_TO_NUMBER,
        new Object[]{ getTypeString() });  //"Can not convert "+getTypeString()+" to a number");

  return false;
}
 

/**
 * Cast result object to a nodelist. Always issues an error.
 *
 * @return null
 *
 * @throws javax.xml.transform.TransformerException
 */
public DTMIterator iter() throws javax.xml.transform.TransformerException
{

  error(XPATHErrorResources.ER_CANT_CONVERT_TO_NODELIST,
        new Object[]{ getTypeString() });  //"Can not convert "+getTypeString()+" to a NodeList!");

  return null;
}
 

/**
 * Cast result object to a nodelist. Always issues an error.
 *
 * @return null
 *
 * @throws javax.xml.transform.TransformerException
 */
public NodeIterator nodeset() throws javax.xml.transform.TransformerException
{

  error(XPATHErrorResources.ER_CANT_CONVERT_TO_NODELIST,
        new Object[]{ getTypeString() });  //"Can not convert "+getTypeString()+" to a NodeList!");

  return null;
}
 

/**
 * Cast result object to a nodelist. Always issues an error.
 *
 * @return null
 *
 * @throws javax.xml.transform.TransformerException
 */
public NodeList nodelist() throws javax.xml.transform.TransformerException
{

  error(XPATHErrorResources.ER_CANT_CONVERT_TO_NODELIST,
        new Object[]{ getTypeString() });  //"Can not convert "+getTypeString()+" to a NodeList!");

  return null;
}
 

/**
 * Cast result object to a nodelist. Always issues an error.
 *
 * @return The object as a NodeSetDTM.
 *
 * @throws javax.xml.transform.TransformerException
 */
public NodeSetDTM mutableNodeset()
        throws javax.xml.transform.TransformerException
{

  error(XPATHErrorResources.ER_CANT_CONVERT_TO_MUTABLENODELIST,
        new Object[]{ getTypeString() });  //"Can not convert "+getTypeString()+" to a NodeSetDTM!");

  return (NodeSetDTM) m_obj;
}
 

/**
 * Construct a XNodeSet object.
 *
 * @param val FastStringBuffer object this will wrap, must be non-null.
 * @param start The start position in the array.
 * @param length The number of characters to read from the array.
 */
public XStringForChars(char[] val, int start, int length)
{
  super(val);
  m_start = start;
  m_length = length;
  if(null == val)
    throw new IllegalArgumentException(
                        XSLMessages.createXPATHMessage(XPATHErrorResources.ER_FASTSTRINGBUFFER_CANNOT_BE_NULL, null)); //"The FastStringBuffer argument can not be null!!");
}
 

/**
 * Construct a XNodeSet object.
 *
 * @param val String object this will wrap.
 */
private XStringForChars(String val)
{
  super(val);
  throw new IllegalArgumentException(
                    XSLMessages.createXPATHMessage(XPATHErrorResources.ER_XSTRINGFORCHARS_CANNOT_TAKE_STRING, null)); //"XStringForChars can not take a string for an argument!");
}
 

/**
 * Construct a XNodeSet object.
 *
 * @param val FastStringBuffer object this will wrap, must be non-null.
 * @param start The start position in the array.
 * @param length The number of characters to read from the array.
 */
public XStringForFSB(FastStringBuffer val, int start, int length)
{

  super(val);

  m_start = start;
  m_length = length;

  if (null == val)
    throw new IllegalArgumentException(
      XSLMessages.createXPATHMessage(XPATHErrorResources.ER_FASTSTRINGBUFFER_CANNOT_BE_NULL, null));
}
 

/**
 * Construct a XNodeSet object.
 *
 * @param val String object this will wrap.
 */
private XStringForFSB(String val)
{

  super(val);

  throw new IllegalArgumentException(
    XSLMessages.createXPATHMessage(XPATHErrorResources.ER_FSB_CANNOT_TAKE_STRING, null)); // "XStringForFSB can not take a string for an argument!");
}
 

/**
  * Cast result object to a number.
  *
  * @return The result tree fragment as a number or NaN
  */
 public double num()
   throws javax.xml.transform.TransformerException
 {

throw new RuntimeException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_NUM_NOT_SUPPORTED_XRTREEFRAGSELECTWRAPPER, null)); //"num() not supported by XRTreeFragSelectWrapper!");
 }
 

/**
 * This function is used to fixup variables from QNames to stack frame 
 * indexes at stylesheet build time.
 * @param vars List of QNames that correspond to variables.  This list 
 * should be searched backwards for the first qualified name that 
 * corresponds to the variable reference qname.  The position of the 
 * QName in the vector from the start of the vector will be its position 
 * in the stack frame (but variables above the globalsTop value will need 
 * to be offset to the current stack frame).
 */
public void fixupVariables(java.util.Vector vars, int globalsSize)
{
  m_fixUpWasCalled = true;
  int sz = vars.size();

  for (int i = vars.size()-1; i >= 0; i--) 
  {
    QName qn = (QName)vars.elementAt(i);
    // System.out.println("qn: "+qn);
    if(qn.equals(m_qname))
    {
      
      if(i < globalsSize)
      {
        m_isGlobal = true;
        m_index = i;
      }
      else
      {
        m_index = i-globalsSize;
      }
        
      return;
    }
  }
  
  java.lang.String msg = XSLMessages.createXPATHMessage(XPATHErrorResources.ER_COULD_NOT_FIND_VAR, 
                                           new Object[]{m_qname.toString()});
                                           
  TransformerException te = new TransformerException(msg, this);
                                           
  throw new org.apache.xml.utils.WrappedRuntimeException(te);
  
}
 

/**
 * Tell the user of an assertion error, and probably throw an
 * exception.
 *
 * @param b  If false, a runtime exception will be thrown.
 * @param msg The assertion message, which should be informative.
 *
 * @throws RuntimeException if the b argument is false.
 *
 * @throws javax.xml.transform.TransformerException
 */
public void assertion(boolean b, java.lang.String msg)
{

  if (!b)
  {
    java.lang.String fMsg = XSLMessages.createXPATHMessage(
      XPATHErrorResources.ER_INCORRECT_PROGRAMMER_ASSERTION,
      new Object[]{ msg });

    throw new RuntimeException(fMsg);
  }
}
 

/**
 * If an index is requested, NodeSetDTM will call this method
 * to run the iterator to the index.  By default this sets
 * m_next to the index.  If the index argument is -1, this
 * signals that the iterator should be run to the end.
 *
 * @param index Position to advance (or retreat) to, with
 * 0 requesting the reset ("fresh") position and -1 (or indeed
 * any out-of-bounds value) requesting the final position.
 * @throws RuntimeException thrown if this NodeSetDTM is not
 * one of the types which supports indexing/counting.
 */
public void runTo(int index)
{

  if (!m_cacheNodes)
    throw new RuntimeException(
      XSLMessages.createXPATHMessage(XPATHErrorResources.ER_NODESETDTM_CANNOT_INDEX, null)); //"This NodeSetDTM can not do indexing or counting functions!");

  if ((index >= 0) && (m_next < m_firstFree))
    m_next = index;
  else
    m_next = m_firstFree - 1;
}
 

/**
 * Given an FROM_stepType position, return the position of the
 * first predicate, if there is one, or else this will point
 * to the end of the FROM_stepType.
 * Example:
 *  int posOfPredicate = xpath.getNextOpPos(stepPos);
 *  boolean hasPredicates =
 *            OpCodes.OP_PREDICATE == xpath.getOp(posOfPredicate);
 *
 * @param opPos position of FROM_stepType op. 
 * @return position of predicate in FROM_stepType structure.
 */
public int getFirstPredicateOpPos(int opPos)
   throws javax.xml.transform.TransformerException
{

  int stepType = m_opMap.elementAt(opPos);

  if ((stepType >= OpCodes.AXES_START_TYPES)
          && (stepType <= OpCodes.AXES_END_TYPES))
  {
    return opPos + m_opMap.elementAt(opPos + 2);
  }
  else if ((stepType >= OpCodes.FIRST_NODESET_OP)
           && (stepType <= OpCodes.LAST_NODESET_OP))
  {
    return opPos + m_opMap.elementAt(opPos + 1);
  }
  else if(-2 == stepType)
  {
    return -2;
  }
  else
  {
    error(org.apache.xpath.res.XPATHErrorResources.ER_UNKNOWN_OPCODE,
          new Object[]{ String.valueOf(stepType) });  //"ERROR! Unknown op code: "+m_opMap[opPos]);
    return -1;
  }
}
 

/**
 * Remove a node.
 *
 * @param n Node to be added
 * @throws RuntimeException thrown if this NodeSetDTM is not of 
 * a mutable type.
 */
public void removeNode(int n)
{

  if (!m_mutable)
    throw new RuntimeException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_NODESETDTM_NOT_MUTABLE, null)); //"This NodeSetDTM is not mutable!");

  this.removeElement(n);
}
 

/**
 * Execute the function.  The function must return
 * a valid object.
 * @param xctxt The current execution context.
 * @return A valid XObject.
 *
 * @throws javax.xml.transform.TransformerException
 */
public XObject execute(XPathContext xctxt)
        throws javax.xml.transform.TransformerException
{
  if (xctxt.isSecureProcessing())
    throw new javax.xml.transform.TransformerException(
      XPATHMessages.createXPATHMessage(
        XPATHErrorResources.ER_EXTENSION_FUNCTION_CANNOT_BE_INVOKED,
        new Object[] {toString()}));
    
  XObject result;
  Vector argVec = new Vector();
  int nArgs = m_argVec.size();

  for (int i = 0; i < nArgs; i++)
  {
    Expression arg = (Expression) m_argVec.elementAt(i);
    
    XObject xobj = arg.execute(xctxt);
    /*
     * Should cache the arguments for func:function
     */
    xobj.allowDetachToRelease(false); 
    argVec.addElement(xobj);
  }
  //dml
  ExtensionsProvider extProvider = (ExtensionsProvider)xctxt.getOwnerObject();
  Object val = extProvider.extFunction(this, argVec);

  if (null != val)
  {
    result = XObject.create(val, xctxt);
  }
  else
  {
    result = new XNull();
  }

  return result;
}
 

/**
 * Copy NodeList members into this nodelist, adding in
 * document order.  If a node is null, don't add it.
 *
 * @param iterator DTMIterator which yields the nodes to be added.
 * @param support The XPath runtime context.
 * @throws RuntimeException thrown if this NodeSetDTM is not of 
 * a mutable type.
 */
public void addNodesInDocOrder(DTMIterator iterator, XPathContext support)
{

  if (!m_mutable)
    throw new RuntimeException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_NODESETDTM_NOT_MUTABLE, null)); //"This NodeSetDTM is not mutable!");

  int node;

  while (DTM.NULL != (node = iterator.nextNode()))
  {
    addNodeInDocOrder(node, support);
  }
}
 

/**
 * Append a Node onto the vector.
 *
 * @param value The node to be added.
 * @throws RuntimeException thrown if this NodeSetDTM is not of 
 * a mutable type.
 */
public void addElement(int value)
{

  if (!m_mutable)
    throw new RuntimeException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_NODESETDTM_NOT_MUTABLE, null)); //"This NodeSetDTM is not mutable!");

  super.addElement(value);
}