nodetest.java

java1.6众多例子参考

   * Tell what node type to test, if not DTMFilter.SHOW_ALL.
   *
   * @param whatToShow Bit set defined mainly by 
   *        {@link com.sun.org.apache.xml.internal.dtm.DTMFilter}.
   * @return the node type for the whatToShow.  Since whatToShow can specify 
   *         multiple types, it will return the first bit tested that is on, 
   *         so the caller of this function should take care that this is 
   *         the function they really want to call.  If none of the known bits
   *         are set, this function will return zero.
   */
  public static int getNodeTypeTest(int whatToShow)
  {
    // %REVIEW% Is there a better way?
    if (0 != (whatToShow & DTMFilter.SHOW_ELEMENT))
      return DTM.ELEMENT_NODE;

    if (0 != (whatToShow & DTMFilter.SHOW_ATTRIBUTE))
      return DTM.ATTRIBUTE_NODE;
      
    if (0 != (whatToShow & DTMFilter.SHOW_TEXT))
      return DTM.TEXT_NODE;
      
    if (0 != (whatToShow & DTMFilter.SHOW_DOCUMENT))
      return DTM.DOCUMENT_NODE;

    if (0 != (whatToShow & DTMFilter.SHOW_DOCUMENT_FRAGMENT))
      return DTM.DOCUMENT_FRAGMENT_NODE;

    if (0 != (whatToShow & DTMFilter.SHOW_NAMESPACE))
      return DTM.NAMESPACE_NODE;

    if (0 != (whatToShow & DTMFilter.SHOW_COMMENT))
      return DTM.COMMENT_NODE;

    if (0 != (whatToShow & DTMFilter.SHOW_PROCESSING_INSTRUCTION))
      return DTM.PROCESSING_INSTRUCTION_NODE;

    if (0 != (whatToShow & DTMFilter.SHOW_DOCUMENT_TYPE))
      return DTM.DOCUMENT_TYPE_NODE;

    if (0 != (whatToShow & DTMFilter.SHOW_ENTITY))
      return DTM.ENTITY_NODE;

    if (0 != (whatToShow & DTMFilter.SHOW_ENTITY_REFERENCE))
      return DTM.ENTITY_REFERENCE_NODE;

    if (0 != (whatToShow & DTMFilter.SHOW_NOTATION))
      return DTM.NOTATION_NODE;
      
    if (0 != (whatToShow & DTMFilter.SHOW_CDATA_SECTION))
      return DTM.CDATA_SECTION_NODE;


    return 0;
  }


  /**
   * Do a diagnostics dump of a whatToShow bit set.
   *
   *
   * @param whatToShow Bit set defined mainly by 
   *        {@link com.sun.org.apache.xml.internal.dtm.DTMFilter}.
   */
  public static void debugWhatToShow(int whatToShow)
  {

    java.util.Vector v = new java.util.Vector();

    if (0 != (whatToShow & DTMFilter.SHOW_ATTRIBUTE))
      v.addElement("SHOW_ATTRIBUTE");
      
    if (0 != (whatToShow & DTMFilter.SHOW_NAMESPACE))
      v.addElement("SHOW_NAMESPACE");

    if (0 != (whatToShow & DTMFilter.SHOW_CDATA_SECTION))
      v.addElement("SHOW_CDATA_SECTION");

    if (0 != (whatToShow & DTMFilter.SHOW_COMMENT))
      v.addElement("SHOW_COMMENT");

    if (0 != (whatToShow & DTMFilter.SHOW_DOCUMENT))
      v.addElement("SHOW_DOCUMENT");

    if (0 != (whatToShow & DTMFilter.SHOW_DOCUMENT_FRAGMENT))
      v.addElement("SHOW_DOCUMENT_FRAGMENT");

    if (0 != (whatToShow & DTMFilter.SHOW_DOCUMENT_TYPE))
      v.addElement("SHOW_DOCUMENT_TYPE");

    if (0 != (whatToShow & DTMFilter.SHOW_ELEMENT))
      v.addElement("SHOW_ELEMENT");

    if (0 != (whatToShow & DTMFilter.SHOW_ENTITY))
      v.addElement("SHOW_ENTITY");

    if (0 != (whatToShow & DTMFilter.SHOW_ENTITY_REFERENCE))
      v.addElement("SHOW_ENTITY_REFERENCE");

    if (0 != (whatToShow & DTMFilter.SHOW_NOTATION))
      v.addElement("SHOW_NOTATION");

    if (0 != (whatToShow & DTMFilter.SHOW_PROCESSING_INSTRUCTION))
      v.addElement("SHOW_PROCESSING_INSTRUCTION");

    if (0 != (whatToShow & DTMFilter.SHOW_TEXT))
      v.addElement("SHOW_TEXT");

    int n = v.size();

    for (int i = 0; i < n; i++)
    {
      if (i > 0)
        System.out.print(" | ");

      System.out.print(v.elementAt(i));
    }

    if (0 == n)
      System.out.print("empty whatToShow: " + whatToShow);

    System.out.println();
  }

  /**
   * Two names are equal if they and either both are null or
   * the name t is wild and the name p is non-null, or the two
   * strings are equal.
   *
   * @param p part string from the node.
   * @param t target string, which may be {@link #WILD}.
   *
   * @return true if the strings match according to the rules of this method.
   */
  private static final boolean subPartMatch(String p, String t)
  {

    // boolean b = (p == t) || ((null != p) && ((t == WILD) || p.equals(t)));
    // System.out.println("subPartMatch - p: "+p+", t: "+t+", result: "+b);
    return (p == t) || ((null != p) && ((t == WILD) || p.equals(t)));
  }

  /**
   * This is temporary to patch over Xerces issue with representing DOM
   * namespaces as "".
   *
   * @param p part string from the node, which may represent the null namespace
   *        as null or as "".
   * @param t target string, which may be {@link #WILD}.
   *
   * @return true if the strings match according to the rules of this method.
   */
  private static final boolean subPartMatchNS(String p, String t)
  {

    return (p == t)
           || ((null != p)
               && ((p.length() > 0)
                   ? ((t == WILD) || p.equals(t)) : null == t));
  }

  /**
   * Tell what the test score is for the given node.
   *
   *
   * @param xctxt XPath runtime context.
   * @param context The node being tested.
   *
   * @return {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NODETEST},
   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NONE},
   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NSWILD},
   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_QNAME}, or
   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_OTHER}.
   *
   * @throws javax.xml.transform.TransformerException
   */
  public XObject execute(XPathContext xctxt, int context)
          throws javax.xml.transform.TransformerException
  {

    DTM dtm = xctxt.getDTM(context);
    short nodeType = dtm.getNodeType(context);

    if (m_whatToShow == DTMFilter.SHOW_ALL)
      return m_score;

    int nodeBit = (m_whatToShow & (0x00000001 << (nodeType - 1)));

    switch (nodeBit)
    {
    case DTMFilter.SHOW_DOCUMENT_FRAGMENT :
    case DTMFilter.SHOW_DOCUMENT :
      return SCORE_OTHER;
    case DTMFilter.SHOW_COMMENT :
      return m_score;
    case DTMFilter.SHOW_CDATA_SECTION :
    case DTMFilter.SHOW_TEXT :

      // was: 
      // return (!xctxt.getDOMHelper().shouldStripSourceNode(context))
      //       ? m_score : SCORE_NONE;
      return m_score;
    case DTMFilter.SHOW_PROCESSING_INSTRUCTION :
      return subPartMatch(dtm.getNodeName(context), m_name)
             ? m_score : SCORE_NONE;

    // From the draft: "Two expanded names are equal if they 
    // have the same local part, and either both have no URI or 
    // both have the same URI."
    // "A node test * is true for any node of the principal node type. 
    // For example, child::* will select all element children of the 
    // context node, and attribute::* will select all attributes of 
    // the context node."
    // "A node test can have the form NCName:*. In this case, the prefix 
    // is expanded in the same way as with a QName using the context 
    // namespace declarations. The node test will be true for any node 
    // of the principal type whose expanded name has the URI to which 
    // the prefix expands, regardless of the local part of the name."
    case DTMFilter.SHOW_NAMESPACE :
    {
      String ns = dtm.getLocalName(context);

      return (subPartMatch(ns, m_name)) ? m_score : SCORE_NONE;
    }
    case DTMFilter.SHOW_ATTRIBUTE :
    case DTMFilter.SHOW_ELEMENT :
    {
      return (m_isTotallyWild || (subPartMatchNS(dtm.getNamespaceURI(context), m_namespace) && subPartMatch(dtm.getLocalName(context), m_name)))
             ? m_score : SCORE_NONE;
    }
    default :
      return SCORE_NONE;
    }  // end switch(testType)
  }
  
  /**
   * Tell what the test score is for the given node.
   *
   *
   * @param xctxt XPath runtime context.
   * @param context The node being tested.
   *
   * @return {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NODETEST},
   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NONE},
   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NSWILD},
   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_QNAME}, or
   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_OTHER}.
   *
   * @throws javax.xml.transform.TransformerException
   */
  public XObject execute(XPathContext xctxt, int context, 
                         DTM dtm, int expType)
          throws javax.xml.transform.TransformerException
  {

    if (m_whatToShow == DTMFilter.SHOW_ALL)
      return m_score;

    int nodeBit = (m_whatToShow & (0x00000001 
                   << ((dtm.getNodeType(context)) - 1)));

    switch (nodeBit)
    {
    case DTMFilter.SHOW_DOCUMENT_FRAGMENT :
    case DTMFilter.SHOW_DOCUMENT :
      return SCORE_OTHER;
    case DTMFilter.SHOW_COMMENT :
      return m_score;
    case DTMFilter.SHOW_CDATA_SECTION :
    case DTMFilter.SHOW_TEXT :

      // was: 
      // return (!xctxt.getDOMHelper().shouldStripSourceNode(context))
      //       ? m_score : SCORE_NONE;
      return m_score;
    case DTMFilter.SHOW_PROCESSING_INSTRUCTION :
      return subPartMatch(dtm.getNodeName(context), m_name)
             ? m_score : SCORE_NONE;

    // From the draft: "Two expanded names are equal if they 
    // have the same local part, and either both have no URI or 
    // both have the same URI."
    // "A node test * is true for any node of the principal node type. 
    // For example, child::* will select all element children of the 
    // context node, and attribute::* will select all attributes of 
    // the context node."
    // "A node test can have the form NCName:*. In this case, the prefix 
    // is expanded in the same way as with a QName using the context 
    // namespace declarations. The node test will be true for any node 
    // of the principal type whose expanded name has the URI to which 
    // the prefix expands, regardless of the local part of the name."
    case DTMFilter.SHOW_NAMESPACE :
    {
      String ns = dtm.getLocalName(context);

      return (subPartMatch(ns, m_name)) ? m_score : SCORE_NONE;
    }
    case DTMFilter.SHOW_ATTRIBUTE :
    case DTMFilter.SHOW_ELEMENT :
    {
      return (m_isTotallyWild || (subPartMatchNS(dtm.getNamespaceURI(context), m_namespace) && subPartMatch(dtm.getLocalName(context), m_name)))
             ? m_score : SCORE_NONE;
    }
    default :
      return SCORE_NONE;
    }  // end switch(testType)
  }

  /**
   * Test the current node to see if it matches the given node test.
   *
   * @param xctxt XPath runtime context.
   *
   * @return {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NODETEST},
   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NONE},
   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_NSWILD},
   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_QNAME}, or
   *         {@link com.sun.org.apache.xpath.internal.patterns.NodeTest#SCORE_OTHER}.
   *
   * @throws javax.xml.transform.TransformerException
   */
  public XObject execute(XPathContext xctxt)
          throws javax.xml.transform.TransformerException
  {
    return execute(xctxt, xctxt.getCurrentNode());
  }
  
  /**
   * Node tests by themselves do not need to fix up variables.
   */
  public void fixupVariables(java.util.Vector vars, int globalsSize)
  {
    // no-op
  }

  /**
   * @see com.sun.org.apache.xpath.internal.XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)
   */
  public void callVisitors(ExpressionOwner owner, XPathVisitor visitor)
  {
  	assertion(false, "callVisitors should not be called for this object!!!");  	
  }

}