https://openjdk.java.net/ 
/*
 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
 */
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

package com.sun.org.apache.xpath.internal.objects;

import com.sun.org.apache.xalan.internal.res.XSLMessages;
import com.sun.org.apache.xml.internal.dtm.DTM;
import com.sun.org.apache.xml.internal.dtm.DTMIterator;
import com.sun.org.apache.xml.internal.utils.QName;
import com.sun.org.apache.xml.internal.utils.XMLString;
import com.sun.org.apache.xpath.internal.Expression;
import com.sun.org.apache.xpath.internal.ExpressionOwner;
import com.sun.org.apache.xpath.internal.NodeSetDTM;
import com.sun.org.apache.xpath.internal.XPathContext;
import com.sun.org.apache.xpath.internal.XPathException;
import com.sun.org.apache.xpath.internal.XPathVisitor;
import com.sun.org.apache.xpath.internal.res.XPATHErrorResources;
import java.io.Serializable;
import java.util.List;
import org.w3c.dom.DocumentFragment;
import org.w3c.dom.NodeList;
import org.w3c.dom.traversal.NodeIterator;


This class represents an XPath object, and is capable of
converting the object to various types, such as a string.
This class acts as the base class to other XPath type objects,
such as XString, and provides polymorphic casting capabilities.

@xsl.usagegeneral
@LastModified: Oct 2017
/**
 * This class represents an XPath object, and is capable of
 * converting the object to various types, such as a string.
 * This class acts as the base class to other XPath type objects,
 * such as XString, and provides polymorphic casting capabilities.
 * @xsl.usage general
 * @LastModified: Oct 2017
 */
public class XObject extends Expression implements Serializable, Cloneable
{
    static final long serialVersionUID = -821887098985662951L;

  
The java object which this object wraps.
 @serial

/**
   * The java object which this object wraps.
   *  @serial
   */
  protected Object m_obj;  // This may be NULL!!!

  
Create an XObject.

/**
   * Create an XObject.
   */
  public XObject(){}

  
Create an XObject.

Params:
  • obj – Can be any object, should be a specific type
for derived classes, or null.
/**
   * Create an XObject.
   *
   * @param obj Can be any object, should be a specific type
   * for derived classes, or null.
   */
  public XObject(Object obj)
  {
    setObject(obj);
  }

  protected void setObject(Object obj) {
      m_obj = obj;
  }

  
For support of literal objects in xpaths.

Params:
  • xctxt – The XPath execution context.
Throws:
Returns:This object.
/**
   * For support of literal objects in xpaths.
   *
   * @param xctxt The XPath execution context.
   *
   * @return This object.
   *
   * @throws javax.xml.transform.TransformerException
   */
  public XObject execute(XPathContext xctxt)
          throws javax.xml.transform.TransformerException
  {
    return this;
  }

  
Specify if it's OK for detach to release the iterator for reuse.
This function should be called with a value of false for objects that are
stored in variables.
Calling this with a value of false on a XNodeSet will cause the nodeset
to be cached.

Params:
  • allowRelease – true if it is OK for detach to release this iterator
for pooling.
/**
   * Specify if it's OK for detach to release the iterator for reuse.
   * This function should be called with a value of false for objects that are
   * stored in variables.
   * Calling this with a value of false on a XNodeSet will cause the nodeset
   * to be cached.
   *
   * @param allowRelease true if it is OK for detach to release this iterator
   * for pooling.
   */
  public void allowDetachToRelease(boolean allowRelease){}

  
Detaches the DTMIterator from the set which it iterated
over, releasing any computational resources and placing the iterator
in the INVALID state. After detach has been invoked,
calls to nextNode or previousNode will
raise a runtime exception.

/**
   * Detaches the <code>DTMIterator</code> from the set which it iterated
   * over, releasing any computational resources and placing the iterator
   * in the INVALID state. After <code>detach</code> has been invoked,
   * calls to <code>nextNode</code> or <code>previousNode</code> will
   * raise a runtime exception.
   */
  public void detach(){}

  
Forces the object to release it's resources.  This is more harsh than
detach().

/**
   * Forces the object to release it's resources.  This is more harsh than
   * detach().
   */
  public void destruct()
  {

    if (null != m_obj)
    {
      allowDetachToRelease(true);
      detach();

      setObject(null);
    }
  }

  
Reset for fresh reuse.

/**
   * Reset for fresh reuse.
   */
  public void reset()
  {
  }

  
Directly call the
characters method on the passed ContentHandler for the
string-value. Multiple calls to the
ContentHandler's characters methods may well occur for a single call to
this method.

Params:
  • ch – A non-null reference to a ContentHandler.
Throws:
/**
   * Directly call the
   * characters method on the passed ContentHandler for the
   * string-value. Multiple calls to the
   * ContentHandler's characters methods may well occur for a single call to
   * this method.
   *
   * @param ch A non-null reference to a ContentHandler.
   *
   * @throws org.xml.sax.SAXException
   */
  public void dispatchCharactersEvents(org.xml.sax.ContentHandler ch)
          throws org.xml.sax.SAXException
  {
    xstr().dispatchCharactersEvents(ch);
  }

  
Create the right XObject based on the type of the object passed.  This
function can not make an XObject that exposes DOM Nodes, NodeLists, and
NodeIterators to the XSLT stylesheet as node-sets.

Params:
  • val – The java object which this object will wrap.
Returns:the right XObject based on the type of the object passed.
/**
   * Create the right XObject based on the type of the object passed.  This
   * function can not make an XObject that exposes DOM Nodes, NodeLists, and
   * NodeIterators to the XSLT stylesheet as node-sets.
   *
   * @param val The java object which this object will wrap.
   *
   * @return the right XObject based on the type of the object passed.
   */
  static public XObject create(Object val)
  {
    return XObjectFactory.create(val);
  }

  
Create the right XObject based on the type of the object passed.
This function can make an XObject that exposes DOM Nodes, NodeLists, and
NodeIterators to the XSLT stylesheet as node-sets.

Params:
  • val – The java object which this object will wrap.
  • xctxt – The XPath context.
Returns:the right XObject based on the type of the object passed.
/**
   * Create the right XObject based on the type of the object passed.
   * This function <emph>can</emph> make an XObject that exposes DOM Nodes, NodeLists, and
   * NodeIterators to the XSLT stylesheet as node-sets.
   *
   * @param val The java object which this object will wrap.
   * @param xctxt The XPath context.
   *
   * @return the right XObject based on the type of the object passed.
   */
  static public XObject create(Object val, XPathContext xctxt)
  {
    return XObjectFactory.create(val, xctxt);
  }

  
Constant for NULL object type 
/** Constant for NULL object type */
  public static final int CLASS_NULL = -1;

  
Constant for UNKNOWN object type 
/** Constant for UNKNOWN object type */
  public static final int CLASS_UNKNOWN = 0;

  
Constant for BOOLEAN  object type 
/** Constant for BOOLEAN  object type */
  public static final int CLASS_BOOLEAN = 1;

  
Constant for NUMBER object type 
/** Constant for NUMBER object type */
  public static final int CLASS_NUMBER = 2;

  
Constant for STRING object type 
/** Constant for STRING object type */
  public static final int CLASS_STRING = 3;

  
Constant for NODESET object type 
/** Constant for NODESET object type */
  public static final int CLASS_NODESET = 4;

  
Constant for RESULT TREE FRAGMENT object type 
/** Constant for RESULT TREE FRAGMENT object type */
  public static final int CLASS_RTREEFRAG = 5;

  
Represents an unresolved variable type as an integer. 
/** Represents an unresolved variable type as an integer. */
  public static final int CLASS_UNRESOLVEDVARIABLE = 600;

  
Tell what kind of class this is.

Returns:CLASS_UNKNOWN
/**
   * Tell what kind of class this is.
   *
   * @return CLASS_UNKNOWN
   */
  public int getType()
  {
    return CLASS_UNKNOWN;
  }

  
Given a request type, return the equivalent string.
For diagnostic purposes.

Returns:type string "#UNKNOWN" + object class name
/**
   * Given a request type, return the equivalent string.
   * For diagnostic purposes.
   *
   * @return type string "#UNKNOWN" + object class name
   */
  public String getTypeString()
  {
    return "#UNKNOWN (" + object().getClass().getName() + ")";
  }

  
Cast result object to a number. Always issues an error.

Throws:
Returns:0.0
/**
   * 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 number, but allow side effects, such as the
incrementing of an iterator.

Returns:numeric value of the string conversion from the
next node in the NodeSetDTM, or NAN if no node was found
/**
   * Cast result object to a number, but allow side effects, such as the
   * incrementing of an iterator.
   *
   * @return numeric value of the string conversion from the
   * next node in the NodeSetDTM, or NAN if no node was found
   */
  public double numWithSideEffects()  throws javax.xml.transform.TransformerException
  {
    return num();
  }

  
Cast result object to a boolean. Always issues an error.

Throws:
Returns:false
/**
   * 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 boolean, but allow side effects, such as the
incrementing of an iterator.

Returns:True if there is a next node in the nodeset
/**
   * Cast result object to a boolean, but allow side effects, such as the
   * incrementing of an iterator.
   *
   * @return True if there is a next node in the nodeset
   */
  public boolean boolWithSideEffects() throws javax.xml.transform.TransformerException
  {
    return bool();
  }


  
Cast result object to a string.

Returns:The string this wraps or the empty string if null
/**
   * Cast result object to a string.
   *
   * @return The string this wraps or the empty string if null
   */
  public XMLString xstr()
  {
    return XMLStringFactoryImpl.getFactory().newstr(str());
  }

  
Cast result object to a string.

Returns:The object as a string
/**
   * Cast result object to a string.
   *
   * @return The object as a string
   */
  public String str()
  {
    return (m_obj != null) ? m_obj.toString() : "";
  }

  
Return the string representation of the object

Returns:the string representation of the object
/**
   * Return the string representation of the object
   *
   *
   * @return the string representation of the object
   */
  public String toString()
  {
    return str();
  }

  
Cast result object to a result tree fragment.

Params:
  • support – XPath context to use for the conversion
Returns:the objec as a result tree fragment.
/**
   * Cast result object to a result tree fragment.
   *
   * @param support XPath context to use for the conversion
   *
   * @return the objec as a result tree fragment.
   */
  public int rtf(XPathContext support)
  {

    int result = rtf();

    if (DTM.NULL == result)
    {
      DTM frag = support.createDocumentFragment();

      // %OPT%
      frag.appendTextChild(str());

      result = frag.getDocument();
    }

    return result;
  }

  
Cast result object to a result tree fragment.

Params:
  • support – XPath context to use for the conversion
Returns:the objec as a result tree fragment.
/**
   * Cast result object to a result tree fragment.
   *
   * @param support XPath context to use for the conversion
   *
   * @return the objec as a result tree fragment.
   */
  public DocumentFragment rtree(XPathContext support)
  {
    DocumentFragment docFrag = null;
    int result = rtf();

    if (DTM.NULL == result)
    {
      DTM frag = support.createDocumentFragment();

      // %OPT%
      frag.appendTextChild(str());

      docFrag = (DocumentFragment)frag.getNode(frag.getDocument());
    }
    else
    {
      DTM frag = support.getDTM(result);
      docFrag = (DocumentFragment)frag.getNode(frag.getDocument());
    }

    return docFrag;
  }


  
For functions to override.

Returns:null
/**
   * For functions to override.
   *
   * @return null
   */
  public DocumentFragment rtree()
  {
    return null;
  }

  
For functions to override.

Returns:null
/**
   * For functions to override.
   *
   * @return null
   */
  public int rtf()
  {
    return DTM.NULL;
  }

  
Return a java object that's closest to the representation
that should be handed to an extension.

Returns:The object that this class wraps
/**
   * Return a java object that's closest to the representation
   * that should be handed to an extension.
   *
   * @return The object that this class wraps
   */
  public Object object()
  {
    return m_obj;
  }

  
Cast result object to a nodelist. Always issues an error.

Throws:
Returns:null
/**
   * 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;
  }

  
Get a fresh copy of the object.  For use with variables.

Returns:This object, unless overridden by subclass.
/**
   * Get a fresh copy of the object.  For use with variables.
   *
   * @return This object, unless overridden by subclass.
   */
  public XObject getFresh()
  {
    return this;
  }


  
Cast result object to a nodelist. Always issues an error.

Throws:
Returns: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.

Throws:
Returns: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.

Throws:
Returns:The object as a NodeSetDTM.
/**
   * 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;
  }

  
Cast object to type t.

Params:
  • t – Type of object to cast this to
  • support – XPath context to use for the conversion
Throws:
Returns:This object as the given type t
/**
   * Cast object to type t.
   *
   * @param t Type of object to cast this to
   * @param support XPath context to use for the conversion
   *
   * @return This object as the given type t
   *
   * @throws javax.xml.transform.TransformerException
   */
  public Object castToType(int t, XPathContext support)
          throws javax.xml.transform.TransformerException
  {

    Object result;

    switch (t)
    {
    case CLASS_STRING :
      result = str();
      break;
    case CLASS_NUMBER :
      result = num();
      break;
    case CLASS_NODESET :
      result = iter();
      break;
    case CLASS_BOOLEAN :
      result = bool();
      break;
    case CLASS_UNKNOWN :
      result = m_obj;
      break;

    // %TBD%  What to do here?
    //    case CLASS_RTREEFRAG :
    //      result = rtree(support);
    //      break;
    default :
      error(XPATHErrorResources.ER_CANT_CONVERT_TO_TYPE,
            new Object[]{ getTypeString(),
                          Integer.toString(t) });  //"Can not convert "+getTypeString()+" to a type#"+t);

      result = null;
    }

    return result;
  }

  
Tell if one object is less than the other.

Params:
  • obj2 – Object to compare this to
Throws:
Returns:True if this object is less than the given object
/**
   * Tell if one object is less than the other.
   *
   * @param obj2 Object to compare this to
   *
   * @return True if this object is less than the given object
   *
   * @throws javax.xml.transform.TransformerException
   */
  public boolean lessThan(XObject obj2)
          throws javax.xml.transform.TransformerException
  {

    // In order to handle the 'all' semantics of
    // nodeset comparisons, we always call the
    // nodeset function.  Because the arguments
    // are backwards, we call the opposite comparison
    // function.
    if (obj2.getType() == XObject.CLASS_NODESET)
      return obj2.greaterThan(this);

    return this.num() < obj2.num();
  }

  
Tell if one object is less than or equal to the other.

Params:
  • obj2 – Object to compare this to
Throws:
Returns:True if this object is less than or equal to the given object
/**
   * Tell if one object is less than or equal to the other.
   *
   * @param obj2 Object to compare this to
   *
   * @return True if this object is less than or equal to the given object
   *
   * @throws javax.xml.transform.TransformerException
   */
  public boolean lessThanOrEqual(XObject obj2)
          throws javax.xml.transform.TransformerException
  {

    // In order to handle the 'all' semantics of
    // nodeset comparisons, we always call the
    // nodeset function.  Because the arguments
    // are backwards, we call the opposite comparison
    // function.
    if (obj2.getType() == XObject.CLASS_NODESET)
      return obj2.greaterThanOrEqual(this);

    return this.num() <= obj2.num();
  }

  
Tell if one object is greater than the other.

Params:
  • obj2 – Object to compare this to
Throws:
Returns:True if this object is greater than the given object
/**
   * Tell if one object is greater than the other.
   *
   * @param obj2 Object to compare this to
   *
   * @return True if this object is greater than the given object
   *
   * @throws javax.xml.transform.TransformerException
   */
  public boolean greaterThan(XObject obj2)
          throws javax.xml.transform.TransformerException
  {

    // In order to handle the 'all' semantics of
    // nodeset comparisons, we always call the
    // nodeset function.  Because the arguments
    // are backwards, we call the opposite comparison
    // function.
    if (obj2.getType() == XObject.CLASS_NODESET)
      return obj2.lessThan(this);

    return this.num() > obj2.num();
  }

  
Tell if one object is greater than or equal to the other.

Params:
  • obj2 – Object to compare this to
Throws:
Returns:True if this object is greater than or equal to the given object
/**
   * Tell if one object is greater than or equal to the other.
   *
   * @param obj2 Object to compare this to
   *
   * @return True if this object is greater than or equal to the given object
   *
   * @throws javax.xml.transform.TransformerException
   */
  public boolean greaterThanOrEqual(XObject obj2)
          throws javax.xml.transform.TransformerException
  {

    // In order to handle the 'all' semantics of
    // nodeset comparisons, we always call the
    // nodeset function.  Because the arguments
    // are backwards, we call the opposite comparison
    // function.
    if (obj2.getType() == XObject.CLASS_NODESET)
      return obj2.lessThanOrEqual(this);

    return this.num() >= obj2.num();
  }

  
Tell if two objects are functionally equal.

Params:
  • obj2 – Object to compare this to
Throws:
Returns:True if this object is equal to the given object
/**
   * Tell if two objects are functionally equal.
   *
   * @param obj2 Object to compare this to
   *
   * @return True if this object is equal to the given object
   *
   * @throws javax.xml.transform.TransformerException
   */
  public boolean equals(XObject obj2)
  {

    // In order to handle the 'all' semantics of
    // nodeset comparisons, we always call the
    // nodeset function.
    if (obj2.getType() == XObject.CLASS_NODESET)
      return obj2.equals(this);

    if (null != m_obj)
    {
      return m_obj.equals(obj2.m_obj);
    }
    else
    {
      return obj2.m_obj == null;
    }
  }

  
Tell if two objects are functionally not equal.

Params:
  • obj2 – Object to compare this to
Throws:
Returns:True if this object is not equal to the given object
/**
   * Tell if two objects are functionally not equal.
   *
   * @param obj2 Object to compare this to
   *
   * @return True if this object is not equal to the given object
   *
   * @throws javax.xml.transform.TransformerException
   */
  public boolean notEquals(XObject obj2)
          throws javax.xml.transform.TransformerException
  {

    // In order to handle the 'all' semantics of
    // nodeset comparisons, we always call the
    // nodeset function.
    if (obj2.getType() == XObject.CLASS_NODESET)
      return obj2.notEquals(this);

    return !equals(obj2);
  }

  
Tell the user of an error, and probably throw an
exception.

Params:
  • msg – Error message to issue
Throws:
/**
   * Tell the user of an error, and probably throw an
   * exception.
   *
   * @param msg Error message to issue
   *
   * @throws javax.xml.transform.TransformerException
   */
  protected void error(String msg)
          throws javax.xml.transform.TransformerException
  {
    error(msg, null);
  }

  
Tell the user of an error, and probably throw an
exception.

Params:
  • msg – Error message to issue
  • args – Arguments to use in the message
Throws:
/**
   * Tell the user of an error, and probably throw an
   * exception.
   *
   * @param msg Error message to issue
   * @param args Arguments to use in the message
   *
   * @throws javax.xml.transform.TransformerException
   */
  protected void error(String msg, Object[] args)
          throws javax.xml.transform.TransformerException
  {

    String fmsg = XSLMessages.createXPATHMessage(msg, args);

    // boolean shouldThrow = support.problem(m_support.XPATHPROCESSOR,
    //                                      m_support.ERROR,
    //                                      null,
    //                                      null, fmsg, 0, 0);
    // if(shouldThrow)
    {
      throw new XPathException(fmsg, this);
    }
  }


  
XObjects should not normally need to fix up variables.

/**
   * XObjects should not normally need to fix up variables.
   */
  public void fixupVariables(List<QName> vars, int globalsSize)
  {
    // no-op
  }


  
Cast result object to a string.
NEEDSDOC @param fsb

Returns:The string this wraps or the empty string if null
/**
   * Cast result object to a string.
   *
   *
   * NEEDSDOC @param fsb
   * @return The string this wraps or the empty string if null
   */
  public void appendToFsb(com.sun.org.apache.xml.internal.utils.FastStringBuffer fsb)
  {
    fsb.append(str());
  }

  
See Also:
  • callVisitors.callVisitors(ExpressionOwner, XPathVisitor)
/**
   * @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!!!");
  }
  
See Also:
  • deepEquals.deepEquals(Expression)
/**
   * @see Expression#deepEquals(Expression)
   */
  public boolean deepEquals(Expression expr)
  {
        if(!isSameClass(expr))
                return false;

        // If equals at the expression level calls deepEquals, I think we're
        // still safe from infinite recursion since this object overrides
        // equals.  I hope.
        if(!this.equals((XObject)expr))
                return false;

        return true;
  }

}