xstringforfsb.java

java1.6众多例子参考

/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed 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.
 */
/*
 * $Id: XStringForFSB.java,v 1.2.4.2 2005/09/14 20:46:27 jeffsuttor Exp $
 */
package com.sun.org.apache.xpath.internal.objects;

import com.sun.org.apache.xalan.internal.res.XSLMessages;
import com.sun.org.apache.xml.internal.utils.FastStringBuffer;
import com.sun.org.apache.xml.internal.utils.XMLCharacterRecognizer;
import com.sun.org.apache.xml.internal.utils.XMLString;
import com.sun.org.apache.xml.internal.utils.XMLStringFactory;
import com.sun.org.apache.xpath.internal.res.XPATHErrorResources;

/**
 * This class will wrap a FastStringBuffer and allow for
 */
public class XStringForFSB extends XString
{
    static final long serialVersionUID = -1533039186550674548L;

  /** The start position in the fsb. */
  int m_start;

  /** The length of the string. */
  int m_length;

  /** If the str() function is called, the string will be cached here. */
  protected String m_strCache = null;

  /** cached hash code */
  protected int m_hash = 0;

  /**
   * 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 string.
   *
   * @return The string this wraps or the empty string if null
   */
  public FastStringBuffer fsb()
  {
    return ((FastStringBuffer) m_obj);
  }
  
  /**
   * Cast result object to a string.
   *
   * @return The string this wraps or the empty string if null
   */
  public void appendToFsb(com.sun.org.apache.xml.internal.utils.FastStringBuffer fsb)
  {
    // %OPT% !!! FSB has to be updated to take partial fsb's for append.
    fsb.append(str());
  }

  /**
   * Tell if this object contains a java String object.
   *
   * @return true if this XMLString can return a string without creating one.
   */
  public boolean hasString()
  {
    return (null != m_strCache);
  }

//  /** NEEDSDOC Field strCount */
//  public static int strCount = 0;
//
//  /** NEEDSDOC Field xtable */
//  static java.util.Hashtable xtable = new java.util.Hashtable();

  /**
   * Since this object is incomplete without the length and the offset, we 
   * have to convert to a string when this function is called.
   *
   * @return The java String representation of this object.
   */
  public Object object()
  {
    return str();
  }

  /**
   * Cast result object to a string.
   *
   * @return The string this wraps or the empty string if null
   */
  public String str()
  {

    if (null == m_strCache)
    {
      m_strCache = fsb().getString(m_start, m_length);

//      strCount++;
//
//      RuntimeException e = new RuntimeException("Bad!  Bad!");
//      java.io.CharArrayWriter writer = new java.io.CharArrayWriter();
//      java.io.PrintWriter pw = new java.io.PrintWriter(writer);
//
//      e.printStackTrace(pw);
//
//      String str = writer.toString();
//
//      str = str.substring(0, 600);
//
//      if (null == xtable.get(str))
//      {
//        xtable.put(str, str);
//        System.out.println(str);
//      }
//      System.out.println("strCount: " + strCount);

//      throw e;
//      e.printStackTrace();
      // System.exit(-1);
    }

    return m_strCache;
  }

  /**
   * 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
  {
    fsb().sendSAXcharacters(ch, m_start, m_length);
  }

  /**
   * Directly call the
   * comment method on the passed LexicalHandler for the
   * string-value.
   *
   * @param lh A non-null reference to a LexicalHandler.
   *
   * @throws org.xml.sax.SAXException
   */
  public void dispatchAsComment(org.xml.sax.ext.LexicalHandler lh)
          throws org.xml.sax.SAXException
  {
    fsb().sendSAXComment(lh, m_start, m_length);
  }

  /**
   * Returns the length of this string.
   *
   * @return  the length of the sequence of characters represented by this
   *          object.
   */
  public int length()
  {
    return m_length;
  }

  /**
   * Returns the character at the specified index. An index ranges
   * from <code>0</code> to <code>length() - 1</code>. The first character
   * of the sequence is at index <code>0</code>, the next at index
   * <code>1</code>, and so on, as for array indexing.
   *
   * @param      index   the index of the character.
   * @return     the character at the specified index of this string.
   *             The first character is at index <code>0</code>.
   * @exception  IndexOutOfBoundsException  if the <code>index</code>
   *             argument is negative or not less than the length of this
   *             string.
   */
  public char charAt(int index)
  {
    return fsb().charAt(m_start + index);
  }

  /**
   * Copies characters from this string into the destination character
   * array.
   *
   * @param      srcBegin   index of the first character in the string
   *                        to copy.
   * @param      srcEnd     index after the last character in the string
   *                        to copy.
   * @param      dst        the destination array.
   * @param      dstBegin   the start offset in the destination array.
   * @exception IndexOutOfBoundsException If any of the following
   *            is true:
   *            <ul><li><code>srcBegin</code> is negative.
   *            <li><code>srcBegin</code> is greater than <code>srcEnd</code>
   *            <li><code>srcEnd</code> is greater than the length of this
   *                string
   *            <li><code>dstBegin</code> is negative
   *            <li><code>dstBegin+(srcEnd-srcBegin)</code> is larger than
   *                <code>dst.length</code></ul>
   * @exception NullPointerException if <code>dst</code> is <code>null</code>
   */
  public void getChars(int srcBegin, int srcEnd, char dst[], int dstBegin)
  {

    // %OPT% Need to call this on FSB when it is implemented.
    // %UNTESTED% (I don't think anyone calls this yet?)
    int n = srcEnd - srcBegin;

    if (n > m_length)
      n = m_length;

    if (n > (dst.length - dstBegin))
      n = (dst.length - dstBegin);

    int end = srcBegin + m_start + n;
    int d = dstBegin;
    FastStringBuffer fsb = fsb();

    for (int i = srcBegin + m_start; i < end; i++)
    {
      dst[d++] = fsb.charAt(i);
    }
  }

  /**
   * Compares this string to the specified object.
   * The result is <code>true</code> if and only if the argument is not
   * <code>null</code> and is a <code>String</code> object that represents
   * the same sequence of characters as this object.
   *
   * @param   obj2       the object to compare this <code>String</code>
   *                     against.
   *
   * @return  <code>true</code> if the <code>String </code>are equal;
   *          <code>false</code> otherwise.
   * @see     java.lang.String#compareTo(java.lang.String)
   * @see     java.lang.String#equalsIgnoreCase(java.lang.String)
   */
  public boolean equals(XMLString obj2)
  {

    if (this == obj2)
    {
      return true;
    }

    int n = m_length;

    if (n == obj2.length())
    {
      FastStringBuffer fsb = fsb();
      int i = m_start;
      int j = 0;

      while (n-- != 0)
      {
        if (fsb.charAt(i) != obj2.charAt(j))
        {
          return false;
        }

        i++;
        j++;
      }

      return true;
    }

    return false;
  }

  /**
   * Tell if two objects are functionally equal.
   *
   * @param obj2 Object to compare this to
   *
   * @return true if the two objects are equal
   *
   * @throws javax.xml.transform.TransformerException
   */
  public boolean equals(XObject obj2)
  {

    if (this == obj2)
    {
      return true;
    }
    if(obj2.getType() == XObject.CLASS_NUMBER)
    	return obj2.equals(this);

    String str = obj2.str();
    int n = m_length;

    if (n == str.length())
    {
      FastStringBuffer fsb = fsb();
      int i = m_start;
      int j = 0;

      while (n-- != 0)
      {
        if (fsb.charAt(i) != str.charAt(j))
        {
          return false;
        }

        i++;
        j++;
      }

      return true;
    }

    return false;
  }

  /**
   * Tell if two objects are functionally equal.
   *
   * @param anotherString Object to compare this to
   *
   * @return true if the two objects are equal
   *
   * @throws javax.xml.transform.TransformerException
   */
  public boolean equals(String anotherString)
  {

    int n = m_length;

    if (n == anotherString.length())
    {
      FastStringBuffer fsb = fsb();
      int i = m_start;
      int j = 0;

      while (n-- != 0)
      {
        if (fsb.charAt(i) != anotherString.charAt(j))
        {
          return false;
        }

        i++;
        j++;
      }

      return true;
    }

    return false;
  }

  /**
   * Compares this string to the specified object.
   * The result is <code>true</code> if and only if the argument is not
   * <code>null</code> and is a <code>String</code> object that represents
   * the same sequence of characters as this object.
   *
   * @param   obj2       the object to compare this <code>String</code>
   *                     against.
   *
   * @return  <code>true</code> if the <code>String </code>are equal;
   *          <code>false</code> otherwise.
   * @see     java.lang.String#compareTo(java.lang.String)
   * @see     java.lang.String#equalsIgnoreCase(java.lang.String)
   */
  public boolean equals(Object obj2)
  {

    if (null == obj2)
      return false;
      
    if(obj2 instanceof XNumber)
    	return obj2.equals(this);

      // In order to handle the 'all' semantics of 
      // nodeset comparisons, we always call the 
      // nodeset function.
    else if (obj2 instanceof XNodeSet)
      return obj2.equals(this);
    else if (obj2 instanceof XStringForFSB)
      return equals((XMLString) obj2);
    else
      return equals(obj2.toString());
  }

  /**
   * Compares this <code>String</code> to another <code>String</code>,
   * ignoring case considerations.  Two strings are considered equal
   * ignoring case if they are of the same length, and corresponding
   * characters in the two strings are equal ignoring case.
   *
   * @param   anotherString   the <code>String</code> to compare this
   *                          <code>String</code> against.
   * @return  <code>true</code> if the argument is not <code>null</code>
   *          and the <code>String</code>s are equal,
   *          ignoring case; <code>false</code> otherwise.
   * @see     #equals(Object)
   * @see     java.lang.Character#toLowerCase(char)
   * @see java.lang.Character#toUpperCase(char)
   */
  public boolean equalsIgnoreCase(String anotherString)
  {
    return (m_length == anotherString.length())
           ? str().equalsIgnoreCase(anotherString) : false;
  }

  /**
   * Compares two strings lexicographically.
   *
   * @param   xstr   the <code>String</code> to be compared.
   *
   * @return  the value <code>0</code> if the argument string is equal to
   *          this string; a value less than <code>0</code> if this string
   *          is lexicographically less than the string argument; and a
   *          value greater than <code>0</code> if this string is
   *          lexicographically greater than the string argument.
   * @exception java.lang.NullPointerException if <code>anotherString</code>
   *          is <code>null</code>.
   */
  public int compareTo(XMLString xstr)
  {

    int len1 = m_length;
    int len2 = xstr.length();
    int n = Math.min(len1, len2);
    FastStringBuffer fsb = fsb();
    int i = m_start;
    int j = 0;

    while (n-- != 0)
    {
      char c1 = fsb.charAt(i);
      char c2 = xstr.charAt(j);

      if (c1 != c2)
      {
        return c1 - c2;
      }

      i++;
      j++;
    }