xstringforfsb.java

来自「java jdk 1.4的源码」· Java 代码 · 共 1,081 行 · 第 1/3 页

   * 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 obj2 Object to compare this to
   *
   * NEEDSDOC @param anotherString
   *
   * @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   anObject   the object to compare this <code>String</code>
   *                     against.
   *
   * NEEDSDOC @param obj2
   * @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) this);
    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   anotherString   the <code>String</code> to be compared.
   *
   * NEEDSDOC @param xstr
   * @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++;
    }

    return len1 - len2;
  }

  /**
   * Compares two strings lexicographically, ignoring case considerations.
   * This method returns an integer whose sign is that of
   * <code>this.toUpperCase().toLowerCase().compareTo(
   * str.toUpperCase().toLowerCase())</code>.
   * <p>
   * Note that this method does <em>not</em> take locale into account,
   * and will result in an unsatisfactory ordering for certain locales.
   * The java.text package provides <em>collators</em> to allow
   * locale-sensitive ordering.
   *
   * @param   str   the <code>String</code> to be compared.
   *
   * NEEDSDOC @param xstr
   * @return  a negative integer, zero, or a positive integer as the
   *          the specified String is greater than, equal to, or less
   *          than this String, ignoring case considerations.
   * @see     java.text.Collator#compare(String, String)
   * @since   1.2
   */
  public int compareToIgnoreCase(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 = Character.toLowerCase(fsb.charAt(i));
      char c2 = Character.toLowerCase(xstr.charAt(j));

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

      i++;
      j++;
    }

    return len1 - len2;
  }

  /**
   * Returns a hashcode for this string. The hashcode for a
   * <code>String</code> object is computed as
   * <blockquote><pre>
   * s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1]
   * </pre></blockquote>
   * using <code>int</code> arithmetic, where <code>s[i]</code> is the
   * <i>i</i>th character of the string, <code>n</code> is the length of
   * the string, and <code>^</code> indicates exponentiation.
   * (The hash value of the empty string is zero.)
   *
   * @return  a hash code value for this object.
   */
  public int hashCode()
  {
    // Commenting this out because in JDK1.1.8 and VJ++
    // we don't match XMLStrings. Defaulting to the super
    // causes us to create a string, but at this point
    // this only seems to get called in key processing.
    // Maybe we can live with it?
    
/*
    int h = m_hash;

    if (h == 0)
    {
      int off = m_start;
      int len = m_length;
      FastStringBuffer fsb = fsb();

      for (int i = 0; i < len; i++)
      {
        h = 31 * h + fsb.charAt(off);

        off++;
      }

      m_hash = h;
    }
    */

    return super.hashCode(); // h;
  }

  /**
   * Tests if this string starts with the specified prefix beginning
   * a specified index.
   *
   * @param   prefix    the prefix.
   * @param   toffset   where to begin looking in the string.
   * @return  <code>true</code> if the character sequence represented by the
   *          argument is a prefix of the substring of this object starting
   *          at index <code>toffset</code>; <code>false</code> otherwise.
   *          The result is <code>false</code> if <code>toffset</code> is
   *          negative or greater than the length of this
   *          <code>String</code> object; otherwise the result is the same
   *          as the result of the expression
   *          <pre>
   *          this.subString(toffset).startsWith(prefix)
   *          </pre>
   * @exception java.lang.NullPointerException if <code>prefix</code> is
   *          <code>null</code>.
   */
  public boolean startsWith(XMLString prefix, int toffset)
  {

    FastStringBuffer fsb = fsb();
    int to = m_start + toffset;
    int tlim = m_start + m_length;
    int po = 0;
    int pc = prefix.length();

    // Note: toffset might be near -1>>>1.
    if ((toffset < 0) || (toffset > m_length - pc))
    {
      return false;
    }

    while (--pc >= 0)
    {
      if (fsb.charAt(to) != prefix.charAt(po))
      {
        return false;
      }

      to++;
      po++;
    }

    return true;
  }

  /**
   * Tests if this string starts with the specified prefix.
   *
   * @param   prefix   the prefix.
   * @return  <code>true</code> if the character sequence represented by the
   *          argument is a prefix of the character sequence represented by
   *          this string; <code>false</code> otherwise.
   *          Note also that <code>true</code> will be returned if the
   *          argument is an empty string or is equal to this
   *          <code>String</code> object as determined by the
   *          {@link #equals(Object)} method.
   * @exception java.lang.NullPointerException if <code>prefix</code> is
   *          <code>null</code>.
   * @since   JDK1. 0
   */
  public boolean startsWith(XMLString prefix)
  {
    return startsWith(prefix, 0);
  }

  /**
   * Returns the index within this string of the first occurrence of the
   * specified character. If a character with value <code>ch</code> occurs
   * in the character sequence represented by this <code>String</code>
   * object, then the index of the first such occurrence is returned --
   * that is, the smallest value <i>k</i> such that:
   * <blockquote><pre>
   * this.charAt(<i>k</i>) == ch
   * </pre></blockquote>
   * is <code>true</code>. If no such character occurs in this string,
   * then <code>-1</code> is returned.
   *
   * @param   ch   a character.
   * @return  the index of the first occurrence of the character in the
   *          character sequence represented by this object, or
   *          <code>-1</code> if the character does not occur.
   */
  public int indexOf(int ch)
  {
    return indexOf(ch, 0);
  }