xstring.java

java1.6众多例子参考

   * <i>k</i> such that:
   * <blockquote><pre>
   * this.startsWith(str, <i>k</i>)
   * </pre></blockquote>
   * is <code>true</code>.
   *
   * @param   str   any string.
   * @return  if the string argument occurs as a substring within this
   *          object, then the index of the first character of the first
   *          such substring is returned; if it does not occur as a
   *          substring, <code>-1</code> is returned.
   * @exception java.lang.NullPointerException if <code>str</code> is
   *          <code>null</code>.
   */
  public int indexOf(XMLString str)
  {
    return str().indexOf(str.toString());
  }

  /**
   * Returns the index within this string of the first occurrence of the
   * specified substring, starting at the specified index. The integer
   * returned is the smallest value <i>k</i> such that:
   * <blockquote><pre>
   * this.startsWith(str, <i>k</i>) && (<i>k</i> >= fromIndex)
   * </pre></blockquote>
   * is <code>true</code>.
   * <p>
   * There is no restriction on the value of <code>fromIndex</code>. If
   * it is negative, it has the same effect as if it were zero: this entire
   * string may be searched. If it is greater than the length of this
   * string, it has the same effect as if it were equal to the length of
   * this string: <code>-1</code> is returned.
   *
   * @param   str         the substring to search for.
   * @param   fromIndex   the index to start the search from.
   * @return  If the string argument occurs as a substring within this
   *          object at a starting index no smaller than
   *          <code>fromIndex</code>, then the index of the first character
   *          of the first such substring is returned. If it does not occur
   *          as a substring starting at <code>fromIndex</code> or beyond,
   *          <code>-1</code> is returned.
   * @exception java.lang.NullPointerException if <code>str</code> is
   *          <code>null</code>
   */
  public int indexOf(String str, int fromIndex)
  {
    return str().indexOf(str, fromIndex);
  }

  /**
   * Returns the index within this string of the rightmost occurrence
   * of the specified substring.  The rightmost empty string "" is
   * considered to occur at the index value <code>this.length()</code>.
   * The returned index is the largest value <i>k</i> such that
   * <blockquote><pre>
   * this.startsWith(str, k)
   * </pre></blockquote>
   * is true.
   *
   * @param   str   the substring to search for.
   * @return  if the string argument occurs one or more times as a substring
   *          within this object, then the index of the first character of
   *          the last such substring is returned. If it does not occur as
   *          a substring, <code>-1</code> is returned.
   * @exception java.lang.NullPointerException  if <code>str</code> is
   *          <code>null</code>.
   */
  public int lastIndexOf(String str)
  {
    return str().lastIndexOf(str);
  }

  /**
   * Returns the index within this string of the last occurrence of
   * the specified substring.
   *
   * @param   str         the substring to search for.
   * @param   fromIndex   the index to start the search from. There is no
   *          restriction on the value of fromIndex. If it is greater than
   *          the length of this string, it has the same effect as if it
   *          were equal to the length of this string: this entire string
   *          may be searched. If it is negative, it has the same effect
   *          as if it were -1: -1 is returned.
   * @return  If the string argument occurs one or more times as a substring
   *          within this object at a starting index no greater than
   *          <code>fromIndex</code>, then the index of the first character of
   *          the last such substring is returned. If it does not occur as a
   *          substring starting at <code>fromIndex</code> or earlier,
   *          <code>-1</code> is returned.
   * @exception java.lang.NullPointerException if <code>str</code> is
   *          <code>null</code>.
   */
  public int lastIndexOf(String str, int fromIndex)
  {
    return str().lastIndexOf(str, fromIndex);
  }

  /**
   * Returns a new string that is a substring of this string. The
   * substring begins with the character at the specified index and
   * extends to the end of this string. <p>
   * Examples:
   * <blockquote><pre>
   * "unhappy".substring(2) returns "happy"
   * "Harbison".substring(3) returns "bison"
   * "emptiness".substring(9) returns "" (an empty string)
   * </pre></blockquote>
   *
   * @param      beginIndex   the beginning index, inclusive.
   * @return     the specified substring.
   * @exception  IndexOutOfBoundsException  if
   *             <code>beginIndex</code> is negative or larger than the
   *             length of this <code>String</code> object.
   */
  public XMLString substring(int beginIndex)
  {
    return new XString(str().substring(beginIndex));
  }

  /**
   * Returns a new string that is a substring of this string. The
   * substring begins at the specified <code>beginIndex</code> and
   * extends to the character at index <code>endIndex - 1</code>.
   * Thus the length of the substring is <code>endIndex-beginIndex</code>.
   *
   * @param      beginIndex   the beginning index, inclusive.
   * @param      endIndex     the ending index, exclusive.
   * @return     the specified substring.
   * @exception  IndexOutOfBoundsException  if the
   *             <code>beginIndex</code> is negative, or
   *             <code>endIndex</code> is larger than the length of
   *             this <code>String</code> object, or
   *             <code>beginIndex</code> is larger than
   *             <code>endIndex</code>.
   */
  public XMLString substring(int beginIndex, int endIndex)
  {
    return new XString(str().substring(beginIndex, endIndex));
  }

  /**
   * Concatenates the specified string to the end of this string.
   *
   * @param   str   the <code>String</code> that is concatenated to the end
   *                of this <code>String</code>.
   * @return  a string that represents the concatenation of this object's
   *          characters followed by the string argument's characters.
   * @exception java.lang.NullPointerException if <code>str</code> is
   *          <code>null</code>.
   */
  public XMLString concat(String str)
  {

    // %REVIEW% Make an FSB here?
    return new XString(str().concat(str));
  }

  /**
   * Converts all of the characters in this <code>String</code> to lower
   * case using the rules of the given <code>Locale</code>.
   *
   * @param locale use the case transformation rules for this locale
   * @return the String, converted to lowercase.
   * @see     java.lang.Character#toLowerCase(char)
   * @see     java.lang.String#toUpperCase(Locale)
   */
  public XMLString toLowerCase(Locale locale)
  {
    return new XString(str().toLowerCase(locale));
  }

  /**
   * Converts all of the characters in this <code>String</code> to lower
   * case using the rules of the default locale, which is returned
   * by <code>Locale.getDefault</code>.
   * <p>
   *
   * @return  the string, converted to lowercase.
   * @see     java.lang.Character#toLowerCase(char)
   * @see     java.lang.String#toLowerCase(Locale)
   */
  public XMLString toLowerCase()
  {
    return new XString(str().toLowerCase());
  }

  /**
   * Converts all of the characters in this <code>String</code> to upper
   * case using the rules of the given locale.
   * @param locale use the case transformation rules for this locale
   * @return the String, converted to uppercase.
   * @see     java.lang.Character#toUpperCase(char)
   * @see     java.lang.String#toLowerCase(Locale)
   */
  public XMLString toUpperCase(Locale locale)
  {
    return new XString(str().toUpperCase(locale));
  }

  /**
   * Converts all of the characters in this <code>String</code> to upper
   * case using the rules of the default locale, which is returned
   * by <code>Locale.getDefault</code>.
   *
   * <p>
   * If no character in this string has a different uppercase version,
   * based on calling the <code>toUpperCase</code> method defined by
   * <code>Character</code>, then the original string is returned.
   * <p>
   * Otherwise, this method creates a new <code>String</code> object
   * representing a character sequence identical in length to the
   * character sequence represented by this <code>String</code> object and
   * with every character equal to the result of applying the method
   * <code>Character.toUpperCase</code> to the corresponding character of
   * this <code>String</code> object. <p>
   * Examples:
   * <blockquote><pre>
   * "Fahrvergn&uuml;gen".toUpperCase() returns "FAHRVERGN&Uuml;GEN"
   * "Visit Ljubinje!".toUpperCase() returns "VISIT LJUBINJE!"
   * </pre></blockquote>
   *
   * @return  the string, converted to uppercase.
   * @see     java.lang.Character#toUpperCase(char)
   * @see     java.lang.String#toUpperCase(Locale)
   */
  public XMLString toUpperCase()
  {
    return new XString(str().toUpperCase());
  }

  /**
   * Removes white space from both ends of this string.
   *
   * @return  this string, with white space removed from the front and end.
   */
  public XMLString trim()
  {
    return new XString(str().trim());
  }

  /**
   * Returns whether the specified <var>ch</var> conforms to the XML 1.0 definition
   * of whitespace.  Refer to <A href="http://www.w3.org/TR/1998/REC-xml-19980210#NT-S">
   * the definition of <CODE>S</CODE></A> for details.
   * @param   ch      Character to check as XML whitespace.
   * @return          =true if <var>ch</var> is XML whitespace; otherwise =false.
   */
  private static boolean isSpace(char ch)
  {
    return XMLCharacterRecognizer.isWhiteSpace(ch);  // Take the easy way out for now.
  }

  /**
   * Conditionally trim all leading and trailing whitespace in the specified String.
   * All strings of white space are
   * replaced by a single space character (#x20), except spaces after punctuation which
   * receive double spaces if doublePunctuationSpaces is true.
   * This function may be useful to a formatter, but to get first class
   * results, the formatter should probably do it's own white space handling
   * based on the semantics of the formatting object.
   *
   * @param   trimHead    Trim leading whitespace?
   * @param   trimTail    Trim trailing whitespace?
   * @param   doublePunctuationSpaces    Use double spaces for punctuation?
   * @return              The trimmed string.
   */
  public XMLString fixWhiteSpace(boolean trimHead, boolean trimTail,
                                 boolean doublePunctuationSpaces)
  {

    // %OPT% !!!!!!!
    int len = this.length();
    char[] buf = new char[len];

    this.getChars(0, len, buf, 0);

    boolean edit = false;
    int s;

    for (s = 0; s < len; s++)
    {
      if (isSpace(buf[s]))
      {
        break;
      }
    }

    /* replace S to ' '. and ' '+ -> single ' '. */
    int d = s;
    boolean pres = false;

    for (; s < len; s++)
    {
      char c = buf[s];

      if (isSpace(c))
      {
        if (!pres)
        {
          if (' ' != c)
          {
            edit = true;
          }

          buf[d++] = ' ';

          if (doublePunctuationSpaces && (s != 0))
          {
            char prevChar = buf[s - 1];

            if (!((prevChar == '.') || (prevChar == '!')
                  || (prevChar == '?')))
            {
              pres = true;
            }
          }
          else
          {
            pres = true;
          }
        }
        else
        {
          edit = true;
          pres = true;
        }
      }
      else
      {
        buf[d++] = c;
        pres = false;
      }
    }

    if (trimTail && 1 <= d && ' ' == buf[d - 1])
    {
      edit = true;

      d--;
    }

    int start = 0;

    if (trimHead && 0 < d && ' ' == buf[0])
    {
      edit = true;

      start++;
    }

    XMLStringFactory xsf = XMLStringFactoryImpl.getFactory();

    return edit ? xsf.newstr(new String(buf, start, d - start)) : this;
  }
  
  /**
   * @see com.sun.org.apache.xpath.internal.XPathVisitable#callVisitors(ExpressionOwner, XPathVisitor)
   */
  public void callVisitors(ExpressionOwner owner, XPathVisitor visitor)
  {
  	visitor.visitStringLiteral(owner, this);
  }

}