string.java

linux下建立JAVA虚拟机的源码KAFFE

	if (!ignoreCase) {
		while (len-- > 0) {
			if (this.value[thisPos] != that.value[thatPos]) {
				return false;
			}
			thisPos++;
			thatPos++;
		}
	} else {
		while (len-- > 0) {
			if (Character.toLowerCase(this.value[thisPos])
			    != Character.toLowerCase(that.value[thatPos])
			  && Character.toUpperCase(this.value[thisPos])
			    != Character.toUpperCase(that.value[thatPos])) {
				return false;
			}
			thisPos++;
			thatPos++;
		}
	}
	return true;
}

public boolean regionMatches( int toffset, String other, int ooffset, int len) {
	return regionMatches( false, toffset, other, ooffset, len);
}

public String replace(char oldChar, char newChar) {
	if (oldChar == newChar) {
		return (this);
	}

	char buf[] = new char[count];
	boolean replaced = false;

	for (int pos = 0; pos < count; pos++) {
		char cc = value[offset+pos];
		if ( cc == oldChar) {
			replaced = true;
			buf[pos] = newChar;
		}
		else {
			buf[pos] = cc;
		}
	}

	if (!replaced) {
		return (this);
	}
	else {
		return (new String( 0, count, buf));
	}
}

public boolean startsWith( String prefix) {
	return regionMatches( false, 0, prefix, 0, prefix.count);
}

public boolean startsWith( String prefix, int toffset) {
	return regionMatches( false, toffset, prefix, 0, prefix.count);
}

public String substring( int sIdx) {
	return substring( sIdx, count);
}

/*
 * shared data
 */
public String substring( int sIdx, int eIdx) {
	if ( sIdx < 0)     throw new StringIndexOutOfBoundsException( sIdx);
	if ( eIdx > count) throw new StringIndexOutOfBoundsException( eIdx);
	if ( sIdx > eIdx)  throw new StringIndexOutOfBoundsException( eIdx-sIdx);

	if ( ( sIdx == 0) && ( eIdx  == count ) )
		return this;

	return new String( offset+sIdx, offset+eIdx, value);

}

public CharSequence subSequence( int sIdx, int eIdx) {
        return substring( sIdx, eIdx);
}

public char[] toCharArray() {
	char buf[] = new char[count];
	if ( count > 0)
		getChars( 0, count, buf, 0);

	return buf;
}

public String toLowerCase() {
	return toLowerCase( Locale.getDefault());
}

public String toLowerCase( Locale lcl) {
	char buf[] = new char[count];
	for (int pos = 0; pos < count; pos++)
		buf[pos] = Character.toLowerCase( value[offset+pos]);

	return new String( 0, count, buf);
}

public String toString() {
	return this;
}

public String toUpperCase() {
	return toUpperCase( Locale.getDefault());
}

public String toUpperCase( Locale lcl) {
	char buf[] = new char[count];
	for (int pos=0; pos < count; pos++)
		buf[pos] = Character.toUpperCase( value[offset+pos]);

	return new String( 0, count, buf);
}

public String trim() {
	int i0 = offset;
	int i1 = offset+count-1;

	for ( ;(i0 <= i1) && (value[i0] <= ' '); i0++ );
	if ( i0 > i1 ) return "";
	for ( ;(i1 > i0) && (value[i1] <= ' '); i1-- );

	return substring( i0-offset, i1+1-offset);
}

    /* valueOf methods taken from GNU Classpath */
  /**
   * Returns a String representation of an Object. This is "null" if the
   * object is null, otherwise it is <code>obj.toString()</code> (which
   * can be null).
   *
   * @param obj the Object
   * @return the string conversion of obj
   */
  public static String valueOf(Object obj)
  {
    return obj == null ? "null" : obj.toString();
  }

  /**
   * Returns a String representation of a character array. Subsequent
   * changes to the array do not affect the String.
   *
   * @param data the character array
   * @return a String containing the same character sequence as data
   * @throws NullPointerException if data is null
   * @see #valueOf(char[], int, int)
   * @see #String(char[])
   */
  public static String valueOf(char[] data)
  {
    return valueOf (data, 0, data.length);
  }

  /**
   * Returns a String representing the character sequence of the char array,
   * starting at the specified offset, and copying chars up to the specified
   * count. Subsequent changes to the array do not affect the String.
   *
   * @param data character array
   * @param offset position (base 0) to start copying out of data
   * @param count the number of characters from data to copy
   * @return String containing the chars from data[offset..offset+count]
   * @throws NullPointerException if data is null
   * @throws IndexOutOfBoundsException if (offset &lt; 0 || count &lt; 0
   *         || offset + count &gt; data.length)
   *         (while unspecified, this is a StringIndexOutOfBoundsException)
   * @see #String(char[], int, int)
   */
  public static String valueOf(char[] data, int offset, int count)
  {
    return new String(data, offset, count, false);
  }

  /**
   * Returns a String representing a boolean.
   *
   * @param b the boolean
   * @return "true" if b is true, else "false"
   */
  public static String valueOf(boolean b)
  {
    return b ? "true" : "false";
  }

  /**
   * Returns a String representing a character.
   *
   * @param c the character
   * @return String containing the single character c
   */
  public static String valueOf(char c)
  {
    // Package constructor avoids an array copy.
    return new String(new char[] { c }, 0, 1, true);
  }

  /**
   * Returns a String representing an integer.
   *
   * @param i the integer
   * @return String containing the integer in base 10
   * @see Integer#toString(int)
   */
  public static String valueOf(int i)
  {
    // See Integer to understand why we call the two-arg variant.
    return Integer.toString(i, 10);
  }

  /**
   * Returns a String representing a long.
   *
   * @param l the long
   * @return String containing the long in base 10
   * @see Long#toString(long)
   */
  public static String valueOf(long l)
  {
    return Long.toString(l);
  }

  /**
   * Returns a String representing a float.
   *
   * @param f the float
   * @return String containing the float
   * @see Float#toString(float)
   */
  public static String valueOf(float f)
  {
    return Float.toString(f);
  }

  /**
   * Returns a String representing a double.
   *
   * @param d the double
   * @return String containing the double
   * @see Double#toString(double)
   */
  public static String valueOf(double d)
  {
    return Double.toString(d);
  }

public String intern() {
	return interned ? this : intern0(this);
}

private native static synchronized String intern0(String str);

/* Custom only ....
protected void finalize() throws Throwable {
	if (interned == true) {
		unintern0(this);
	}
	super.finalize();
}

final native public static synchronized void unintern0(String str);
*/

  /**
   * Creates a new String using the character sequence represented by
   * the StringBuilder. Subsequent changes to buf do not affect the String.
   *
   * @param buffer StringBuilder to copy
   * @throws NullPointerException if buffer is null
   */
  public String(StringBuilder buffer)
  {
    this(buffer.value, 0, buffer.count);
  }

  /**
   * Special constructor which can share an array when safe to do so.
   *
   * @param data the characters to copy
   * @param offset the location to start from
   * @param count the number of characters to use
   * @param dont_copy true if the array is trusted, and need not be copied
   * @throws NullPointerException if chars is null
   * @throws StringIndexOutOfBoundsException if bounds check fails
   */
  String(char[] data, int offset, int count, boolean dont_copy)
  {
    if (offset < 0 || count < 0 || offset + count > data.length)
      throw new StringIndexOutOfBoundsException();
    if (dont_copy)
      {
        value = data;
        this.offset = offset;
      }
    else
      {
        value = new char[count];
        System.arraycopy(data, offset, value, 0, count);
        this.offset = 0;
      }
    this.count = count;
  }


  /**
   * Returns the value array of the given string if it is zero based or a
   * copy of it that is zero based (stripping offset and making length equal
   * to count). Used for accessing the char[]s of gnu.java.lang.CharData.
   * Package private for use in Character.
   */
  static char[] zeroBasedStringValue(String s)
  {
    char[] value;

    if (s.offset == 0 && s.count == s.value.length)
      value = s.value;
    else
      {
        int count = s.count;
        value = new char[count];
        System.arraycopy(s.value, s.offset, value, 0, count);
      }

    return value;
  }

  /**
   * Test if this String matches a regular expression. This is shorthand for
   * <code>{@link Pattern}.matches(regex, this)</code>.
   *
   * @param regex the pattern to match
   * @return true if the pattern matches
   * @throws NullPointerException if regex is null
   * @throws PatternSyntaxException if regex is invalid
   * @see Pattern#matches(String, CharSequence)
   * @since 1.4
   */
  public boolean matches(String regex)
  {
    return Pattern.matches(regex, this);
  }

  /**
   * Replaces the first substring match of the regular expression with a
   * given replacement. This is shorthand for <code>{@link Pattern}
   *   .compile(regex).matcher(this).replaceFirst(replacement)</code>.
   *
   * @param regex the pattern to match
   * @param replacement the replacement string
   * @return the modified string
   * @throws NullPointerException if regex or replacement is null
   * @throws PatternSyntaxException if regex is invalid
   * @see #replaceAll(String, String)
   * @see Pattern#compile(String)
   * @see Pattern#matcher(CharSequence)
   * @see Matcher#replaceFirst(String)
   * @since 1.4
   */
  public String replaceFirst(String regex, String replacement)
  {
    return Pattern.compile(regex).matcher(this).replaceFirst(replacement);
  }

  /**
   * Replaces all matching substrings of the regular expression with a
   * given replacement. This is shorthand for <code>{@link Pattern}
   *   .compile(regex).matcher(this).replaceAll(replacement)</code>.
   *
   * @param regex the pattern to match
   * @param replacement the replacement string
   * @return the modified string
   * @throws NullPointerException if regex or replacement is null
   * @throws PatternSyntaxException if regex is invalid
   * @see #replaceFirst(String, String)
   * @see Pattern#compile(String)
   * @see Pattern#matcher(CharSequence)
   * @see Matcher#replaceAll(String)
   * @since 1.4
   */
  public String replaceAll(String regex, String replacement)
  {
    return Pattern.compile(regex).matcher(this).replaceAll(replacement);
  }

  /**
   * Split this string around the matches of a regular expression. Each
   * element of the returned array is the largest block of characters not
   * terminated by the regular expression, in the order the matches are found.
   *
   * <p>The limit affects the length of the array. If it is positive, the
   * array will contain at most n elements (n - 1 pattern matches). If
   * negative, the array length is unlimited, but there can be trailing empty
   * entries. if 0, the array length is unlimited, and trailing empty entries
   * are discarded.
   *
   * <p>For example, splitting "boo:and:foo" yields:<br>
   * <table border=0>
   * <th><td>Regex</td> <td>Limit</td> <td>Result</td></th>
   * <tr><td>":"</td>   <td>2</td>  <td>{ "boo", "and:foo" }</td></tr>
   * <tr><td>":"</td>   <td>t</td>  <td>{ "boo", "and", "foo" }</td></tr>
   * <tr><td>":"</td>   <td>-2</td> <td>{ "boo", "and", "foo" }</td></tr>
   * <tr><td>"o"</td>   <td>5</td>  <td>{ "b", "", ":and:f", "", "" }</td></tr>
   * <tr><td>"o"</td>   <td>-2</td> <td>{ "b", "", ":and:f", "", "" }</td></tr>
   * <tr><td>"o"</td>   <td>0</td>  <td>{ "b", "", ":and:f" }</td></tr>
   * </table>
   *
   * <p>This is shorthand for
   * <code>{@link Pattern}.compile(regex).split(this, limit)</code>.
   *
   * @param regex the pattern to match
   * @param limit the limit threshold
   * @return the array of split strings
   * @throws NullPointerException if regex or replacement is null
   * @throws PatternSyntaxException if regex is invalid
   * @see Pattern#compile(String)
   * @see Pattern#split(CharSequence, int)
   * @since 1.4
   */
  public String[] split(String regex, int limit)
  {
    return Pattern.compile(regex).split(this, limit);
  }

  /**
   * Split this string around the matches of a regular expression. Each
   * element of the returned array is the largest block of characters not
   * terminated by the regular expression, in the order the matches are found.
   * The array length is unlimited, and trailing empty entries are discarded,
   * as though calling <code>split(regex, 0)</code>.
   *
   * @param regex the pattern to match
   * @return the array of split strings
   * @throws NullPointerException if regex or replacement is null
   * @throws PatternSyntaxException if regex is invalid
   * @see #split(String, int)
   * @see Pattern#compile(String)
   * @see Pattern#split(CharSequence, int)
   * @since 1.4
   */
  public String[] split(String regex)
  {
    return Pattern.compile(regex).split(this, 0);
  }


  /**
   * Returns true iff this String contains the sequence of Characters
   * described in s.
   * @param s the CharSequence
   * @return true iff this String contains s
   */
  public boolean contains (CharSequence s)
  {
    return this.indexOf(s.toString()) != -1;
  }

  /**
   * Returns a string that is this string with all instances of the sequence
   * represented by <code>target</code> replaced by the sequence in 
   * <code>replacement</code>.
   * @param target the sequence to be replaced
   * @param replacement the sequence used as the replacement
   * @return the string constructed as above
   */
  public String replace (CharSequence target, CharSequence replacement)
  {
    String targetString = target.toString();
    String replaceString = replacement.toString();
    int targetLength = target.length();
    int replaceLength = replacement.length();
    
    int startPos = this.indexOf(targetString);
    StringBuilder result = new StringBuilder(this);    
    while (startPos != -1)
      {
        // Replace the target with the replacement
        result.replace(startPos, startPos + targetLength, replaceString);

        // Search for a new occurrence of the target
        startPos = result.indexOf(targetString, startPos + replaceLength);
      }
    return result.toString();
  }
  
  /**
   * Return the index into this String that is offset from the given index by 
   * <code>codePointOffset</code> code points.
   * @param index the index at which to start
   * @param codePointOffset the number of code points to offset
   * @return the index into this String that is <code>codePointOffset</code>
   * code points offset from <code>index</code>.
   * 
   * @throws IndexOutOfBoundsException if index is negative or larger than the
   * length of this string.
   * @throws IndexOutOfBoundsException if codePointOffset is positive and the
   * substring starting with index has fewer than codePointOffset code points.
   * @throws IndexOutOfBoundsException if codePointOffset is negative and the
   * substring ending with index has fewer than (-codePointOffset) code points.
   * @since 1.5
   */
  public int offsetByCodePoints(int index, int codePointOffset)
  {
    if (index < 0 || index > count)
      throw new IndexOutOfBoundsException();
    
    return Character.offsetByCodePoints(value, offset, count, offset + index,
                                        codePointOffset);
  }
}