stringbuffer.java

gcc的组建

   * @return this <code>StringBuffer</code>
   * @see #append(Object)
   * @since 1.5
   */
  public synchronized StringBuffer append(CharSequence sequence)
  {
    if (sequence == null)
      sequence = "null";
    return append(sequence, 0, sequence.length());
  }

  /**
   * Append the specified subsequence of the <code>CharSequence</code>
   * argument to this <code>StringBuffer</code>.
   *
   * @param sequence the <code>CharSequence</code> to append
   * @param start the starting index
   * @param end one past the ending index
   * @return this <code>StringBuffer</code>
   * @see #append(Object)
   * @since 1.5
   */
  public synchronized StringBuffer append(CharSequence sequence,
					  int start, int end)
  {
    if (sequence == null)
      sequence = "null";
    if (start < 0 || end < 0 || start > end || end > sequence.length())
      throw new IndexOutOfBoundsException();
    ensureCapacity_unsynchronized(this.count + end - start);
    for (int i = start; i < end; ++i)
      value[count++] = sequence.charAt(i);
    return this;
  }

  /**
   * Append the <code>char</code> array to this <code>StringBuffer</code>.
   * This is similar (but more efficient) than
   * <code>append(new String(data))</code>, except in the case of null.
   *
   * @param data the <code>char[]</code> to append
   * @return this <code>StringBuffer</code>
   * @throws NullPointerException if <code>str</code> is <code>null</code>
   * @see #append(char[], int, int)
   */
  public StringBuffer append(char[] data)
  {
    return append(data, 0, data.length);
  }

  /**
   * Append part of the <code>char</code> array to this
   * <code>StringBuffer</code>. This is similar (but more efficient) than
   * <code>append(new String(data, offset, count))</code>, except in the case
   * of null.
   *
   * @param data the <code>char[]</code> to append
   * @param offset the start location in <code>str</code>
   * @param count the number of characters to get from <code>str</code>
   * @return this <code>StringBuffer</code>
   * @throws NullPointerException if <code>str</code> is <code>null</code>
   * @throws IndexOutOfBoundsException if offset or count is out of range
   *         (while unspecified, this is a StringIndexOutOfBoundsException)
   */
  public synchronized StringBuffer append(char[] data, int offset, int count)
  {
    if (offset < 0 || count < 0 || offset > data.length - count)
      throw new StringIndexOutOfBoundsException();
    ensureCapacity_unsynchronized(this.count + count);
    VMSystem.arraycopy(data, offset, value, this.count, count);
    this.count += count;
    return this;
  }

  /**
   * Append the <code>String</code> value of the argument to this
   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
   * to <code>String</code>.
   *
   * @param bool the <code>boolean</code> to convert and append
   * @return this <code>StringBuffer</code>
   * @see String#valueOf(boolean)
   */
  public StringBuffer append(boolean bool)
  {
    return append(bool ? "true" : "false");
  }

  /**
   * Append the <code>char</code> to this <code>StringBuffer</code>.
   *
   * @param ch the <code>char</code> to append
   * @return this <code>StringBuffer</code>
   */
  public synchronized StringBuffer append(char ch)
  {
    ensureCapacity_unsynchronized(count + 1);
    value[count++] = ch;
    return this;
  }

  /**
   * Append the code point to this <code>StringBuffer</code>.
   * This is like #append(char), but will append two characters
   * if a supplementary code point is given.
   *
   * @param code the code point to append
   * @return this <code>StringBuffer</code>
   * @see Character#toChars(int, char[], int)
   * @since 1.5
   */
  public synchronized StringBuffer appendCodePoint(int code)
  {
    int len = Character.charCount(code);
    ensureCapacity_unsynchronized(count + len);
    Character.toChars(code, value, count);
    count += len;
    return this;
  }

  /**
   * Append the <code>String</code> value of the argument to this
   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
   * to <code>String</code>.
   *
   * @param inum the <code>int</code> to convert and append
   * @return this <code>StringBuffer</code>
   * @see String#valueOf(int)
   */
  // This is native in libgcj, for efficiency.
  public StringBuffer append(int inum)
  {
    return append(String.valueOf(inum));
  }

  /**
   * Append the <code>String</code> value of the argument to this
   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
   * to <code>String</code>.
   *
   * @param lnum the <code>long</code> to convert and append
   * @return this <code>StringBuffer</code>
   * @see String#valueOf(long)
   */
  public StringBuffer append(long lnum)
  {
    return append(Long.toString(lnum, 10));
  }

  /**
   * Append the <code>String</code> value of the argument to this
   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
   * to <code>String</code>.
   *
   * @param fnum the <code>float</code> to convert and append
   * @return this <code>StringBuffer</code>
   * @see String#valueOf(float)
   */
  public StringBuffer append(float fnum)
  {
    return append(Float.toString(fnum));
  }

  /**
   * Append the <code>String</code> value of the argument to this
   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
   * to <code>String</code>.
   *
   * @param dnum the <code>double</code> to convert and append
   * @return this <code>StringBuffer</code>
   * @see String#valueOf(double)
   */
  public StringBuffer append(double dnum)
  {
    return append(Double.toString(dnum));
  }

  /**
   * Delete characters from this <code>StringBuffer</code>.
   * <code>delete(10, 12)</code> will delete 10 and 11, but not 12. It is
   * harmless for end to be larger than length().
   *
   * @param start the first character to delete
   * @param end the index after the last character to delete
   * @return this <code>StringBuffer</code>
   * @throws StringIndexOutOfBoundsException if start or end are out of bounds
   * @since 1.2
   */
  public synchronized StringBuffer delete(int start, int end)
  {
    if (start < 0 || start > count || start > end)
      throw new StringIndexOutOfBoundsException(start);
    if (end > count)
      end = count;
    // This will unshare if required.
    ensureCapacity_unsynchronized(count);
    if (count - end != 0)
      VMSystem.arraycopy(value, end, value, start, count - end);
    count -= end - start;
    return this;
  }

  /**
   * Delete a character from this <code>StringBuffer</code>.
   *
   * @param index the index of the character to delete
   * @return this <code>StringBuffer</code>
   * @throws StringIndexOutOfBoundsException if index is out of bounds
   * @since 1.2
   */
  public StringBuffer deleteCharAt(int index)
  {
    return delete(index, index + 1);
  }

  /**
   * Replace characters between index <code>start</code> (inclusive) and
   * <code>end</code> (exclusive) with <code>str</code>. If <code>end</code>
   * is larger than the size of this StringBuffer, all characters after
   * <code>start</code> are replaced.
   *
   * @param start the beginning index of characters to delete (inclusive)
   * @param end the ending index of characters to delete (exclusive)
   * @param str the new <code>String</code> to insert
   * @return this <code>StringBuffer</code>
   * @throws StringIndexOutOfBoundsException if start or end are out of bounds
   * @throws NullPointerException if str is null
   * @since 1.2
   */
  public synchronized StringBuffer replace(int start, int end, String str)
  {
    if (start < 0 || start > count || start > end)
      throw new StringIndexOutOfBoundsException(start);

    int len = str.count;
    // Calculate the difference in 'count' after the replace.
    int delta = len - (end > count ? count : end) + start;
    ensureCapacity_unsynchronized(count + delta);

    if (delta != 0 && end < count)
      VMSystem.arraycopy(value, end, value, end + delta, count - end);

    str.getChars(0, len, value, start);
    count += delta;
    return this;
  }

  /**
   * Creates a substring of this StringBuffer, starting at a specified index
   * and ending at the end of this StringBuffer.
   *
   * @param beginIndex index to start substring (base 0)
   * @return new String which is a substring of this StringBuffer
   * @throws StringIndexOutOfBoundsException if beginIndex is out of bounds
   * @see #substring(int, int)
   * @since 1.2
   */
  public String substring(int beginIndex)
  {
    return substring(beginIndex, count);
  }

  /**
   * Creates a substring of this StringBuffer, starting at a specified index
   * and ending at one character before a specified index. This is implemented
   * the same as <code>substring(beginIndex, endIndex)</code>, to satisfy
   * the CharSequence interface.
   *
   * @param beginIndex index to start at (inclusive, base 0)
   * @param endIndex index to end at (exclusive)
   * @return new String which is a substring of this StringBuffer
   * @throws IndexOutOfBoundsException if beginIndex or endIndex is out of
   *         bounds
   * @see #substring(int, int)
   * @since 1.4
   */
  public CharSequence subSequence(int beginIndex, int endIndex)
  {
    return substring(beginIndex, endIndex);
  }

  /**
   * Creates a substring of this StringBuffer, starting at a specified index
   * and ending at one character before a specified index.
   *
   * @param beginIndex index to start at (inclusive, base 0)
   * @param endIndex index to end at (exclusive)
   * @return new String which is a substring of this StringBuffer
   * @throws StringIndexOutOfBoundsException if beginIndex or endIndex is out
   *         of bounds
   * @since 1.2
   */
  public synchronized String substring(int beginIndex, int endIndex)
  {
    int len = endIndex - beginIndex;
    if (beginIndex < 0 || endIndex > count || endIndex < beginIndex)
      throw new StringIndexOutOfBoundsException();
    if (len == 0)
      return "";
    // Don't copy unless substring is smaller than 1/4 of the buffer.
    boolean share_buffer = ((len << 2) >= value.length);
    if (share_buffer)
      this.shared = true;
    // Package constructor avoids an array copy.
    return new String(value, beginIndex, len, share_buffer);
  }

  /**
   * Insert a subarray of the <code>char[]</code> argument into this
   * <code>StringBuffer</code>.
   *
   * @param offset the place to insert in this buffer
   * @param str the <code>char[]</code> to insert
   * @param str_offset the index in <code>str</code> to start inserting from
   * @param len the number of characters to insert
   * @return this <code>StringBuffer</code>
   * @throws NullPointerException if <code>str</code> is <code>null</code>
   * @throws StringIndexOutOfBoundsException if any index is out of bounds
   * @since 1.2
   */
  public synchronized StringBuffer insert(int offset,
                                          char[] str, int str_offset, int len)
  {
    if (offset < 0 || offset > count || len < 0
        || str_offset < 0 || str_offset > str.length - len)
      throw new StringIndexOutOfBoundsException();
    ensureCapacity_unsynchronized(count + len);
    VMSystem.arraycopy(value, offset, value, offset + len, count - offset);
    VMSystem.arraycopy(str, str_offset, value, offset, len);
    count += len;
    return this;
  }

  /**
   * Insert the <code>String</code> value of the argument into this
   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
   * to <code>String</code>.
   *
   * @param offset the place to insert in this buffer
   * @param obj the <code>Object</code> to convert and insert
   * @return this <code>StringBuffer</code>
   * @exception StringIndexOutOfBoundsException if offset is out of bounds
   * @see String#valueOf(Object)
   */
  public StringBuffer insert(int offset, Object obj)
  {
    return insert(offset, obj == null ? "null" : obj.toString());
  }

  /**
   * Insert the <code>String</code> argument into this
   * <code>StringBuffer</code>. If str is null, the String "null" is used
   * instead.
   *
   * @param offset the place to insert in this buffer
   * @param str the <code>String</code> to insert
   * @return this <code>StringBuffer</code>
   * @throws StringIndexOutOfBoundsException if offset is out of bounds
   */
  public synchronized StringBuffer insert(int offset, String str)
  {
    if (offset < 0 || offset > count)
      throw new StringIndexOutOfBoundsException(offset);
    if (str == null)
      str = "null";
    int len = str.count;
    ensureCapacity_unsynchronized(count + len);
    VMSystem.arraycopy(value, offset, value, offset + len, count - offset);
    str.getChars(0, len, value, offset);
    count += len;
    return this;
  }

  /**
   * Insert the <code>CharSequence</code> argument into this
   * <code>StringBuffer</code>.  If the sequence is null, the String
   * "null" is used instead.
   *
   * @param offset the place to insert in this buffer
   * @param sequence the <code>CharSequence</code> to insert
   * @return this <code>StringBuffer</code>
   * @throws IndexOutOfBoundsException if offset is out of bounds
   * @since 1.5
   */
  public synchronized StringBuffer insert(int offset, CharSequence sequence)
  {
    if (sequence == null)
      sequence = "null";
    return insert(offset, sequence, 0, sequence.length());
  }

  /**
   * Insert a subsequence of the <code>CharSequence</code> argument into this
   * <code>StringBuffer</code>.  If the sequence is null, the String
   * "null" is used instead.
   *
   * @param offset the place to insert in this buffer