/*

  * Copyright (c) 2003, 2008, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the LICENSE file that accompanied this code.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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  * questions.

  */

 package java.lang;

 /**

  * A mutable sequence of characters.  This class provides an API compatible

  * with <code>StringBuffer</code>, but with no guarantee of synchronization.

  * This class is designed for use as a drop-in replacement for

  * <code>StringBuffer</code> in places where the string buffer was being

  * used by a single thread (as is generally the case).   Where possible,

  * it is recommended that this class be used in preference to

  * <code>StringBuffer</code> as it will be faster under most implementations.

  *

  * <p>The principal operations on a <code>StringBuilder</code> are the

  * <code>append</code> and <code>insert</code> methods, which are

  * overloaded so as to accept data of any type. Each effectively

  * converts a given datum to a string and then appends or inserts the

  * characters of that string to the string builder. The

  * <code>append</code> method always adds these characters at the end

  * of the builder; the <code>insert</code> method adds the characters at

  * a specified point.

  * <p>

  * For example, if <code>z</code> refers to a string builder object

  * whose current contents are "<code>start</code>", then

  * the method call <code>z.append("le")</code> would cause the string

  * builder to contain "<code>startle</code>", whereas

  * <code>z.insert(4, "le")</code> would alter the string builder to

  * contain "<code>starlet</code>".

  * <p>

  * In general, if sb refers to an instance of a <code>StringBuilder</code>,

  * then <code>sb.append(x)</code> has the same effect as

  * <code>sb.insert(sb.length(),&nbsp;x)</code>.

  *

  * Every string builder has a capacity. As long as the length of the

  * character sequence contained in the string builder does not exceed

  * the capacity, it is not necessary to allocate a new internal

  * buffer. If the internal buffer overflows, it is automatically made larger.

  *

  * <p>Instances of <code>StringBuilder</code> are not safe for

  * use by multiple threads. If such synchronization is required then it is

  * recommended that {@link java.lang.StringBuffer} be used.

  *

  * @author      Michael McCloskey

  * @see         java.lang.StringBuffer

  * @see         java.lang.String

  * @since       1.5

  */

 public final class StringBuilder

     extends AbstractStringBuilder

     implements java.io.Serializable, CharSequence

 {

     /** use serialVersionUID for interoperability */

     static final long serialVersionUID = 4383685877147921099L;

     /**

      * Constructs a string builder with no characters in it and an

      * initial capacity of 16 characters.

      */

     public StringBuilder() {

         super(16);

     }

     /**

      * Constructs a string builder with no characters in it and an

      * initial capacity specified by the <code>capacity</code> argument.

      *

      * @param      capacity  the initial capacity.

      * @throws     NegativeArraySizeException  if the <code>capacity</code>

      *               argument is less than <code>0</code>.

      */

     public StringBuilder(int capacity) {

         super(capacity);

     }

     /**

      * Constructs a string builder initialized to the contents of the

      * specified string. The initial capacity of the string builder is

      * <code>16</code> plus the length of the string argument.

      *

      * @param   str   the initial contents of the buffer.

      * @throws    NullPointerException if <code>str</code> is <code>null</code>

      */

     public StringBuilder(String str) {

         super(str.length() + 16);

         append(str);

     }

     /**

      * Constructs a string builder that contains the same characters

      * as the specified <code>CharSequence</code>. The initial capacity of

      * the string builder is <code>16</code> plus the length of the

      * <code>CharSequence</code> argument.

      *

      * @param      seq   the sequence to copy.

      * @throws    NullPointerException if <code>seq</code> is <code>null</code>

      */

     public StringBuilder(CharSequence seq) {

         this(seq.length() + 16);

         append(seq);

     }

     public StringBuilder append(Object obj) {

         return append(String.valueOf(obj));

     }

     public StringBuilder append(String str) {

         super.append(str);

         return this;

     }

     // Appends the specified string builder to this sequence.

     private StringBuilder append(StringBuilder sb) {

         if (sb == null)

             return append("null");

         int len = sb.length();

         int newcount = count + len;

         if (newcount > value.length)

             expandCapacity(newcount);

         sb.getChars(0, len, value, count);

         count = newcount;

         return this;

     }

     /**

      * Appends the specified <tt>StringBuffer</tt> to this sequence.

      * <p>

      * The characters of the <tt>StringBuffer</tt> argument are appended,

      * in order, to this sequence, increasing the

      * length of this sequence by the length of the argument.

      * If <tt>sb</tt> is <tt>null</tt>, then the four characters

      * <tt>"null"</tt> are appended to this sequence.

      * <p>

      * Let <i>n</i> be the length of this character sequence just prior to

      * execution of the <tt>append</tt> method. Then the character at index

      * <i>k</i> in the new character sequence is equal to the character at

      * index <i>k</i> in the old character sequence, if <i>k</i> is less than

      * <i>n</i>; otherwise, it is equal to the character at index <i>k-n</i>

      * in the argument <code>sb</code>.

      *

      * @param   sb   the <tt>StringBuffer</tt> to append.

      * @return  a reference to this object.

      */

     public StringBuilder append(StringBuffer sb) {

         super.append(sb);

         return this;

     }

     /**

      */

     public StringBuilder append(CharSequence s) {

         if (s == null)

             s = "null";

         if (s instanceof String)

             return this.append((String)s);

         if (s instanceof StringBuffer)

             return this.append((StringBuffer)s);

         if (s instanceof StringBuilder)

             return this.append((StringBuilder)s);

         return this.append(s, 0, s.length());

     }

     /**

      * @throws     IndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder append(CharSequence s, int start, int end) {

         super.append(s, start, end);

         return this;

     }

     public StringBuilder append(char[] str) {

         super.append(str);

         return this;

     }

     /**

      * @throws IndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder append(char[] str, int offset, int len) {

         super.append(str, offset, len);

         return this;

     }

     public StringBuilder append(boolean b) {

         super.append(b);

         return this;

     }

     public StringBuilder append(char c) {

         super.append(c);

         return this;

     }

     public StringBuilder append(int i) {

         super.append(i);

         return this;

     }

     public StringBuilder append(long lng) {

         super.append(lng);

         return this;

     }

     public StringBuilder append(float f) {

         super.append(f);

         return this;

     }

     public StringBuilder append(double d) {

         super.append(d);

         return this;

     }

     /**

      * @since 1.5

      */

     public StringBuilder appendCodePoint(int codePoint) {

         super.appendCodePoint(codePoint);

         return this;

     }

     /**

      * @throws StringIndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder delete(int start, int end) {

         super.delete(start, end);

         return this;

     }

     /**

      * @throws StringIndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder deleteCharAt(int index) {

         super.deleteCharAt(index);

         return this;

     }

     /**

      * @throws StringIndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder replace(int start, int end, String str) {

         super.replace(start, end, str);

         return this;

     }

     /**

      * @throws StringIndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder insert(int index, char[] str, int offset,

                                 int len)

     {

         super.insert(index, str, offset, len);

         return this;

     }

     /**

      * @throws StringIndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder insert(int offset, Object obj) {

         return insert(offset, String.valueOf(obj));

     }

     /**

      * @throws StringIndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder insert(int offset, String str) {

         super.insert(offset, str);

         return this;

     }

     /**

      * @throws StringIndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder insert(int offset, char[] str) {

         super.insert(offset, str);

         return this;

     }

     /**

      * @throws IndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder insert(int dstOffset, CharSequence s) {

         if (s == null)

             s = "null";

         if (s instanceof String)

             return this.insert(dstOffset, (String)s);

         return this.insert(dstOffset, s, 0, s.length());

     }

     /**

      * @throws IndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder insert(int dstOffset, CharSequence s,

                                 int start, int end)

     {

         super.insert(dstOffset, s, start, end);

         return this;

     }

     /**

      * @throws StringIndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder insert(int offset, boolean b) {

         super.insert(offset, b);

         return this;

     }

     /**

      * @throws IndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder insert(int offset, char c) {

         super.insert(offset, c);

         return this;

     }

     /**

      * @throws StringIndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder insert(int offset, int i) {

         return insert(offset, String.valueOf(i));

     }

     /**

      * @throws StringIndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder insert(int offset, long l) {

         return insert(offset, String.valueOf(l));

     }

     /**

      * @throws StringIndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder insert(int offset, float f) {

         return insert(offset, String.valueOf(f));

     }

     /**

      * @throws StringIndexOutOfBoundsException {@inheritDoc}

      */

     public StringBuilder insert(int offset, double d) {

         return insert(offset, String.valueOf(d));

     }

     /**

      * @throws NullPointerException {@inheritDoc}

      */

     public int indexOf(String str) {

         return indexOf(str, 0);

     }

     /**

      * @throws NullPointerException {@inheritDoc}

      */

     public int indexOf(String str, int fromIndex) {

         return super.indexOf(str, fromIndex);

     }

     /**

      * @throws NullPointerException {@inheritDoc}

      */

     public int lastIndexOf(String str) {

         return lastIndexOf(str, count);

     }

     /**

      * @throws NullPointerException {@inheritDoc}

      */

     public int lastIndexOf(String str, int fromIndex) {

         return String.lastIndexOf(value, 0, count,

                               str.toCharArray(), 0, str.length(), fromIndex);

     }

     public StringBuilder reverse() {

         super.reverse();

         return this;

     }

     public String toString() {

         // Create a copy, don't share the array

         return new String(value, 0, count);

     }

     /**

      * Save the state of the <tt>StringBuilder</tt> instance to a stream

      * (that is, serialize it).

      *

      * @serialData the number of characters currently stored in the string

      *             builder (<tt>int</tt>), followed by the characters in the

      *             string builder (<tt>char[]</tt>).   The length of the

      *             <tt>char</tt> array may be greater than the number of

      *             characters currently stored in the string builder, in which

      *             case extra characters are ignored.

      */

 //    private void writeObject(java.io.ObjectOutputStream s)

 //        throws java.io.IOException {

 //        s.defaultWriteObject();

 //        s.writeInt(count);

 //        s.writeObject(value);

 //    }

     /**

      * readObject is called to restore the state of the StringBuffer from

      * a stream.

      */

 //    private void readObject(java.io.ObjectInputStream s)

 //        throws java.io.IOException, ClassNotFoundException {

 //        s.defaultReadObject();

 //        count = s.readInt();

 //        value = (char[]) s.readObject();

 //    }

 }