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	/*
	* Copyright (c) 2003, 2013, 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
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package java.lang;


	/**
	* A mutable sequence of characters. This class provides an API compatible
	* with {@code StringBuffer}, but with no guarantee of synchronization.
	* This class is designed for use as a drop-in replacement for
	* {@code StringBuffer} 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} as it will be faster under most implementations.
	*
	* <p>The principal operations on a {@code StringBuilder} are the
	* {@code append} and {@code insert} 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} method always adds these characters at the end
	* of the builder; the {@code insert} method adds the characters at
	* a specified point.
	* <p>
	* For example, if {@code z} refers to a string builder object
	* whose current contents are "{@code start}", then
	* the method call {@code z.append("le")} would cause the string
	* builder to contain "{@code startle}", whereas
	* {@code z.insert(4, "le")} would alter the string builder to
	* contain "{@code starlet}".
	* <p>
	* In general, if sb refers to an instance of a {@code StringBuilder},
	* then {@code sb.append(x)} has the same effect as
	* {@code sb.insert(sb.length(), x)}.
	* <p>
	* 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} are not safe for
	* use by multiple threads. If such synchronization is required then it is
	* recommended that {@link java.lang.StringBuffer} be used.
	*
	* <p>Unless otherwise noted, passing a {@code null} argument to a constructor
	* or method in this class will cause a {@link NullPointerException} to be
	* thrown.
	*
	* @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} argument.
	*
	* @param capacity the initial capacity.
	* @throws NegativeArraySizeException if the {@code capacity}
	* argument is less than {@code 0}.
	*/
	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} plus the length of the string argument.
	*
	* @param str the initial contents of the buffer.
	*/
	public StringBuilder(String str) {
	super(str.length() + 16);
	append(str);
	}

	/**
	* Constructs a string builder that contains the same characters
	* as the specified {@code CharSequence}. The initial capacity of
	* the string builder is {@code 16} plus the length of the
	* {@code CharSequence} argument.
	*
	* @param seq the sequence to copy.
	*/
	public StringBuilder(CharSequence seq) {
	this(seq.length() + 16);
	append(seq);
	}

	@Override
	public StringBuilder append(Object obj) {
	return append(String.valueOf(obj));
	}

	@Override
	public StringBuilder append(String str) {
	super.append(str);
	return this;
	}

	/**
	* Appends the specified {@code StringBuffer} to this sequence.
	* <p>
	* The characters of the {@code StringBuffer} argument are appended,
	* in order, to this sequence, increasing the
	* length of this sequence by the length of the argument.
	* If {@code sb} is {@code null}, then the four characters
	* {@code "null"} are appended to this sequence.
	* <p>
	* Let <i>n</i> be the length of this character sequence just prior to
	* execution of the {@code append} 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}.
	*
	* @param sb the {@code StringBuffer} to append.
	* @return a reference to this object.
	*/
	public StringBuilder append(StringBuffer sb) {
	super.append(sb);
	return this;
	}

	@Override
	public StringBuilder append(CharSequence s) {
	super.append(s);
	return this;
	}

	/**
	* @throws IndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder append(CharSequence s, int start, int end) {
	super.append(s, start, end);
	return this;
	}

	@Override
	public StringBuilder append(char[] str) {
	super.append(str);
	return this;
	}

	/**
	* @throws IndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder append(char[] str, int offset, int len) {
	super.append(str, offset, len);
	return this;
	}

	@Override
	public StringBuilder append(boolean b) {
	super.append(b);
	return this;
	}

	@Override
	public StringBuilder append(char c) {
	super.append(c);
	return this;
	}

	@Override
	public StringBuilder append(int i) {
	super.append(i);
	return this;
	}

	@Override
	public StringBuilder append(long lng) {
	super.append(lng);
	return this;
	}

	@Override
	public StringBuilder append(float f) {
	super.append(f);
	return this;
	}

	@Override
	public StringBuilder append(double d) {
	super.append(d);
	return this;
	}

	/**
	* @since 1.5
	*/
	@Override
	public StringBuilder appendCodePoint(int codePoint) {
	super.appendCodePoint(codePoint);
	return this;
	}

	/**
	* @throws StringIndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder delete(int start, int end) {
	super.delete(start, end);
	return this;
	}

	/**
	* @throws StringIndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder deleteCharAt(int index) {
	super.deleteCharAt(index);
	return this;
	}

	/**
	* @throws StringIndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder replace(int start, int end, String str) {
	super.replace(start, end, str);
	return this;
	}

	/**
	* @throws StringIndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder insert(int index, char[] str, int offset,
	int len)
	{
	super.insert(index, str, offset, len);
	return this;
	}

	/**
	* @throws StringIndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder insert(int offset, Object obj) {
	super.insert(offset, obj);
	return this;
	}

	/**
	* @throws StringIndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder insert(int offset, String str) {
	super.insert(offset, str);
	return this;
	}

	/**
	* @throws StringIndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder insert(int offset, char[] str) {
	super.insert(offset, str);
	return this;
	}

	/**
	* @throws IndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder insert(int dstOffset, CharSequence s) {
	super.insert(dstOffset, s);
	return this;
	}

	/**
	* @throws IndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder insert(int dstOffset, CharSequence s,
	int start, int end)
	{
	super.insert(dstOffset, s, start, end);
	return this;
	}

	/**
	* @throws StringIndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder insert(int offset, boolean b) {
	super.insert(offset, b);
	return this;
	}

	/**
	* @throws IndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder insert(int offset, char c) {
	super.insert(offset, c);
	return this;
	}

	/**
	* @throws StringIndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder insert(int offset, int i) {
	super.insert(offset, i);
	return this;
	}

	/**
	* @throws StringIndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder insert(int offset, long l) {
	super.insert(offset, l);
	return this;
	}

	/**
	* @throws StringIndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder insert(int offset, float f) {
	super.insert(offset, f);
	return this;
	}

	/**
	* @throws StringIndexOutOfBoundsException {@inheritDoc}
	*/
	@Override
	public StringBuilder insert(int offset, double d) {
	super.insert(offset, d);
	return this;
	}

	@Override
	public int indexOf(String str) {
	return super.indexOf(str);
	}

	@Override
	public int indexOf(String str, int fromIndex) {
	return super.indexOf(str, fromIndex);
	}

	@Override
	public int lastIndexOf(String str) {
	return super.lastIndexOf(str);
	}

	@Override
	public int lastIndexOf(String str, int fromIndex) {
	return super.lastIndexOf(str, fromIndex);
	}

	@Override
	public StringBuilder reverse() {
	super.reverse();
	return this;
	}

	@Override
	public String toString() {
	// Create a copy, don't share the array
	return new String(value, 0, count);
	}

	/**
	* Save the state of the {@code StringBuilder} instance to a stream
	* (that is, serialize it).
	*
	* @serialData the number of characters currently stored in the string
	* builder ({@code int}), followed by the characters in the
	* string builder ({@code char[]}). The length of the
	* {@code char} 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();
	}

	}

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