1191 lines
39 KiB
Java
1191 lines
39 KiB
Java
/* StringBuffer.java -- Growable strings
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Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005
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Free Software Foundation, Inc.
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This file is part of GNU Classpath.
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GNU Classpath is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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GNU Classpath is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GNU Classpath; see the file COPYING. If not, write to the
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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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02110-1301 USA.
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Linking this library statically or dynamically with other modules is
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making a combined work based on this library. Thus, the terms and
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conditions of the GNU General Public License cover the whole
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combination.
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As a special exception, the copyright holders of this library give you
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permission to link this library with independent modules to produce an
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executable, regardless of the license terms of these independent
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modules, and to copy and distribute the resulting executable under
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terms of your choice, provided that you also meet, for each linked
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independent module, the terms and conditions of the license of that
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module. An independent module is a module which is not derived from
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or based on this library. If you modify this library, you may extend
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this exception to your version of the library, but you are not
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obligated to do so. If you do not wish to do so, delete this
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exception statement from your version. */
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package java.lang;
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import java.io.Serializable;
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/**
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* <code>StringBuffer</code> represents a changeable <code>String</code>.
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* It provides the operations required to modify the
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* <code>StringBuffer</code>, including insert, replace, delete, append,
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* and reverse. It is thread-safe; meaning that all modifications to a buffer
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* are in synchronized methods.
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*
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* <p><code>StringBuffer</code>s are variable-length in nature, so even if
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* you initialize them to a certain size, they can still grow larger than
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* that. <em>Capacity</em> indicates the number of characters the
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* <code>StringBuffer</code> can have in it before it has to grow (growing
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* the char array is an expensive operation involving <code>new</code>).
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*
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* <p>Incidentally, compilers often implement the String operator "+"
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* by using a <code>StringBuffer</code> operation:<br>
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* <code>a + b</code><br>
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* is the same as<br>
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* <code>new StringBuffer().append(a).append(b).toString()</code>.
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*
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* <p>Classpath's StringBuffer is capable of sharing memory with Strings for
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* efficiency. This will help when a StringBuffer is converted to a String
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* and the StringBuffer is not changed after that (quite common when performing
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* string concatenation).
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*
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* @author Paul Fisher
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* @author John Keiser
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* @author Tom Tromey
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* @author Eric Blake (ebb9@email.byu.edu)
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* @see String
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* @since 1.0
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* @status updated to 1.4
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*/
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public final class StringBuffer
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implements Serializable, CharSequence, Appendable
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{
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// Implementation note: if you change this class, you usually will
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// want to change StringBuilder as well.
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/**
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* Compatible with JDK 1.0+.
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*/
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private static final long serialVersionUID = 3388685877147921107L;
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/**
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* Index of next available character (and thus the size of the current
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* string contents). Note that this has permissions set this way so that
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* String can get the value.
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*
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* @serial the number of characters in the buffer
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*/
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int count;
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/**
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* The buffer. Note that this has permissions set this way so that String
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* can get the value.
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*
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* @serial the buffer
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*/
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char[] value;
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/**
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* True if the buffer is shared with another object (StringBuffer or
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* String); this means the buffer must be copied before writing to it again.
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* Note that this has permissions set this way so that String can get the
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* value.
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*
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* @serial whether the buffer is shared
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*/
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boolean shared;
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/**
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* The default capacity of a buffer.
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*/
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private static final int DEFAULT_CAPACITY = 16;
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/**
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* Create a new StringBuffer with default capacity 16.
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*/
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public StringBuffer()
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{
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this(DEFAULT_CAPACITY);
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}
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/**
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* Create an empty <code>StringBuffer</code> with the specified initial
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* capacity.
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*
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* @param capacity the initial capacity
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* @throws NegativeArraySizeException if capacity is negative
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*/
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public StringBuffer(int capacity)
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{
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value = new char[capacity];
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}
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/**
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* Create a new <code>StringBuffer</code> with the characters in the
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* specified <code>String</code>. Initial capacity will be the size of the
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* String plus 16.
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*
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* @param str the <code>String</code> to convert
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* @throws NullPointerException if str is null
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*/
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public StringBuffer(String str)
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{
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// Unfortunately, because the size is 16 larger, we cannot share.
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count = str.count;
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value = new char[count + DEFAULT_CAPACITY];
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str.getChars(0, count, value, 0);
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}
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/**
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* Create a new <code>StringBuffer</code> with the characters in the
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* specified <code>CharSequence</code>. Initial capacity will be the
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* length of the sequence plus 16; if the sequence reports a length
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* less than or equal to 0, then the initial capacity will be 16.
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*
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* @param seq the initializing <code>CharSequence</code>
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* @throws NullPointerException if str is null
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* @since 1.5
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*/
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public StringBuffer(CharSequence seq)
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{
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int len = seq.length();
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count = len <= 0 ? 0 : len;
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value = new char[count + DEFAULT_CAPACITY];
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for (int i = 0; i < len; ++i)
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value[i] = seq.charAt(i);
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}
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/**
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* Get the length of the <code>String</code> this <code>StringBuffer</code>
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* would create. Not to be confused with the <em>capacity</em> of the
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* <code>StringBuffer</code>.
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*
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* @return the length of this <code>StringBuffer</code>
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* @see #capacity()
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* @see #setLength(int)
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*/
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public synchronized int length()
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{
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return count;
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}
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/**
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* Get the total number of characters this <code>StringBuffer</code> can
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* support before it must be grown. Not to be confused with <em>length</em>.
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*
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* @return the capacity of this <code>StringBuffer</code>
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* @see #length()
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* @see #ensureCapacity(int)
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*/
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public synchronized int capacity()
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{
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return value.length;
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}
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/**
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* Increase the capacity of this <code>StringBuffer</code>. This will
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* ensure that an expensive growing operation will not occur until
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* <code>minimumCapacity</code> is reached. The buffer is grown to the
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* larger of <code>minimumCapacity</code> and
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* <code>capacity() * 2 + 2</code>, if it is not already large enough.
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*
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* @param minimumCapacity the new capacity
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* @see #capacity()
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*/
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public synchronized void ensureCapacity(int minimumCapacity)
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{
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ensureCapacity_unsynchronized(minimumCapacity);
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}
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/**
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* Set the length of this StringBuffer. If the new length is greater than
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* the current length, all the new characters are set to '\0'. If the new
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* length is less than the current length, the first <code>newLength</code>
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* characters of the old array will be preserved, and the remaining
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* characters are truncated.
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*
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* @param newLength the new length
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* @throws IndexOutOfBoundsException if the new length is negative
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* (while unspecified, this is a StringIndexOutOfBoundsException)
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* @see #length()
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*/
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public synchronized void setLength(int newLength)
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{
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if (newLength < 0)
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throw new StringIndexOutOfBoundsException(newLength);
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int valueLength = value.length;
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/* Always call ensureCapacity_unsynchronized in order to preserve
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copy-on-write semantics. */
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ensureCapacity_unsynchronized(newLength);
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if (newLength < valueLength)
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{
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/* If the StringBuffer's value just grew, then we know that
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value is newly allocated and the region between count and
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newLength is filled with '\0'. */
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count = newLength;
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}
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else
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{
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/* The StringBuffer's value doesn't need to grow. However,
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we should clear out any cruft that may exist. */
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while (count < newLength)
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value[count++] = '\0';
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}
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}
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/**
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* Get the character at the specified index.
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*
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* @param index the index of the character to get, starting at 0
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* @return the character at the specified index
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* @throws IndexOutOfBoundsException if index is negative or >= length()
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*/
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public synchronized char charAt(int index)
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{
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if (index < 0 || index >= count)
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throw new StringIndexOutOfBoundsException(index);
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return value[index];
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}
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/**
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* Get the code point at the specified index. This is like #charAt(int),
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* but if the character is the start of a surrogate pair, and the
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* following character completes the pair, then the corresponding
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* supplementary code point is returned.
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* @param index the index of the codepoint to get, starting at 0
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* @return the codepoint at the specified index
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* @throws IndexOutOfBoundsException if index is negative or >= length()
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* @since 1.5
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*/
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public synchronized int codePointAt(int index)
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{
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return Character.codePointAt(value, index, count);
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}
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/**
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* Get the code point before the specified index. This is like
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* #codePointAt(int), but checks the characters at <code>index-1</code> and
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* <code>index-2</code> to see if they form a supplementary code point.
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* @param index the index just past the codepoint to get, starting at 0
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* @return the codepoint at the specified index
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* @throws IndexOutOfBoundsException if index is negative or >= length()
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* @since 1.5
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*/
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public synchronized int codePointBefore(int index)
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{
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// Character.codePointBefore() doesn't perform this check. We
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// could use the CharSequence overload, but this is just as easy.
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if (index >= count)
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throw new IndexOutOfBoundsException();
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return Character.codePointBefore(value, index, 1);
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}
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/**
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* Get the specified array of characters. <code>srcOffset - srcEnd</code>
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* characters will be copied into the array you pass in.
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*
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* @param srcOffset the index to start copying from (inclusive)
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* @param srcEnd the index to stop copying from (exclusive)
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* @param dst the array to copy into
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* @param dstOffset the index to start copying into
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* @throws NullPointerException if dst is null
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* @throws IndexOutOfBoundsException if any source or target indices are
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* out of range (while unspecified, source problems cause a
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* StringIndexOutOfBoundsException, and dest problems cause an
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* ArrayIndexOutOfBoundsException)
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* @see System#arraycopy(Object, int, Object, int, int)
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*/
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public synchronized void getChars(int srcOffset, int srcEnd,
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char[] dst, int dstOffset)
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{
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if (srcOffset < 0 || srcEnd > count || srcEnd < srcOffset)
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throw new StringIndexOutOfBoundsException();
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VMSystem.arraycopy(value, srcOffset, dst, dstOffset, srcEnd - srcOffset);
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}
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/**
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* Set the character at the specified index.
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*
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* @param index the index of the character to set starting at 0
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* @param ch the value to set that character to
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* @throws IndexOutOfBoundsException if index is negative or >= length()
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* (while unspecified, this is a StringIndexOutOfBoundsException)
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*/
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public synchronized void setCharAt(int index, char ch)
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{
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if (index < 0 || index >= count)
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throw new StringIndexOutOfBoundsException(index);
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// Call ensureCapacity to enforce copy-on-write.
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ensureCapacity_unsynchronized(count);
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value[index] = ch;
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}
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/**
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* Append the <code>String</code> value of the argument to this
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* <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
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* to <code>String</code>.
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*
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* @param obj the <code>Object</code> to convert and append
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* @return this <code>StringBuffer</code>
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* @see String#valueOf(Object)
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* @see #append(String)
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*/
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public StringBuffer append(Object obj)
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{
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return append(obj == null ? "null" : obj.toString());
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}
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/**
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* Append the <code>String</code> to this <code>StringBuffer</code>. If
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* str is null, the String "null" is appended.
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*
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* @param str the <code>String</code> to append
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* @return this <code>StringBuffer</code>
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*/
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public synchronized StringBuffer append(String str)
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{
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if (str == null)
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str = "null";
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int len = str.count;
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ensureCapacity_unsynchronized(count + len);
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str.getChars(0, len, value, count);
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count += len;
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return this;
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}
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/**
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* Append the <code>StringBuffer</code> value of the argument to this
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* <code>StringBuffer</code>. This behaves the same as
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* <code>append((Object) stringBuffer)</code>, except it is more efficient.
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*
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* @param stringBuffer the <code>StringBuffer</code> to convert and append
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* @return this <code>StringBuffer</code>
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* @see #append(Object)
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* @since 1.4
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*/
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public synchronized StringBuffer append(StringBuffer stringBuffer)
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{
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if (stringBuffer == null)
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return append("null");
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synchronized (stringBuffer)
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{
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int len = stringBuffer.count;
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ensureCapacity_unsynchronized(count + len);
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VMSystem.arraycopy(stringBuffer.value, 0, value, count, len);
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count += len;
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}
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return this;
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}
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/**
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* Append the <code>char</code> array to this <code>StringBuffer</code>.
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* This is similar (but more efficient) than
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* <code>append(new String(data))</code>, except in the case of null.
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*
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* @param data the <code>char[]</code> to append
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* @return this <code>StringBuffer</code>
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* @throws NullPointerException if <code>str</code> is <code>null</code>
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* @see #append(char[], int, int)
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*/
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public StringBuffer append(char[] data)
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{
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return append(data, 0, data.length);
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}
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/**
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* Append part of the <code>char</code> array to this
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* <code>StringBuffer</code>. This is similar (but more efficient) than
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* <code>append(new String(data, offset, count))</code>, except in the case
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* of null.
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*
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* @param data the <code>char[]</code> to append
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* @param offset the start location in <code>str</code>
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* @param count the number of characters to get from <code>str</code>
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* @return this <code>StringBuffer</code>
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* @throws NullPointerException if <code>str</code> is <code>null</code>
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* @throws IndexOutOfBoundsException if offset or count is out of range
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* (while unspecified, this is a StringIndexOutOfBoundsException)
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*/
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public synchronized StringBuffer append(char[] data, int offset, int count)
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{
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if (offset < 0 || count < 0 || offset > data.length - count)
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throw new StringIndexOutOfBoundsException();
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ensureCapacity_unsynchronized(this.count + count);
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VMSystem.arraycopy(data, offset, value, this.count, count);
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this.count += count;
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return this;
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}
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/**
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* Append the code point to this <code>StringBuffer</code>.
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* This is like #append(char), but will append two characters
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* if a supplementary code point is given.
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*
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* @param code the code point to append
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* @return this <code>StringBuffer</code>
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* @see Character#toChars(int, char[], int)
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* @since 1.5
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*/
|
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public synchronized StringBuffer appendCodePoint(int code)
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{
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int len = Character.charCount(code);
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ensureCapacity_unsynchronized(count + len);
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Character.toChars(code, value, count);
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count += len;
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return this;
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}
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|
|
/**
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* Append the <code>String</code> value of the argument to this
|
|
* <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
|
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* to <code>String</code>.
|
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*
|
|
* @param bool the <code>boolean</code> to convert and append
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* @return this <code>StringBuffer</code>
|
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* @see String#valueOf(boolean)
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*/
|
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public StringBuffer append(boolean bool)
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{
|
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return append(bool ? "true" : "false");
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}
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|
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/**
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* Append the <code>char</code> to this <code>StringBuffer</code>.
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*
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* @param ch the <code>char</code> to append
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|
* @return this <code>StringBuffer</code>
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*/
|
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public synchronized StringBuffer append(char ch)
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|
{
|
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ensureCapacity_unsynchronized(count + 1);
|
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value[count++] = ch;
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return this;
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}
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|
|
/**
|
|
* Append the characters in the <code>CharSequence</code> to this
|
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* buffer.
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*
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* @param seq the <code>CharSequence</code> providing the characters
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* @return this <code>StringBuffer</code>
|
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* @since 1.5
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*/
|
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public synchronized StringBuffer append(CharSequence seq)
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{
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return append(seq, 0, seq.length());
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}
|
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|
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/**
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|
* Append some characters from the <code>CharSequence</code> to this
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* buffer. If the argument is null, the four characters "null" are
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* appended.
|
|
*
|
|
* @param seq the <code>CharSequence</code> providing the characters
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|
* @param start the starting index
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* @param end one past the final index
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* @return this <code>StringBuffer</code>
|
|
* @since 1.5
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*/
|
|
public synchronized StringBuffer append(CharSequence seq, int start, int end)
|
|
{
|
|
if (seq == null)
|
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return append("null");
|
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if (end - start > 0)
|
|
{
|
|
ensureCapacity_unsynchronized(count + end - start);
|
|
for (; start < end; ++start)
|
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value[count++] = seq.charAt(start);
|
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}
|
|
return this;
|
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}
|
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|
|
/**
|
|
* 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
|
|
* @param sequence the <code>CharSequence</code> to insert
|
|
* @param start the starting index of the subsequence
|
|
* @param end one past the ending index of the subsequence
|
|
* @return this <code>StringBuffer</code>
|
|
* @throws IndexOutOfBoundsException if offset, start,
|
|
* or end are out of bounds
|
|
* @since 1.5
|
|
*/
|
|
public synchronized StringBuffer insert(int offset, CharSequence sequence,
|
|
int start, int end)
|
|
{
|
|
if (sequence == null)
|
|
sequence = "null";
|
|
if (start < 0 || end < 0 || start > end || end > sequence.length())
|
|
throw new IndexOutOfBoundsException();
|
|
int len = end - start;
|
|
ensureCapacity_unsynchronized(count + len);
|
|
VMSystem.arraycopy(value, offset, value, offset + len, count - offset);
|
|
for (int i = start; i < end; ++i)
|
|
value[offset++] = sequence.charAt(i);
|
|
count += len;
|
|
return this;
|
|
}
|
|
|
|
/**
|
|
* Insert the <code>char[]</code> argument into this
|
|
* <code>StringBuffer</code>.
|
|
*
|
|
* @param offset the place to insert in this buffer
|
|
* @param data the <code>char[]</code> to insert
|
|
* @return this <code>StringBuffer</code>
|
|
* @throws NullPointerException if <code>data</code> is <code>null</code>
|
|
* @throws StringIndexOutOfBoundsException if offset is out of bounds
|
|
* @see #insert(int, char[], int, int)
|
|
*/
|
|
public StringBuffer insert(int offset, char[] data)
|
|
{
|
|
return insert(offset, data, 0, data.length);
|
|
}
|
|
|
|
/**
|
|
* 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 bool the <code>boolean</code> to convert and insert
|
|
* @return this <code>StringBuffer</code>
|
|
* @throws StringIndexOutOfBoundsException if offset is out of bounds
|
|
* @see String#valueOf(boolean)
|
|
*/
|
|
public StringBuffer insert(int offset, boolean bool)
|
|
{
|
|
return insert(offset, bool ? "true" : "false");
|
|
}
|
|
|
|
/**
|
|
* Insert the <code>char</code> argument into this <code>StringBuffer</code>.
|
|
*
|
|
* @param offset the place to insert in this buffer
|
|
* @param ch the <code>char</code> to insert
|
|
* @return this <code>StringBuffer</code>
|
|
* @throws StringIndexOutOfBoundsException if offset is out of bounds
|
|
*/
|
|
public synchronized StringBuffer insert(int offset, char ch)
|
|
{
|
|
if (offset < 0 || offset > count)
|
|
throw new StringIndexOutOfBoundsException(offset);
|
|
ensureCapacity_unsynchronized(count + 1);
|
|
VMSystem.arraycopy(value, offset, value, offset + 1, count - offset);
|
|
value[offset] = ch;
|
|
count++;
|
|
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 inum the <code>int</code> to convert and insert
|
|
* @return this <code>StringBuffer</code>
|
|
* @throws StringIndexOutOfBoundsException if offset is out of bounds
|
|
* @see String#valueOf(int)
|
|
*/
|
|
public StringBuffer insert(int offset, int inum)
|
|
{
|
|
return insert(offset, String.valueOf(inum));
|
|
}
|
|
|
|
/**
|
|
* 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 lnum the <code>long</code> to convert and insert
|
|
* @return this <code>StringBuffer</code>
|
|
* @throws StringIndexOutOfBoundsException if offset is out of bounds
|
|
* @see String#valueOf(long)
|
|
*/
|
|
public StringBuffer insert(int offset, long lnum)
|
|
{
|
|
return insert(offset, Long.toString(lnum, 10));
|
|
}
|
|
|
|
/**
|
|
* 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 fnum the <code>float</code> to convert and insert
|
|
* @return this <code>StringBuffer</code>
|
|
* @throws StringIndexOutOfBoundsException if offset is out of bounds
|
|
* @see String#valueOf(float)
|
|
*/
|
|
public StringBuffer insert(int offset, float fnum)
|
|
{
|
|
return insert(offset, Float.toString(fnum));
|
|
}
|
|
|
|
/**
|
|
* 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 dnum the <code>double</code> to convert and insert
|
|
* @return this <code>StringBuffer</code>
|
|
* @throws StringIndexOutOfBoundsException if offset is out of bounds
|
|
* @see String#valueOf(double)
|
|
*/
|
|
public StringBuffer insert(int offset, double dnum)
|
|
{
|
|
return insert(offset, Double.toString(dnum));
|
|
}
|
|
|
|
/**
|
|
* Finds the first instance of a substring in this StringBuffer.
|
|
*
|
|
* @param str String to find
|
|
* @return location (base 0) of the String, or -1 if not found
|
|
* @throws NullPointerException if str is null
|
|
* @see #indexOf(String, int)
|
|
* @since 1.4
|
|
*/
|
|
public int indexOf(String str)
|
|
{
|
|
return indexOf(str, 0);
|
|
}
|
|
|
|
/**
|
|
* Finds the first instance of a String in this StringBuffer, starting at
|
|
* a given index. If starting index is less than 0, the search starts at
|
|
* the beginning of this String. If the starting index is greater than the
|
|
* length of this String, or the substring is not found, -1 is returned.
|
|
*
|
|
* @param str String to find
|
|
* @param fromIndex index to start the search
|
|
* @return location (base 0) of the String, or -1 if not found
|
|
* @throws NullPointerException if str is null
|
|
* @since 1.4
|
|
*/
|
|
public synchronized int indexOf(String str, int fromIndex)
|
|
{
|
|
if (fromIndex < 0)
|
|
fromIndex = 0;
|
|
int limit = count - str.count;
|
|
for ( ; fromIndex <= limit; fromIndex++)
|
|
if (regionMatches(fromIndex, str))
|
|
return fromIndex;
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* Finds the last instance of a substring in this StringBuffer.
|
|
*
|
|
* @param str String to find
|
|
* @return location (base 0) of the String, or -1 if not found
|
|
* @throws NullPointerException if str is null
|
|
* @see #lastIndexOf(String, int)
|
|
* @since 1.4
|
|
*/
|
|
public int lastIndexOf(String str)
|
|
{
|
|
return lastIndexOf(str, count - str.count);
|
|
}
|
|
|
|
/**
|
|
* Finds the last instance of a String in this StringBuffer, starting at a
|
|
* given index. If starting index is greater than the maximum valid index,
|
|
* then the search begins at the end of this String. If the starting index
|
|
* is less than zero, or the substring is not found, -1 is returned.
|
|
*
|
|
* @param str String to find
|
|
* @param fromIndex index to start the search
|
|
* @return location (base 0) of the String, or -1 if not found
|
|
* @throws NullPointerException if str is null
|
|
* @since 1.4
|
|
*/
|
|
public synchronized int lastIndexOf(String str, int fromIndex)
|
|
{
|
|
fromIndex = Math.min(fromIndex, count - str.count);
|
|
for ( ; fromIndex >= 0; fromIndex--)
|
|
if (regionMatches(fromIndex, str))
|
|
return fromIndex;
|
|
return -1;
|
|
}
|
|
|
|
/**
|
|
* Reverse the characters in this StringBuffer. The same sequence of
|
|
* characters exists, but in the reverse index ordering.
|
|
*
|
|
* @return this <code>StringBuffer</code>
|
|
*/
|
|
public synchronized StringBuffer reverse()
|
|
{
|
|
// Call ensureCapacity to enforce copy-on-write.
|
|
ensureCapacity_unsynchronized(count);
|
|
for (int i = count >> 1, j = count - i; --i >= 0; ++j)
|
|
{
|
|
char c = value[i];
|
|
value[i] = value[j];
|
|
value[j] = c;
|
|
}
|
|
return this;
|
|
}
|
|
|
|
/**
|
|
* Convert this <code>StringBuffer</code> to a <code>String</code>. The
|
|
* String is composed of the characters currently in this StringBuffer. Note
|
|
* that the result is a copy, and that future modifications to this buffer
|
|
* do not affect the String.
|
|
*
|
|
* @return the characters in this StringBuffer
|
|
*/
|
|
public String toString()
|
|
{
|
|
// The string will set this.shared = true.
|
|
return new String(this);
|
|
}
|
|
|
|
/**
|
|
* This may reduce the amount of memory used by the StringBuffer,
|
|
* by resizing the internal array to remove unused space. However,
|
|
* this method is not required to resize, so this behavior cannot
|
|
* be relied upon.
|
|
* @since 1.5
|
|
*/
|
|
public synchronized void trimToSize()
|
|
{
|
|
int wouldSave = value.length - count;
|
|
// Some random heuristics: if we save less than 20 characters, who
|
|
// cares.
|
|
if (wouldSave < 20)
|
|
return;
|
|
// If we save more than 200 characters, shrink.
|
|
// If we save more than 1/4 of the buffer, shrink.
|
|
if (wouldSave > 200 || wouldSave * 4 > value.length)
|
|
{
|
|
char[] newValue = new char[count];
|
|
VMSystem.arraycopy(value, 0, newValue, 0, count);
|
|
value = newValue;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Return the number of code points between two indices in the
|
|
* <code>StringBuffer</code>. An unpaired surrogate counts as a
|
|
* code point for this purpose. Characters outside the indicated
|
|
* range are not examined, even if the range ends in the middle of a
|
|
* surrogate pair.
|
|
*
|
|
* @param start the starting index
|
|
* @param end one past the ending index
|
|
* @return the number of code points
|
|
* @since 1.5
|
|
*/
|
|
public synchronized int codePointCount(int start, int end)
|
|
{
|
|
if (start < 0 || end >= count || start > end)
|
|
throw new StringIndexOutOfBoundsException();
|
|
|
|
int count = 0;
|
|
while (start < end)
|
|
{
|
|
char base = value[start];
|
|
if (base < Character.MIN_HIGH_SURROGATE
|
|
|| base > Character.MAX_HIGH_SURROGATE
|
|
|| start == end
|
|
|| start == count
|
|
|| value[start + 1] < Character.MIN_LOW_SURROGATE
|
|
|| value[start + 1] > Character.MAX_LOW_SURROGATE)
|
|
{
|
|
// Nothing.
|
|
}
|
|
else
|
|
{
|
|
// Surrogate pair.
|
|
++start;
|
|
}
|
|
++start;
|
|
++count;
|
|
}
|
|
return count;
|
|
}
|
|
|
|
/**
|
|
* Starting at the given index, this counts forward by the indicated
|
|
* number of code points, and then returns the resulting index. An
|
|
* unpaired surrogate counts as a single code point for this
|
|
* purpose.
|
|
*
|
|
* @param start the starting index
|
|
* @param codePoints the number of code points
|
|
* @return the resulting index
|
|
* @since 1.5
|
|
*/
|
|
public synchronized int offsetByCodePoints(int start, int codePoints)
|
|
{
|
|
while (codePoints > 0)
|
|
{
|
|
char base = value[start];
|
|
if (base < Character.MIN_HIGH_SURROGATE
|
|
|| base > Character.MAX_HIGH_SURROGATE
|
|
|| start == count
|
|
|| value[start + 1] < Character.MIN_LOW_SURROGATE
|
|
|| value[start + 1] > Character.MAX_LOW_SURROGATE)
|
|
{
|
|
// Nothing.
|
|
}
|
|
else
|
|
{
|
|
// Surrogate pair.
|
|
++start;
|
|
}
|
|
++start;
|
|
--codePoints;
|
|
}
|
|
return start;
|
|
}
|
|
|
|
/**
|
|
* An unsynchronized version of ensureCapacity, used internally to avoid
|
|
* the cost of a second lock on the same object. This also has the side
|
|
* effect of duplicating the array, if it was shared (to form copy-on-write
|
|
* semantics).
|
|
*
|
|
* @param minimumCapacity the minimum capacity
|
|
* @see #ensureCapacity(int)
|
|
*/
|
|
private void ensureCapacity_unsynchronized(int minimumCapacity)
|
|
{
|
|
if (shared || minimumCapacity > value.length)
|
|
{
|
|
// We don't want to make a larger vector when `shared' is
|
|
// set. If we do, then setLength becomes very inefficient
|
|
// when repeatedly reusing a StringBuffer in a loop.
|
|
int max = (minimumCapacity > value.length
|
|
? value.length * 2 + 2
|
|
: value.length);
|
|
minimumCapacity = (minimumCapacity < max ? max : minimumCapacity);
|
|
char[] nb = new char[minimumCapacity];
|
|
VMSystem.arraycopy(value, 0, nb, 0, count);
|
|
value = nb;
|
|
shared = false;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Predicate which determines if a substring of this matches another String
|
|
* starting at a specified offset for each String and continuing for a
|
|
* specified length. This is more efficient than creating a String to call
|
|
* indexOf on.
|
|
*
|
|
* @param toffset index to start comparison at for this String
|
|
* @param other non-null String to compare to region of this
|
|
* @return true if regions match, false otherwise
|
|
* @see #indexOf(String, int)
|
|
* @see #lastIndexOf(String, int)
|
|
* @see String#regionMatches(boolean, int, String, int, int)
|
|
*/
|
|
private boolean regionMatches(int toffset, String other)
|
|
{
|
|
int len = other.count;
|
|
int index = other.offset;
|
|
while (--len >= 0)
|
|
if (value[toffset++] != other.value[index++])
|
|
return false;
|
|
return true;
|
|
}
|
|
}
|