/*
* @(#)StringBuilder.java 1.11 05/11/17
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
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(), 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
* @version 1.11, 11/17/05
* @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);
}
/**
* @see java.lang.String#valueOf(java.lang.Object)
* @see #append(java.lang.String)
*/
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;
}
/**
* @throws IndexOutOfBoundsException {@inheritDoc}
*/
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;
}
public StringBuilder append(char str[], int offset, int len) {
super.append(str, offset, len);
return this;
}
/**
* @see java.lang.String#valueOf(boolean)
* @see #append(java.lang.String)
*/
public StringBuilder append(boolean b) {
super.append(b);
return this;
}
public StringBuilder append(char c) {
super.append(c);
return this;
}
/**
* @see java.lang.String#valueOf(int)
* @see #append(java.lang.String)
*/
public StringBuilder append(int i) {
super.append(i);
return this;
}
/**
* @see java.lang.String#valueOf(long)
* @see #append(java.lang.String)
*/
public StringBuilder append(long lng) {
super.append(lng);
return this;
}
/**
* @see java.lang.String#valueOf(float)
* @see #append(java.lang.String)
*/
public StringBuilder append(float f) {
super.append(f);
return this;
}
/**
* @see java.lang.String#valueOf(double)
* @see #append(java.lang.String)
*/
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}
* @see java.lang.String#valueOf(java.lang.Object)
* @see #insert(int, java.lang.String)
* @see #length()
*/
public StringBuilder insert(int offset, Object obj) {
return insert(offset, String.valueOf(obj));
}
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
* @see #length()
*/
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}
* @see java.lang.String#valueOf(boolean)
* @see #insert(int, java.lang.String)
* @see #length()
*/
public StringBuilder insert(int offset, boolean b) {
super.insert(offset, b);
return this;
}
/**
* @throws IndexOutOfBoundsException {@inheritDoc}
* @see #length()
*/
public StringBuilder insert(int offset, char c) {
super.insert(offset, c);
return this;
}
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
* @see java.lang.String#valueOf(int)
* @see #insert(int, java.lang.String)
* @see #length()
*/
public StringBuilder insert(int offset, int i) {
return insert(offset, String.valueOf(i));
}
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
* @see java.lang.String#valueOf(long)
* @see #insert(int, java.lang.String)
* @see #length()
*/
public StringBuilder insert(int offset, long l) {
return insert(offset, String.valueOf(l));
}
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
* @see java.lang.String#valueOf(float)
* @see #insert(int, java.lang.String)
* @see #length()
*/
public StringBuilder insert(int offset, float f) {
return insert(offset, String.valueOf(f));
}
/**
* @throws StringIndexOutOfBoundsException {@inheritDoc}
* @see java.lang.String#valueOf(double)
* @see #insert(int, java.lang.String)
* @see #length()
*/
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 String.indexOf(value, 0, count,
str.toCharArray(), 0, str.length(), 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();
}
}
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