java.lang

Class StringBuilder

java.lang.Object

java.lang.StringBuilder

All Implemented Interfaces:

Appendable, CharSequence

public class StringBuilder
extends Object
implements CharSequence, Appendable

A fast way to create strings using multiple appends. This is implemented using a StringBufferImpl that is chosen with deferred binding. Most methods will give expected performance results. Exceptions are setCharAt(int, char), which is O(n), and length(), which forces a toString() and thus should not be used many times on the same StringBuilder. This class is an exact clone of StringBuffer except for the name. Any change made to one should be mirrored in the other.

Constructor Summary

Constructors

Constructor and Description
StringBuilder()
StringBuilder(CharSequence s)
StringBuilder(int ignoredCapacity) This implementation does not track capacity; using this constructor is functionally equivalent to using the zero-argument constructor.
StringBuilder(String s)

Method Summary

Modifier and Type	Method and Description
StringBuilder	append(boolean x)
StringBuilder	append(char x)
StringBuilder	append(char[] x)
StringBuilder	append(char[] x, int start, int len)
StringBuilder	append(CharSequence x)
StringBuilder	append(CharSequence x, int start, int end)
StringBuilder	append(double x)
StringBuilder	append(float x)
StringBuilder	append(int x)
StringBuilder	append(long x)
StringBuilder	append(Object x)
StringBuilder	append(String x)
StringBuilder	append(StringBuffer x)
StringBuilder	appendCodePoint(int x)
int	capacity() This implementation does not track capacity; always returns Integer.MAX_VALUE.
char	charAt(int index)
StringBuilder	delete(int start, int end)
StringBuilder	deleteCharAt(int start)
void	ensureCapacity(int ignoredCapacity) This implementation does not track capacity; calling this method has no effect.
void	getChars(int srcStart, int srcEnd, char[] dst, int dstStart)
int	indexOf(String x)
int	indexOf(String x, int start)
StringBuilder	insert(int index, boolean x)
StringBuilder	insert(int index, char x)
StringBuilder	insert(int index, char[] x)
StringBuilder	insert(int index, char[] x, int offset, int len)
StringBuilder	insert(int index, CharSequence chars)
StringBuilder	insert(int index, CharSequence chars, int start, int end)
StringBuilder	insert(int index, double x)
StringBuilder	insert(int index, float x)
StringBuilder	insert(int index, int x)
StringBuilder	insert(int index, long x)
StringBuilder	insert(int index, Object x)
StringBuilder	insert(int index, String x)
int	lastIndexOf(String s)
int	lastIndexOf(String s, int start)
int	length()
StringBuilder	replace(int start, int end, String toInsert)
StringBuilder	reverse()
void	setCharAt(int index, char x) Warning! This method is much slower than the JRE implementation.
void	setLength(int newLength)
CharSequence	subSequence(int start, int end)
String	substring(int begin)
String	substring(int begin, int end)
String	toString()
void	trimToSize()

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode

Constructor Detail

StringBuilder

public StringBuilder()

StringBuilder

public StringBuilder(CharSequence s)

StringBuilder

public StringBuilder(int ignoredCapacity)

This implementation does not track capacity; using this constructor is functionally equivalent to using the zero-argument constructor.

StringBuilder

public StringBuilder(String s)

Method Detail

append

public StringBuilder append(boolean x)

append

public StringBuilder append(char x)

Specified by:

append in interface Appendable

append

public StringBuilder append(char[] x)

append

public StringBuilder append(char[] x,
                            int start,
                            int len)

append

public StringBuilder append(CharSequence x)

Specified by:

append in interface Appendable

append

public StringBuilder append(CharSequence x,
                            int start,
                            int end)

Specified by:

append in interface Appendable

append

public StringBuilder append(double x)

append

public StringBuilder append(float x)

append

public StringBuilder append(int x)

append

public StringBuilder append(long x)

append

public StringBuilder append(Object x)

append

public StringBuilder append(String x)

append

public StringBuilder append(StringBuffer x)

appendCodePoint

public StringBuilder appendCodePoint(int x)

capacity

public int capacity()

This implementation does not track capacity; always returns Integer.MAX_VALUE.

charAt

public char charAt(int index)

Specified by:

charAt in interface CharSequence

delete

public StringBuilder delete(int start,
                            int end)

deleteCharAt

public StringBuilder deleteCharAt(int start)

ensureCapacity

public void ensureCapacity(int ignoredCapacity)

This implementation does not track capacity; calling this method has no effect.

getChars

public void getChars(int srcStart,
                     int srcEnd,
                     char[] dst,
                     int dstStart)

indexOf

public int indexOf(String x)

indexOf

public int indexOf(String x,
                   int start)

insert

public StringBuilder insert(int index,
                            boolean x)

insert

public StringBuilder insert(int index,
                            char x)

insert

public StringBuilder insert(int index,
                            char[] x)

insert

public StringBuilder insert(int index,
                            char[] x,
                            int offset,
                            int len)

insert

public StringBuilder insert(int index,
                            CharSequence chars)

insert

public StringBuilder insert(int index,
                            CharSequence chars,
                            int start,
                            int end)

insert

public StringBuilder insert(int index,
                            double x)

insert

public StringBuilder insert(int index,
                            float x)

insert

public StringBuilder insert(int index,
                            int x)

insert

public StringBuilder insert(int index,
                            long x)

insert

public StringBuilder insert(int index,
                            Object x)

insert

public StringBuilder insert(int index,
                            String x)

lastIndexOf

public int lastIndexOf(String s)

lastIndexOf

public int lastIndexOf(String s,
                       int start)

length

public int length()

Specified by:

length in interface CharSequence

replace

public StringBuilder replace(int start,
                             int end,
                             String toInsert)

reverse

public StringBuilder reverse()

setCharAt

public void setCharAt(int index,
                      char x)

Warning! This method is much slower than the JRE implementation. If you need to do character level manipulation, you are strongly advised to use a char[] directly.

setLength

public void setLength(int newLength)

subSequence

public CharSequence subSequence(int start,
                                int end)

Specified by:

subSequence in interface CharSequence

substring

public String substring(int begin)

substring

public String substring(int begin,
                        int end)

toString

public String toString()

Specified by:

toString in interface CharSequence

Overrides:

toString in class Object

trimToSize

public void trimToSize()