StringBuffer class « StringBuffer « Character String « Development

Java manipulate StringBuffers behind the scenes when you are using the overloaded + operator.

Create StringBuffer object

Constructor	Summary
StringBuffer()	Creates a string buffer with no characters in it and an initial capacity of 16 characters.
StringBuffer(CharSequence seq)	Creates a string buffer that contains the same characters as the specified CharSequence.
StringBuffer(int capacity)	Creates a string buffer with no characters in it and the specified initial capacity.
StringBuffer(String str)	Creates a string buffer initialized to the contents of the specified string.

Append data to the end of a StringBuffer

Return	Method	Summary
StringBuffer	append(boolean b)	Appends the boolean argument to the sequence.
StringBuffer	append(char c)	Appends the char argument to this sequence.
StringBuffer	append(char[] str)	Appends the char array argument to this sequence.
StringBuffer	append(char[] str, int offset, int len)	Appends a subarray of the char array argument to this sequence.
StringBuffer	append(CharSequence s)	Appends the CharSequence to this sequence.
StringBuffer	append(CharSequence s, int start, int end)	Appends a subsequence of the CharSequence to this sequence.
StringBuffer	append(double d)	Appends the double argument to this sequence.
StringBuffer	append(float f)	Appends the float argument to this sequence.
StringBuffer	append(int i)	Appends the int argument to this sequence.
StringBuffer	append(long lng)	Appends the long argument to this sequence.
StringBuffer	append(Object obj)	Appends the Object argument.
StringBuffer	append(String str)	Appends this character sequence.
StringBuffer	append(StringBuffer sb)	Appends the StringBuffer to this sequence.
StringBuffer	appendCodePoint(int codePoint)	Appends the codePoint argument to this sequence.
StringBuffer	insert(int offset, boolean b)	Inserts the boolean argument into this sequence.
StringBuffer	insert(int offset, char c)	Inserts the char argument into this sequence.
StringBuffer	insert(int offset, char[] str)	Inserts the char array argument into this sequence.
StringBuffer	insert(int index, char[] str, int offset, int len)	Inserts a subarray of the str array argument into this sequence.
StringBuffer	insert(int dstOffset, CharSequence s)	Inserts CharSequence into this sequence.
StringBuffer	insert(int dstOffset, CharSequence s, int start, int end)	Inserts a subsequence of the specified CharSequence into this sequence.
StringBuffer	insert(int offset, double d)	Inserts the double argument into this sequence.
StringBuffer	insert(int offset, float f)	Inserts the float argument into this sequence.
StringBuffer	insert(int offset, int i)	Inserts the second int argument into this sequence.
StringBuffer	insert(int offset, long l)	Inserts the long argument into this sequence.
StringBuffer	insert(int offset, Object obj)	Inserts the Object argument into this character sequence.
StringBuffer	insert(int offset, String str)	Inserts str.

Delete or replace or reverse a StringBuffer

Return	Method	Summary
StringBuffer	delete(int start, int end)	Removes the characters in a substring of this sequence.
StringBuffer	deleteCharAt(int index)	Removes the char at the specified position in this sequence.
StringBuffer	replace(int start, int end, String str)	Replaces the characters in a substring of this sequence with characters in the specified String.
StringBuffer	reverse()	Causes this character sequence to be replaced by the reverse of the sequence.

Capacity and length

Return	Method	Summary
int	capacity()	Returns the current capacity.
int	length()	Returns the length (character count).
void	ensureCapacity(int minimumCapacity)	Ensures that the capacity is at least equal to the specified minimum.
void	setLength(int newLength)	Sets the length of the character sequence.
void	trimToSize()	Attempts to reduce storage used for the character sequence.

Char index

Return	Method	Summary
char	charAt(int index)	Returns the char value in this sequence at the specified index.
void	setCharAt(int index, char ch)	The character at the specified index is set to ch.
void	getChars(int srcBegin, int srcEnd, char[] dst, int dstBegin)	Characters are copied from this sequence into the destination character array dst.
int	indexOf(String str)	Returns the index within this string of the first occurrence of the specified substring.
int	indexOf(String str, int fromIndex)	Returns the index within this string of the first occurrence of the specified substring, starting at the specified index.
int	lastIndexOf(String str)	Returns the index within this string of the rightmost occurrence of the specified substring.
int	lastIndexOf(String str, int fromIndex)	Returns the index within this string of the last occurrence of the specified substring.

Convert StringBuffer to String

Return	Method	Summary
String	substring(int start)	Returns a new String that contains a subsequence of characters currently contained in this character sequence.
String	substring(int start, int end)	Returns a new String that contains a subsequence of characters currently contained in this sequence.
String	toString()	Returns a string representing the data in this sequence.
CharSequence	subSequence(int start, int end)	Returns a new character sequence that is a subsequence of this sequence.

StringBuffer class

What is StringBuffer