Android
java.lang
public final class

java.lang.StringBuffer

java.lang.Object
java.lang.StringBuffer Serializable Appendable CharSequence

StringBuffer is a variable size contiguous indexable array of characters. The length of the StringBuffer is the number of characters it contains. The capacity of the StringBuffer is the number of characters it can hold.

Characters may be inserted at any position up to the length of the StringBuffer, increasing the length of the StringBuffer. Characters at any position in the StringBuffer may be replaced, which does not affect the StringBuffer length.

The capacity of a StringBuffer may be specified when the StringBuffer is created. If the capacity of the StringBuffer is exceeded, the capacity is increased.

Summary

Public Constructors

            StringBuffer()
Constructs a new StringBuffer using the default capacity.
            StringBuffer(int capacity)
Constructs a new StringBuffer using the specified capacity.
            StringBuffer(String string)
Constructs a new StringBuffer containing the characters in the specified string and the default capacity.
            StringBuffer(CharSequence cs)

Constructs a StringBuffer and initializes it with the characters in the CharSequence.

Public Methods

          StringBuffer  append(double d)
Adds the string representation of the specified double to the end of this StringBuffer.
  synchronized        StringBuffer  append(CharSequence s)

Appends the CharSequence to this buffer.

          StringBuffer  append(long l)
Adds the string representation of the specified long to the end of this StringBuffer.
          StringBuffer  append(int i)
Adds the string representation of the specified integer to the end of this StringBuffer.
          StringBuffer  append(boolean b)
Adds the string representation of the specified boolean to the end of this StringBuffer.
  synchronized        StringBuffer  append(Object obj)
Adds the string representation of the specified object to the end of this StringBuffer.
  synchronized        StringBuffer  append(char ch)
Adds the specified character to the end of this StringBuffer.
  synchronized        StringBuffer  append(char[] chars)
Adds the character array to the end of this StringBuffer.
  synchronized        StringBuffer  append(String string)
Adds the specified string to the end of this StringBuffer.
          StringBuffer  append(float f)
Adds the string representation of the specified float to the end of this StringBuffer.
  synchronized        StringBuffer  append(char[] chars, int start, int length)
Adds the specified sequence of characters to the end of this StringBuffer.
  synchronized        StringBuffer  append(CharSequence s, int start, int end)

Appends the subsequence of the CharSequence to this buffer.

  synchronized        StringBuffer  append(StringBuffer sb)
Adds the specified StringBuffer to the end of this StringBuffer.
          StringBuffer  appendCodePoint(int codePoint)

Appends the encoded Unicode code point to this object.

          int  capacity()
Returns the number of characters this StringBuffer can hold without growing.
  synchronized        char  charAt(int index)
Returns the character at the specified offset in this StringBuffer.
  synchronized        int  codePointAt(int index)

Retrieves the Unicode code point value at the index.

  synchronized        int  codePointBefore(int index)

Retrieves the Unicode code point value that precedes the index.

  synchronized        int  codePointCount(int beginIndex, int endIndex)

Calculates the number of Unicode code points between beginIndex and endIndex.

  synchronized        StringBuffer  delete(int start, int end)
Deletes a range of characters.
  synchronized        StringBuffer  deleteCharAt(int location)
Deletes a single character
  synchronized        void  ensureCapacity(int min)
Ensures that this StringBuffer can hold the specified number of characters without growing.
  synchronized        void  getChars(int start, int end, char[] buffer, int idx)
Copies the specified characters in this StringBuffer to the character array starting at the specified offset in the character array.
  synchronized        int  indexOf(String subString, int start)
Searches in this StringBuffer for the index of the specified character.
          int  indexOf(String string)
Searches in this StringBuffer for the first index of the specified character.
          StringBuffer  insert(int index, Object obj)
Inserts the string representation of the specified object at the specified offset in this StringBuffer.
  synchronized        StringBuffer  insert(int index, String string)
Inserts the string at the specified offset in this StringBuffer.
  synchronized        StringBuffer  insert(int index, char[] chars)
Inserts the character array at the specified offset in this StringBuffer.
          StringBuffer  insert(int index, boolean b)
Inserts the string representation of the specified boolean at the specified offset in this StringBuffer.
          StringBuffer  insert(int index, double d)
Inserts the string representation of the specified double at the specified offset in this StringBuffer.
  synchronized        StringBuffer  insert(int index, char ch)
Inserts the character at the specified offset in this StringBuffer.
          StringBuffer  insert(int index, float f)
Inserts the string representation of the specified float at the specified offset in this StringBuffer.
          StringBuffer  insert(int index, int i)
Inserts the string representation of the specified integer at the specified offset in this StringBuffer.
  synchronized        StringBuffer  insert(int index, CharSequence s)

Inserts the CharSequence into this buffer at the index.

  synchronized        StringBuffer  insert(int index, CharSequence s, int start, int end)

Inserts the CharSequence into this buffer at the index.

  synchronized        StringBuffer  insert(int index, char[] chars, int start, int length)
Inserts the specified sequence of characters at the specified offset in this StringBuffer.
          StringBuffer  insert(int index, long l)
Inserts the string representation of the specified long at the specified offset in this StringBuffer.
          int  lastIndexOf(String string)
Searches in this StringBuffer for the last index of the specified character.
  synchronized        int  lastIndexOf(String subString, int start)
Searches in this StringBuffer for the index of the specified character.
          int  length()

The current length of this object.

  synchronized        int  offsetByCodePoints(int index, int codePointOffset)

Returns the index within this object that is offset from index by codePointOffset code points.

  synchronized        StringBuffer  replace(int start, int end, String string)
Replace a range of characters with the characters in the specified String.
  synchronized        StringBuffer  reverse()
Reverses the order of characters in this StringBuffer.
  synchronized        void  setCharAt(int index, char ch)
Sets the character at the specified offset in this StringBuffer.
  synchronized        void  setLength(int length)
Sets the length of this StringBuffer to the specified length.
  synchronized        CharSequence  subSequence(int start, int end)
Copies a range of characters into a new String.
  synchronized        String  substring(int start, int end)
Copies a range of characters into a new String.
  synchronized        String  substring(int start)
Copies a range of characters into a new String.
  synchronized        String  toString()
Returns the contents of this StringBuffer.
  synchronized        void  trimToSize()

Trims the storage capacity of this buffer down to the size of the current character sequence.

Methods inherited from class java.lang.Object
Methods inherited from interface java.lang.Appendable
Methods inherited from interface java.lang.CharSequence

Details

Public Constructors

public StringBuffer()

Constructs a new StringBuffer using the default capacity.

public StringBuffer(int capacity)

Constructs a new StringBuffer using the specified capacity.

Parameters

capacity the initial capacity

public StringBuffer(String string)

Constructs a new StringBuffer containing the characters in the specified string and the default capacity.

Parameters

string the string content with which to initialize the new StringBuffer instance

Throws

NullPointerException on supplying a null value of string

public StringBuffer(CharSequence cs)

Constructs a StringBuffer and initializes it with the characters in the CharSequence.

Parameters

cs The CharSequence to initialize the instance.

Throws

NullPointerException if the cs parameter is null.

Public Methods

public StringBuffer append(double d)

Adds the string representation of the specified double to the end of this StringBuffer.

Parameters

d the double

Returns

  • this StringBuffer

public synchronized StringBuffer append(CharSequence s)

Appends the CharSequence to this buffer. If the CharSequence is null, then the string "null" is appended.

Parameters

s The CharSequence to append.

Returns

  • A reference to this object.

public StringBuffer append(long l)

Adds the string representation of the specified long to the end of this StringBuffer.

Parameters

l the long

Returns

  • this StringBuffer

public StringBuffer append(int i)

Adds the string representation of the specified integer to the end of this StringBuffer.

Parameters

i the integer

Returns

  • this StringBuffer

public StringBuffer append(boolean b)

Adds the string representation of the specified boolean to the end of this StringBuffer.

Parameters

b the boolean

Returns

  • this StringBuffer

public synchronized StringBuffer append(Object obj)

Adds the string representation of the specified object to the end of this StringBuffer.

Parameters

obj the object

Returns

  • this StringBuffer

public synchronized StringBuffer append(char ch)

Adds the specified character to the end of this StringBuffer.

Parameters

ch a character

Returns

  • this StringBuffer

public synchronized StringBuffer append(char[] chars)

Adds the character array to the end of this StringBuffer.

Parameters

chars the character array

Returns

  • this StringBuffer

Throws

NullPointerException when chars is null

public synchronized StringBuffer append(String string)

Adds the specified string to the end of this StringBuffer.

Parameters

string the string

Returns

  • this StringBuffer

public StringBuffer append(float f)

Adds the string representation of the specified float to the end of this StringBuffer.

Parameters

f the float

Returns

  • this StringBuffer

public synchronized StringBuffer append(char[] chars, int start, int length)

Adds the specified sequence of characters to the end of this StringBuffer.

Parameters

chars a character array
start the starting offset
length the number of characters

Returns

  • this StringBuffer

Throws

ArrayIndexOutOfBoundsException when length < 0, start < 0 or start + length > chars.length
NullPointerException when chars is null

public synchronized StringBuffer append(CharSequence s, int start, int end)

Appends the subsequence of the CharSequence to this buffer. If the CharSequence is null, then the string "null" is used to extract a subsequence.

Parameters

s The CharSequence to append.
start The inclusive start index of the subsequence of the CharSequence.
end The exclusive end index of the subsequence of the CharSequence.

Returns

  • A reference to this object.

Throws

IndexOutOfBoundsException if start or end are negative, start is greater than end or end is greater than the length of s.

public synchronized StringBuffer append(StringBuffer sb)

Adds the specified StringBuffer to the end of this StringBuffer.

Parameters

sb the StringBuffer

Returns

  • this StringBuffer

public StringBuffer appendCodePoint(int codePoint)

Appends the encoded Unicode code point to this object. The code point is converted to a char[] as defined by toChars(int).

Parameters

codePoint The Unicode code point to encode and append.

Returns

  • A reference to this object.

See Also

public int capacity()

Returns the number of characters this StringBuffer can hold without growing.

Returns

  • the capacity of this StringBuffer

public synchronized char charAt(int index)

Returns the character at the specified offset in this StringBuffer.

Parameters

index the zero-based index in this StringBuffer

Returns

  • the character at the index

Throws

IndexOutOfBoundsException when index < 0 or index >= length()

public synchronized int codePointAt(int index)

Retrieves the Unicode code point value at the index.

Parameters

index The index to the char code unit within this object.

Returns

  • The Unicode code point value.

Throws

IndexOutOfBoundsException if index is negative or greater than or equal to length().

public synchronized int codePointBefore(int index)

Retrieves the Unicode code point value that precedes the index.

Parameters

index The index to the char code unit within this object.

Returns

  • The Unicode code point value.

Throws

IndexOutOfBoundsException if index is less than 1 or greater than length().

public synchronized int codePointCount(int beginIndex, int endIndex)

Calculates the number of Unicode code points between beginIndex and endIndex.

Parameters

beginIndex The inclusive beginning index of the subsequence.
endIndex The exclusive end index of the subsequence.

Returns

  • The number of Unicode code points in the subsequence.

Throws

IndexOutOfBoundsException if beginIndex is negative or greater than endIndex or endIndex is greater than length().

public synchronized StringBuffer delete(int start, int end)

Deletes a range of characters.

Parameters

start the offset of the first character
end the offset one past the last character

Returns

  • this StringBuffer

Throws

StringIndexOutOfBoundsException when start < 0, start > end or end > length()

public synchronized StringBuffer deleteCharAt(int location)

Deletes a single character

Parameters

location the offset of the character to delete

Returns

  • this StringBuffer

Throws

StringIndexOutOfBoundsException when location < 0 or location >= length()

public synchronized void ensureCapacity(int min)

Ensures that this StringBuffer can hold the specified number of characters without growing.

Parameters

min the minimum number of elements that this StringBuffer will hold before growing

public synchronized void getChars(int start, int end, char[] buffer, int idx)

Copies the specified characters in this StringBuffer to the character array starting at the specified offset in the character array.

Parameters

start the starting offset of characters to copy
end the ending offset of characters to copy
buffer the destination character array
idx the starting offset in the character array

Throws

IndexOutOfBoundsException when start < 0, end > length(), start > end, index < 0, end - start > buffer.length - index
NullPointerException when buffer is null

public synchronized int indexOf(String subString, int start)

Searches in this StringBuffer for the index of the specified character. The search for the character starts at the specified offset and moves towards the end.

Parameters

subString the string to find
start the starting offset

Returns

  • the index in this StringBuffer of the specified character, -1 if the character isn't found

public int indexOf(String string)

Searches in this StringBuffer for the first index of the specified character. The search for the character starts at the beginning and moves towards the end.

Parameters

string the string to find

Returns

  • the index in this StringBuffer of the specified character, -1 if the character isn't found

public StringBuffer insert(int index, Object obj)

Inserts the string representation of the specified object at the specified offset in this StringBuffer.

Parameters

index the index at which to insert
obj the object to insert

Returns

  • this StringBuffer

Throws

StringIndexOutOfBoundsException when index < 0 or index > length()

public synchronized StringBuffer insert(int index, String string)

Inserts the string at the specified offset in this StringBuffer.

Parameters

index the index at which to insert
string the string to insert

Returns

  • this StringBuffer

Throws

StringIndexOutOfBoundsException when index < 0 or index > length()

public synchronized StringBuffer insert(int index, char[] chars)

Inserts the character array at the specified offset in this StringBuffer.

Parameters

index the index at which to insert
chars the character array to insert

Returns

  • this StringBuffer

Throws

StringIndexOutOfBoundsException when index < 0 or index > length()
NullPointerException when chars is null

public StringBuffer insert(int index, boolean b)

Inserts the string representation of the specified boolean at the specified offset in this StringBuffer.

Parameters

index the index at which to insert
b the boolean to insert

Returns

  • this StringBuffer

Throws

StringIndexOutOfBoundsException when index < 0 or index > length()

public StringBuffer insert(int index, double d)

Inserts the string representation of the specified double at the specified offset in this StringBuffer.

Parameters

index the index at which to insert
d the double to insert

Returns

  • this StringBuffer

Throws

StringIndexOutOfBoundsException when index < 0 or index > length()

public synchronized StringBuffer insert(int index, char ch)

Inserts the character at the specified offset in this StringBuffer.

Parameters

index the index at which to insert
ch the character to insert

Returns

  • this StringBuffer

Throws

ArrayIndexOutOfBoundsException when index < 0 or index > length()

public StringBuffer insert(int index, float f)

Inserts the string representation of the specified float at the specified offset in this StringBuffer.

Parameters

index the index at which to insert
f the float to insert

Returns

  • this StringBuffer

Throws

StringIndexOutOfBoundsException when index < 0 or index > length()

public StringBuffer insert(int index, int i)

Inserts the string representation of the specified integer at the specified offset in this StringBuffer.

Parameters

index the index at which to insert
i the integer to insert

Returns

  • this StringBuffer

Throws

StringIndexOutOfBoundsException when index < 0 or index > length()

public synchronized StringBuffer insert(int index, CharSequence s)

Inserts the CharSequence into this buffer at the index. If CharSequence is null, then the string "null" is inserted.

Parameters

index The index of this buffer to insert the sequence.
s The CharSequence to insert.

Returns

  • A reference to this object.

Throws

IndexOutOfBoundsException if the index is invalid.

public synchronized StringBuffer insert(int index, CharSequence s, int start, int end)

Inserts the CharSequence into this buffer at the index. If CharSequence is null, then the string "null" is inserted.

Parameters

index The index of this buffer to insert the sequence.
s The CharSequence to insert.
start The inclusive start index of the subsequence of the CharSequence.
end The exclusive end index of the subsequence of the CharSequence.

Returns

  • A reference to this object.

Throws

IndexOutOfBoundsException if index is negative or greater than the current length, start or end are negative, start is greater than end or end is greater than the length of s.

public synchronized StringBuffer insert(int index, char[] chars, int start, int length)

Inserts the specified sequence of characters at the specified offset in this StringBuffer.

Parameters

index the index at which to insert
chars a character array
start the starting offset
length the number of characters

Returns

  • this StringBuffer

Throws

StringIndexOutOfBoundsException when length < 0, start < 0, start + length > chars.length, index < 0 or index > length()
NullPointerException when chars is null

public StringBuffer insert(int index, long l)

Inserts the string representation of the specified long at the specified offset in this StringBuffer.

Parameters

index the index at which to insert
l the long to insert

Returns

  • this StringBuffer

Throws

StringIndexOutOfBoundsException when index < 0 or index > length()

public int lastIndexOf(String string)

Searches in this StringBuffer for the last index of the specified character. The search for the character starts at the end and moves towards the beginning.

Parameters

string the string to find

Returns

  • the index in this StringBuffer of the specified character, -1 if the character isn't found

Throws

NullPointerException if the string parameter is null.

public synchronized int lastIndexOf(String subString, int start)

Searches in this StringBuffer for the index of the specified character. The search for the character starts at the specified offset and moves towards the beginning.

Parameters

subString the string to find
start the starting offset

Returns

  • the index in this StringBuffer of the specified character, -1 if the character isn't found

public int length()

The current length of this object.

Returns

  • the number of characters in this StringBuffer

public synchronized int offsetByCodePoints(int index, int codePointOffset)

Returns the index within this object that is offset from index by codePointOffset code points.

Parameters

index The index within this object to calculate the offset from.
codePointOffset The number of code points to count.

Returns

  • The index within this object that is the offset.

Throws

IndexOutOfBoundsException if index is negative or greater than length() or if there aren't enough code points before or after index to match codePointOffset.

public synchronized StringBuffer replace(int start, int end, String string)

Replace a range of characters with the characters in the specified String.

Parameters

start the offset of the first character
end the offset one past the last character
string a String

Returns

  • this StringBuffer

Throws

StringIndexOutOfBoundsException when start < 0 or start > end

public synchronized StringBuffer reverse()

Reverses the order of characters in this StringBuffer.

Returns

  • this StringBuffer

public synchronized void setCharAt(int index, char ch)

Sets the character at the specified offset in this StringBuffer.

Parameters

index the zero-based index in this StringBuffer
ch the character

Throws

IndexOutOfBoundsException when index < 0 or index >= length()

public synchronized void setLength(int length)

Sets the length of this StringBuffer to the specified length. If there are more than length characters in this StringBuffer, the characters at end are lost. If there are less than length characters in the StringBuffer, the additional characters are set to \\u0000.

Parameters

length the new length of this StringBuffer

Throws

IndexOutOfBoundsException when length < 0

See Also

public synchronized CharSequence subSequence(int start, int end)

Copies a range of characters into a new String.

Parameters

start the offset of the first character
end the offset one past the last character

Returns

  • a new String containing the characters from start to end - 1

Throws

IndexOutOfBoundsException when start < 0, start > end or end > length()

public synchronized String substring(int start, int end)

Copies a range of characters into a new String.

Parameters

start the offset of the first character
end the offset one past the last character

Returns

  • a new String containing the characters from start to end - 1

Throws

StringIndexOutOfBoundsException when start < 0, start > end or end > length()

public synchronized String substring(int start)

Copies a range of characters into a new String.

Parameters

start the offset of the first character

Returns

  • a new String containing the characters from start to the end of the string

Throws

StringIndexOutOfBoundsException when start < 0 or start > length()

public synchronized String toString()

Returns the contents of this StringBuffer.

Returns

  • a String containing the characters in this StringBuffer

public synchronized void trimToSize()

Trims the storage capacity of this buffer down to the size of the current character sequence. Execution of this method may change the results returned by the capacity() method, but this is not required.

Copyright 2007 Google Inc. Build 0.9_r1-98467 - 14 Aug 2008 18:48