java.io

Class StringWriter

java.lang.Object

java.io.Writer

java.io.StringWriter

All Implemented Interfaces:

Closeable, Flushable, Appendable, AutoCloseable

public class StringWriter
extends Writer

A specialized Writer that writes characters to a StringBuffer in a sequential manner, appending them in the process. The result can later be queried using the StringWriter(int) or toString() methods.

See Also:

StringReader

Field Summary

Fields inherited from class java.io.Writer

lock

Constructor Summary

Constructors

Constructor and Description
StringWriter() Constructs a new StringWriter which has a StringBuffer allocated with the default size of 16 characters.
StringWriter(int initialSize) Constructs a new StringWriter which has a StringBuffer allocated with a size of initialSize characters.

Method Summary

Modifier and Type	Method and Description
StringWriter	append(char c) Appends the character c to this writer's StringBuffer.
StringWriter	append(CharSequence csq) Appends the character sequence csq to this writer's StringBuffer.
StringWriter	append(CharSequence csq, int start, int end) Appends a subsequence of the character sequence csq to this writer's StringBuffer.
void	close() Calling this method has no effect.
void	flush() Calling this method has no effect.
StringBuffer	getBuffer() Gets a reference to this writer's internal StringBuffer.
String	toString() Gets a copy of the contents of this writer as a string.
void	write(char[] chars, int offset, int count) Writes count characters starting at offset in buf to this writer's StringBuffer.
void	write(int oneChar) Writes one character to this writer's StringBuffer.
void	write(String str) Writes the characters from the specified string to this writer's StringBuffer.
void	write(String str, int offset, int count) Writes count characters from str starting at offset to this writer's StringBuffer.

Methods inherited from class java.io.Writer

nullWriter, write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

StringWriter

public StringWriter()

Constructs a new StringWriter which has a StringBuffer allocated with the default size of 16 characters. The StringBuffer is also the lock used to synchronize access to this writer.

StringWriter

public StringWriter(int initialSize)

Constructs a new StringWriter which has a StringBuffer allocated with a size of initialSize characters. The StringBuffer is also the lock used to synchronize access to this writer.

Parameters:

initialSize - the initial size of the target string buffer.

Method Detail

close

public void close()
           throws IOException

Calling this method has no effect. In contrast to most Writer subclasses, the other methods in StringWriter do not throw an IOException if close() has been called.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Specified by:

close in class Writer

Throws:

IOException - if an error occurs while closing this writer.

flush

public void flush()

Calling this method has no effect.

Specified by:

flush in interface Flushable

Specified by:

flush in class Writer

getBuffer

public StringBuffer getBuffer()

Gets a reference to this writer's internal StringBuffer. Any changes made to the returned buffer are reflected in this writer.

Returns:

a reference to this writer's internal StringBuffer.

toString

public String toString()

Gets a copy of the contents of this writer as a string.

Overrides:

toString in class Object

Returns:

this writer's contents as a string.

write

public void write(char[] chars,
                  int offset,
                  int count)

Writes count characters starting at offset in buf to this writer's StringBuffer.

Specified by:

write in class Writer

Parameters:

chars - the non-null character array to write.

offset - the index of the first character in chars to write.

count - the maximum number of characters to write.

Throws:

IndexOutOfBoundsException - if offset < 0 or count < 0, or if offset + count is greater than the size of buf.

write

public void write(int oneChar)

Writes one character to this writer's StringBuffer. Only the two least significant bytes of the integer oneChar are written.

Overrides:

write in class Writer

Parameters:

oneChar - the character to write to this writer's StringBuffer.

write

public void write(String str)

Writes the characters from the specified string to this writer's StringBuffer.

Overrides:

write in class Writer

Parameters:

str - the non-null string containing the characters to write.

write

public void write(String str,
                  int offset,
                  int count)

Writes count characters from str starting at offset to this writer's StringBuffer.

Overrides:

write in class Writer

Parameters:

str - the non-null string containing the characters to write.

offset - the index of the first character in str to write.

count - the number of characters from str to write.

Throws:

StringIndexOutOfBoundsException - if offset < 0 or count < 0, or if offset + count is greater than the length of str.

append

public StringWriter append(char c)

Appends the character c to this writer's StringBuffer. This method works the same way as write(int).

Specified by:

append in interface Appendable

Overrides:

append in class Writer

Parameters:

c - the character to append to the target stream.

Returns:

this writer.

append

public StringWriter append(CharSequence csq)

Appends the character sequence csq to this writer's StringBuffer. This method works the same way as StringWriter.write(csq.toString()). If csq is null, then the string "null" is written to the target stream.

Specified by:

append in interface Appendable

Overrides:

append in class Writer

Parameters:

csq - the character sequence appended to the target.

Returns:

this writer.

append

public StringWriter append(CharSequence csq,
                           int start,
                           int end)

Appends a subsequence of the character sequence csq to this writer's StringBuffer. This method works the same way as StringWriter.writer(csq.subsequence(start, end).toString()). If csq is null, then the specified subsequence of the string "null" will be written to the target.

Specified by:

append in interface Appendable

Overrides:

append in class Writer

Parameters:

csq - the character sequence appended to the target.

start - the index of the first char in the character sequence appended to the target.

end - the index of the character following the last character of the subsequence appended to the target.

Returns:

this writer.

Throws:

IndexOutOfBoundsException - if start > end, start < 0, end < 0 or either start or end are greater or equal than the length of csq.