Module java.base

Package 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 character stream that collects its output in a string buffer, which can then be used to construct a string.

Closing a StringWriter has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.

Since:

1.1

Field Summary

Fields declared in class java.io.Writer

lock

Constructor Summary

Constructors

Constructor	Description
StringWriter()	Create a new string writer using the default initial string-buffer size.
StringWriter(int initialSize)	Create a new string writer using the specified initial string-buffer size.

Method Summary

Modifier and Type	Method	Description
StringWriter	append(char c)	Appends the specified character to this writer.
StringWriter	append(CharSequence csq)	Appends the specified character sequence to this writer.
StringWriter	append(CharSequence csq, int start, int end)	Appends a subsequence of the specified character sequence to this writer.
void	close()	Closing a StringWriter has no effect.
void	flush()	Flush the stream.
StringBuffer	getBuffer()	Return the string buffer itself.
String	toString()	Return the buffer's current value as a string.
void	write(char[] cbuf, int off, int len)	Write a portion of an array of characters.
void	write(int c)	Write a single character.
void	write(String str)	Write a string.
void	write(String str, int off, int len)	Write a portion of a string.

Methods declared in class java.io.Writer

nullWriter, write

Methods declared in class java.lang.Object

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

Constructor Details

StringWriter

public StringWriter()

Create a new string writer using the default initial string-buffer size.

StringWriter

public StringWriter(int initialSize)

Create a new string writer using the specified initial string-buffer size.

Parameters:

initialSize - The number of char values that will fit into this buffer before it is automatically expanded

Throws:

IllegalArgumentException - If initialSize is negative

Method Details

write

public void write(int c)

Write a single character.

Overrides:

write in class Writer

Parameters:

c - int specifying a character to be written

write

public void write(char[] cbuf,
 int off,
 int len)

Write a portion of an array of characters.

Specified by:

write in class Writer

Parameters:

cbuf - Array of characters

off - Offset from which to start writing characters

len - Number of characters to write

Throws:

IndexOutOfBoundsException - If off is negative, or len is negative, or off + len is negative or greater than the length of the given array

write

public void write(String str)

Write a string.

Overrides:

write in class Writer

Parameters:

str - String to be written

write

public void write(String str,
 int off,
 int len)

Write a portion of a string.

Overrides:

write in class Writer

Parameters:

str - String to be written

off - Offset from which to start writing characters

len - Number of characters to write

Throws:

IndexOutOfBoundsException - If off is negative, or len is negative, or off + len is negative or greater than the length of the given string

append

public StringWriter append(CharSequence csq)

Appends the specified character sequence to this writer.

An invocation of this method of the form out.append(csq) behaves in exactly the same way as the invocation

    out.write(csq.toString())

Depending on the specification of toString for the character sequence csq, the entire sequence may not be appended. For instance, invoking the toString method of a character buffer will return a subsequence whose content depends upon the buffer's position and limit.

Specified by:

append in interface Appendable

Overrides:

append in class Writer

Parameters:

csq - The character sequence to append. If csq is null, then the four characters "null" are appended to this writer.

Returns:

This writer

Since:

1.5

append

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

Appends a subsequence of the specified character sequence to this writer.

An invocation of this method of the form out.append(csq, start, end) when csq is not null, behaves in exactly the same way as the invocation

    out.write(csq.subSequence(start, end).toString())

Specified by:

append in interface Appendable

Overrides:

append in class Writer

Parameters:

csq - The character sequence from which a subsequence will be appended. If csq is null, then characters will be appended as if csq contained the four characters "null".

start - The index of the first character in the subsequence

end - The index of the character following the last character in the subsequence

Returns:

This writer

Throws:

IndexOutOfBoundsException - If start or end are negative, start is greater than end, or end is greater than csq.length()

Since:

1.5

append

public StringWriter append(char c)

Appends the specified character to this writer.

An invocation of this method of the form out.append(c) behaves in exactly the same way as the invocation

    out.write(c)

Specified by:

append in interface Appendable

Overrides:

append in class Writer

Parameters:

c - The 16-bit character to append

Returns:

This writer

Since:

1.5

toString

public String toString()

Return the buffer's current value as a string.

Overrides:

toString in class Object

Returns:

a string representation of the object

getBuffer

public StringBuffer getBuffer()

Return the string buffer itself.

Returns:

StringBuffer holding the current buffer value.

flush

public void flush()

Flush the stream.

The flush method of StringWriter does nothing.

Specified by:

flush in interface Flushable

Specified by:

flush in class Writer

close

public void close()
           throws IOException

Closing a StringWriter has no effect. The methods in this class can be called after the stream has been closed without generating an IOException.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in class Writer

Throws:

IOException - If an I/O error occurs