java.io
Class OutputStreamWriter

java.lang.Object
  |
  +--java.io.Writer
        |
        +--java.io.OutputStreamWriter

Direct Known Subclasses:

FileWriter

public class OutputStreamWriter

extends Writer

Write characters to an output stream, translating characters into bytes according to a specified character encoding. Each OutputStreamWriter incorporates its own CharToByteConverter, and is thus a bridge from character streams to byte streams.

The encoding used by an OutputStreamWriter may be specified by name, by providing a CharToByteConverter, or by accepting the default encoding, which is defined by the system property file.encoding.

Each invocation of a write() method causes the encoding converter to be invoked on the given character(s). The resulting bytes are accumulated in a buffer before being written to the underlying output stream. The size of this buffer may be specified, but by default it is large enough for most purposes. Note that the characters passed to the write() methods are not buffered. For top efficiency, consider wrapping an OutputStreamWriter within a BufferedWriter so as to avoid frequent converter invocations. For example,

 Writer out
   = new BufferedWriter(new OutputStreamWriter(System.out));
 

Since:

JDK1.1

See Also:

BufferedWriter, OutputStream

Field Summary

private byte[]	bb
private sun.io.CharToByteConverter	ctb
private static int	defaultByteBufferSize
private int	nBytes
private int	nextByte
private OutputStream	out

Fields inherited from class java.io.Writer

lock, writeBuffer, writeBufferSize

Constructor Summary

	OutputStreamWriter(OutputStream out) Create an OutputStreamWriter that uses the default character encoding.
private	OutputStreamWriter(OutputStream out, sun.io.CharToByteConverter ctb) Create an OutputStreamWriter that uses the specified character-to-byte converter.
	OutputStreamWriter(OutputStream out, String enc) Create an OutputStreamWriter that uses the named character encoding.

Method Summary

void	close() Close the stream.
private void	ensureOpen() Check to make sure that the stream has not been closed
void	flush() Flush the stream.
(package private) void	flushBuffer() Flush the output buffer to the underlying byte stream, without flushing the byte stream itself.
String	getEncoding() Returns the canonical name of the character encoding being used by this stream.
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, int off, int len) Write a portion of a string.

Methods inherited from class java.io.Writer

write, write

Methods inherited from class java.lang.Object

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

Field Detail

ctb

private sun.io.CharToByteConverter ctb

out

private OutputStream out

defaultByteBufferSize

private static final int defaultByteBufferSize

bb

private byte[] bb

nextByte

private int nextByte

nBytes

private int nBytes

Constructor Detail

OutputStreamWriter

public OutputStreamWriter(OutputStream out,
                          String enc)
                   throws UnsupportedEncodingException

Create an OutputStreamWriter that uses the named character encoding.

Parameters:

out - An OutputStream

enc - Name of the encoding to be used

Throws:

UnsupportedEncodingException - If the named encoding is not supported

OutputStreamWriter

public OutputStreamWriter(OutputStream out)

Create an OutputStreamWriter that uses the default character encoding.

Parameters:

out - An OutputStream

OutputStreamWriter

private OutputStreamWriter(OutputStream out,
                           sun.io.CharToByteConverter ctb)

Create an OutputStreamWriter that uses the specified character-to-byte converter. The converter is assumed to have been reset.

Parameters:

out - An OutputStream

ctb - A CharToByteConverter

Method Detail

getEncoding

public String getEncoding()

Returns the canonical name of the character encoding being used by this stream. If this OutputStreamWriter was created with the OutputStreamWriter(OutputStream, String) constructor, the returned encoding name, being canonical, may differ from the encoding name passed to the constructor. May return null if the stream has been closed.

ensureOpen

private void ensureOpen()
                 throws IOException

Check to make sure that the stream has not been closed

write

public void write(int c)
           throws IOException

Write a single character.

Throws:

IOException - If an I/O error occurs

Overrides:

write in class Writer

write

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

Write a portion of an array of characters.

Parameters:

cbuf - Buffer of characters

off - Offset from which to start writing characters

len - Number of characters to write

Throws:

IOException - If an I/O error occurs

Overrides:

write in class Writer

write

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

Write a portion of a string.

Parameters:

str - A String

off - Offset from which to start writing characters

len - Number of characters to write

Throws:

IOException - If an I/O error occurs

Overrides:

write in class Writer

flushBuffer

void flushBuffer()
           throws IOException

Flush the output buffer to the underlying byte stream, without flushing the byte stream itself. This method is non-private only so that it may be invoked by PrintStream.

flush

public void flush()
           throws IOException

Flush the stream.

Throws:

IOException - If an I/O error occurs

Overrides:

flush in class Writer

close

public void close()
           throws IOException

Close the stream.

Throws:

IOException - If an I/O error occurs

Overrides:

close in class Writer