java.io

Class OutputStreamWriter

java.lang.Object

java.io.Writer

java.io.OutputStreamWriter

Direct Known Subclasses:

FileWriter

public class OutputStreamWriter
extends Writer

An OutputStreamWriter is a bridge from character streams to byte streams: Characters written to it are translated into bytes according to a specified character encoding. The encoding that it uses may be specified by name, or the platform's default encoding may be accepted.

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));
 

A surrogate pair is a character represented by a sequence of two char values: A high surrogate in the range '\uD800' to '\uDBFF' followed by a low surrogate in the range '\uDC00' to '\uDFFF'. If the character represented by a surrogate pair cannot be encoded by a given encoding then a encoding-dependent substitution sequence is written to the output stream.

A malformed surrogate element is a high surrogate that is not followed by a low surrogate or a low surrogate that is not preceeded by a high surrogate. It is illegal to attempt to write a character stream containing malformed surrogate elements. The behavior of an instance of this class when a malformed surrogate element is written is not specified.

Since:

JDK1.1

Version:

1.28, 02/02/00

Author:

Mark Reinhold

See Also:

BufferedWriter, OutputStream, Character encodings

Field Summary

Fields inherited from class java.io.Writer

lock

Constructor Summary

Constructors

Constructor and Description
OutputStreamWriter(OutputStream out) Create an OutputStreamWriter that uses the default character encoding.
OutputStreamWriter(OutputStream out, String enc) Create an OutputStreamWriter that uses the named character encoding.

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Close the stream.
void	flush() Flush the stream.
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, toString, wait, wait, wait

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 - The name of a supported character encoding

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

Method Detail

getEncoding

public String getEncoding()

Returns the canonical name of the character encoding being used by this stream.

If this instance was created with the OutputStreamWriter(OutputStream, String) constructor then the returned encoding name, being canonical, may differ from the encoding name passed to the constructor. This method may return null if the stream has been closed.

NOTE : In J2ME CDC, there is no concept of historical name, so only canonical name of character encoding is returned. For a list of acceptable canonical names of the character encoding see: http://java.sun.com/j2se/1.4.2/docs/guide/intl/encoding.doc.html

Returns:

a String representing the encoding name, or possibly null if the stream has been closed

See Also:

Character encodings

write

public void write(int c)
           throws IOException

Write a single character.

Overrides:

write in class Writer

Parameters:

c - int specifying a character to be written.

Throws:

IOException - If an I/O error occurs

write

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

Write a portion of an array of characters.

Specified by:

write in class Writer

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

write

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

Write a portion of a string.

Overrides:

write in class Writer

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

flush

public void flush()
           throws IOException

Flush the stream.

Specified by:

flush in class Writer

Throws:

IOException - If an I/O error occurs

close

public void close()
           throws IOException

Close the stream.

Specified by:

close in class Writer

Throws:

IOException - If an I/O error occurs