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 encoded into bytes using a specified charset. The charset that it uses may be specified by name or may be given explicitly, or the platform's default charset 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 charset then a charset-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
See Also:
BufferedWriter, OutputStream, Charset

 

Field Summary

 
Fields inherited from class java.io.Writer
lock
 

 

Constructor Summary

OutputStreamWriter(OutputStream out)
    Create an OutputStreamWriter that uses the default character encoding.
OutputStreamWriter(OutputStream out, Charset cs)
    Create an OutputStreamWriter that uses the given charset.
OutputStreamWriter(OutputStream out, CharsetEncoder enc)
    Create an OutputStreamWriter that uses the given charset encoder.
OutputStreamWriter(OutputStream out, String charsetName)
    Create an OutputStreamWriter that uses the named charset.
 

 

Method Summary

 void close()
    Close the stream.
 void flush()
    Flush the stream.
 String getEncoding()
    Return the 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 charsetName)
                   throws UnsupportedEncodingException
Create an OutputStreamWriter that uses the named charset.

Parameters:
out - An OutputStream
charsetName - The name of a supported charset
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

public OutputStreamWriter(OutputStream out,
                          Charset cs)
Create an OutputStreamWriter that uses the given charset.

Parameters:
out - An OutputStream
Since:
1.4

 

 

OutputStreamWriter

public OutputStreamWriter(OutputStream out,
                          CharsetEncoder enc)
Create an OutputStreamWriter that uses the given charset encoder.

Parameters:
out - An OutputStream
enc - A charset encoder
Since:
1.4

 

Method Detail

 

 

getEncoding

public String getEncoding()
Return the name of the character encoding being used by this stream.

If the encoding has an historical name then that name is returned; otherwise the encoding's canonical name is returned.

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

Returns:
The historical name of this encoding, or possibly null if the stream has been closed
See Also:
Charset

 

 

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