java.lang.Objectjava.io.Writer
java.io.OutputStreamWriter
public class OutputStreamWriter
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 preceded 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.
This class always replaces malformed surrogate elements and unmappable character sequences with the charset's default
substitution sequence
. The
CharsetEncoder
class should be used when more control over the encoding process is required.
Field Summary |
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Fields inherited from class java.io. Writer |
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lock |
Constructor Summary | |
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OutputStreamWriter
(
OutputStream
out) Creates an OutputStreamWriter that uses the default character encoding. |
|
OutputStreamWriter
(
OutputStream
out,
Charset
cs) Creates an OutputStreamWriter that uses the given charset. |
|
OutputStreamWriter
(
OutputStream
out,
CharsetEncoder
enc) Creates an OutputStreamWriter that uses the given charset encoder. |
|
OutputStreamWriter
(
OutputStream
out,
String
charsetName) Creates an OutputStreamWriter that uses the named charset. |
Method Summary | |
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void |
close
() Closes the stream, flushing it first. |
void |
flush
() Flushes the stream. |
String |
getEncoding
() Returns the name of the character encoding being used by this stream. |
void |
write
(char[] cbuf, int off, int len) Writes a portion of an array of characters. |
void |
write
(int c) Writes a single character. |
void |
write
(
String
str, int off, int len) Writes a portion of a string. |
Methods inherited from class java.io. Writer |
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append , append , append , write , write |
Methods inherited from class java.lang. Object |
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clone , equals , finalize , getClass , hashCode , notify , notifyAll , toString , wait , wait , wait |
Constructor Detail |
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public OutputStreamWriter(OutputStream out, String charsetName) throws UnsupportedEncodingException
public OutputStreamWriter(OutputStream out)
public OutputStreamWriter(OutputStream out, Charset cs)
public OutputStreamWriter(OutputStream out, CharsetEncoder enc)
Method Detail |
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public String getEncoding()
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.
public void write(int c) throws IOException
public void write(char[] cbuf, int off, int len) throws IOException
public void write(String str, int off, int len) throws IOException
public void flush() throws IOException
public void close() throws IOException