Class OutputStreamWriter
- java.lang.Object
-
- java.io.Writer
-
- java.io.OutputStreamWriter
- All Implemented Interfaces:
- Closeable, Flushable, Appendable, AutoCloseable
- 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'.
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.
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.
- Since:
- JDK1.1
- See Also:
-
BufferedWriter
,OutputStream
,Charset
Fields
Fields inherited from class java.io.Writer
lock
Constructors
Constructor and Description |
---|
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. |
Methods
Modifier and Type | Method and Description |
---|---|
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
append, append, append, write, write
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Constructors
OutputStreamWriter
public OutputStreamWriter(OutputStream out, String charsetName) throws UnsupportedEncodingException
Creates an OutputStreamWriter that uses the named charset.
- Parameters:
-
out
- An OutputStream -
charsetName
- The name of a supportedcharset
- Throws:
-
UnsupportedEncodingException
- If the named encoding is not supported
OutputStreamWriter
public OutputStreamWriter(OutputStream out)
Creates an OutputStreamWriter that uses the default character encoding.
- Parameters:
-
out
- An OutputStream
OutputStreamWriter
public OutputStreamWriter(OutputStream out, Charset cs)
Creates an OutputStreamWriter that uses the given charset.
- Parameters:
-
out
- An OutputStream -
cs
- A charset - Since:
- 1.4
OutputStreamWriter
public OutputStreamWriter(OutputStream out, CharsetEncoder enc)
Creates an OutputStreamWriter that uses the given charset encoder.
- Parameters:
-
out
- An OutputStream -
enc
- A charset encoder - Since:
- 1.4
Methods
getEncoding
public String getEncoding()
Returns 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
Writes a single character.
- Overrides:
-
write
in classWriter
- 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
Writes a portion of an array of characters.
- Specified by:
-
write
in classWriter
- 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
Writes a portion of a string.
- Overrides:
-
write
in classWriter
- 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
Flushes the stream.
- Specified by:
-
flush
in interfaceFlushable
- Specified by:
-
flush
in classWriter
- Throws:
-
IOException
- If an I/O error occurs
close
public void close() throws IOException
Description copied from class: Writer
Closes the stream, flushing it first. Once the stream has been closed, further write() or flush() invocations will cause an IOException to be thrown. Closing a previously closed stream has no effect.
- Specified by:
-
close
in interfaceCloseable
- Specified by:
-
close
in interfaceAutoCloseable
- Specified by:
-
close
in classWriter
- Throws:
-
IOException
- If an I/O error occurs
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/javase/8/docs/api/java/io/OutputStreamWriter.html