OpenJDK 1.22 · java.io.OutputStreamWriter · APIdia, the JavaDoc alternative

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 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. 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(anOutputStream));

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.

Field Summary

Modifier and Type	Field and Description
private final StreamEncoder	se

Inherited from java.io.Writer:: lock

Constructor Summary

Access	Constructor and Description
public	OutputStreamWriter(OutputStream An OutputStream out, String The name of a supported `charset` charsetName) Creates an OutputStreamWriter that uses the named charset.
public	OutputStreamWriter(OutputStream An OutputStream out) Creates an OutputStreamWriter that uses the default character encoding, or where `out` is a `PrintStream`, the charset used by the print stream.
public	OutputStreamWriter(OutputStream An OutputStream out, Charset A charset cs) Creates an OutputStreamWriter that uses the given charset.
public	OutputStreamWriter(OutputStream An OutputStream out, CharsetEncoder A charset encoder enc) Creates an OutputStreamWriter that uses the given charset encoder.

Method Summary

Modifier and Type	Method and Description
public Writer	append(CharSequence The character sequence from which a subsequence will be appended. If `csq` is `null`, then characters will be appended as if `csq` contained the four characters `"null"`. csq, int The index of the first character in the subsequence start, int The index of the character following the last character in the subsequence end) Overrides java.io.Writer.append. Implements java.lang.Appendable.append. Appends a subsequence of the specified character sequence to this writer.
public Writer	append(CharSequence The character sequence to append. If `csq` is `null`, then the four characters `"null"` are appended to this writer. csq) Overrides java.io.Writer.append. Implements java.lang.Appendable.append. Appends the specified character sequence to this writer.
public void	close() Implements abstract java.io.Writer.close. Implements java.io.Closeable.close. Closes the stream, flushing it first.
public void	flush() Implements abstract java.io.Writer.flush. Implements java.io.Flushable.flush. Flushes the stream.
pack-priv void	flushBuffer() Flushes the output buffer to the underlying byte stream, without flushing the byte stream itself.
public String	Returns: The historical name of this encoding, or possibly `null` if the stream has been closed getEncoding() Returns the name of the character encoding being used by this stream.
private static Object	lockFor(OutputStreamWriter writer) Return the lock object for the given writer's stream encoder.
public void	write(int int specifying a character to be written c) Overrides java.io.Writer.write. Writes a single character.
public void	write(char[] Buffer of characters cbuf, int Offset from which to start writing characters off, int Number of characters to write len) Implements abstract java.io.Writer.write. Writes a portion of an array of characters.
public void	write(String A String str, int Offset from which to start writing characters off, int Number of characters to write len) Overrides java.io.Writer.write. Writes a portion of a string.

Inherited from java.io.Writer:: append nullWriter write write

Field Detail

se	back to summary
private final StreamEncoder se

Constructor Detail

OutputStreamWriter back to summary

OutputStreamWriter	back to summary
public OutputStreamWriter(OutputStream out, String charsetName) throws UnsupportedEncodingException Creates an OutputStreamWriter that uses the named charset. Parameters out:OutputStream An OutputStream charsetName:String The name of a supported `charset` Exceptions UnsupportedEncodingException: If the named encoding is not supported

public OutputStreamWriter(OutputStream out, String charsetName) throws UnsupportedEncodingException

Creates an OutputStreamWriter that uses the named charset.

Parameters

out:OutputStream: An OutputStream
charsetName:String: The name of a supported charset

Exceptions

UnsupportedEncodingException:: If the named encoding is not supported

OutputStreamWriter back to summary

OutputStreamWriter	back to summary
public OutputStreamWriter(OutputStream out) Creates an OutputStreamWriter that uses the default character encoding, or where `out` is a `PrintStream`, the charset used by the print stream. Parameters out:OutputStream An OutputStream See Also `Charset#defaultCharset()`

public OutputStreamWriter(OutputStream out)

Creates an OutputStreamWriter that uses the default character encoding, or where out is a PrintStream, the charset used by the print stream.

Parameters

out:OutputStream: An OutputStream

See Also

Charset#defaultCharset()

OutputStreamWriter	back to summary
public OutputStreamWriter(OutputStream out, Charset cs) Creates an OutputStreamWriter that uses the given charset. Parameters out:OutputStream An OutputStream cs:Charset A charset Since 1.4

OutputStreamWriter

back to summary

public OutputStreamWriter(OutputStream out, Charset cs)

Creates an OutputStreamWriter that uses the given charset.

Parameters

out:OutputStream: An OutputStream
cs:Charset: A charset

Since

1.4

OutputStreamWriter	back to summary
public OutputStreamWriter(OutputStream out, CharsetEncoder enc) Creates an OutputStreamWriter that uses the given charset encoder. Parameters out:OutputStream An OutputStream enc:CharsetEncoder A charset encoder Since 1.4

OutputStreamWriter

back to summary

public OutputStreamWriter(OutputStream out, CharsetEncoder enc)

Creates an OutputStreamWriter that uses the given charset encoder.

Parameters

out:OutputStream: An OutputStream
enc:CharsetEncoder: A charset encoder

Since

1.4

Method Detail

append back to summary

append	back to summary
public Writer append(CharSequence csq, int start, int end) throws IOException Overrides java.io.Writer.append. Implements java.lang.Appendable.append. Doc from java.io.Writer.append. Appends a subsequence of the specified character sequence to this writer. `Appendable`. An invocation of this method of the form `out.append(csq, start, end)` when `csq` is not `null` behaves in exactly the same way as the invocation `out.write(csq.subSequence(start, end).toString())` out.write(csq.subSequence(start, end).toString()) Parameters csq:CharSequence The character sequence from which a subsequence will be appended. If `csq` is `null`, then characters will be appended as if `csq` contained the four characters `"null"`. start:int The index of the first character in the subsequence end:int The index of the character following the last character in the subsequence Returns:Writer This writer Annotations @Override Exceptions IOException: If an I/O error occurs

public Writer append(CharSequence csq, int start, int end) throws IOException

Overrides java.io.Writer.append.

Implements java.lang.Appendable.append.

Doc from java.io.Writer.append.

Appends a subsequence of the specified character sequence to this writer. Appendable.

An invocation of this method of the form out.append(csq, start, end) when csq is not null behaves in exactly the same way as the invocation

out.write(csq.subSequence(start, end).toString())

Parameters

csq:CharSequence: The character sequence from which a subsequence will be appended. If csq is null, then characters will be appended as if csq contained the four characters "null".
start:int: The index of the first character in the subsequence
end:int: The index of the character following the last character in the subsequence

Returns:Writer

This writer

Annotations

@Override

Exceptions

IOException:: If an I/O error occurs

append back to summary

append	back to summary
public Writer append(CharSequence csq) throws IOException Overrides java.io.Writer.append. Implements java.lang.Appendable.append. Doc from java.io.Writer.append. Appends the specified character sequence to this writer. An invocation of this method of the form `out.append(csq)` behaves in exactly the same way as the invocation `out.write(csq.toString())` out.write(csq.toString()) Depending on the specification of `toString` for the character sequence `csq`, the entire sequence may not be appended. For instance, invoking the `toString` method of a character buffer will return a subsequence whose content depends upon the buffer's position and limit. Parameters csq:CharSequence The character sequence to append. If `csq` is `null`, then the four characters `"null"` are appended to this writer. Returns:Writer This writer Annotations @Override Exceptions IOException: If an I/O error occurs

public Writer append(CharSequence csq) throws IOException

Overrides java.io.Writer.append.

Implements java.lang.Appendable.append.

Doc from java.io.Writer.append.

Appends the specified character sequence to this writer.

An invocation of this method of the form out.append(csq) behaves in exactly the same way as the invocation

out.write(csq.toString())

Depending on the specification of toString for the character sequence csq, the entire sequence may not be appended. For instance, invoking the toString method of a character buffer will return a subsequence whose content depends upon the buffer's position and limit.

Parameters

csq:CharSequence: The character sequence to append. If csq is null, then the four characters "null" are appended to this writer.

Returns:Writer

This writer

Annotations

@Override

Exceptions

IOException:: If an I/O error occurs

close	back to summary
public void close() throws IOException Implements abstract java.io.Writer.close. Implements java.io.Closeable.close. Doc from java.io.Writer.close. 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. Exceptions IOException: If an I/O error occurs

back to summary

public void close() throws IOException

Implements abstract java.io.Writer.close.

Implements java.io.Closeable.close.

Doc from java.io.Writer.close.

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.

Exceptions

IOException:: If an I/O error occurs

flush	back to summary
public void flush() throws IOException Implements abstract java.io.Writer.flush. Implements java.io.Flushable.flush. Flushes the stream. Exceptions IOException: If an I/O error occurs

flush

back to summary

public void flush() throws IOException

Implements abstract java.io.Writer.flush.

Implements java.io.Flushable.flush.

Flushes the stream.

Exceptions

IOException:: If an I/O error occurs

flushBuffer	back to summary
pack-priv void flushBuffer() throws IOException Flushes 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.

getEncoding back to summary

getEncoding	back to summary
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:String The historical name of this encoding, or possibly `null` if the stream has been closed See Also `Charset`

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

lockFor	back to summary
private static Object lockFor(OutputStreamWriter writer) Return the lock object for the given writer's stream encoder. If the writer type is trusted then an internal lock can be used. If the writer type is not trusted then the writer object is the lock.

write	back to summary
public void write(int c) throws IOException Overrides java.io.Writer.write. Writes a single character. Parameters c:int Doc from java.io.Writer.write. int specifying a character to be written Exceptions IOException: If an I/O error occurs

write

back to summary

public void write(int c) throws IOException

Overrides java.io.Writer.write.

Writes a single character.

Parameters

c:int

Doc from java.io.Writer.write.

int specifying a character to be written

Exceptions

IOException:: If an I/O error occurs

write back to summary

write	back to summary
public void write(char[] cbuf, int off, int len) throws IOException Implements abstract java.io.Writer.write. Writes a portion of an array of characters. Parameters cbuf:char[] Buffer of characters off:int Offset from which to start writing characters len:int Number of characters to write Exceptions IOException: If an I/O error occurs IndexOutOfBoundsException: If `off` is negative, or `len` is negative, or `off + len` is negative or greater than the length of the given array

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

Implements abstract java.io.Writer.write.

Writes a portion of an array of characters.

Parameters

cbuf:char[]: Buffer of characters
off:int: Offset from which to start writing characters
len:int: Number of characters to write

Exceptions

IOException:: If an I/O error occurs
IndexOutOfBoundsException:: If off is negative, or len is negative, or off + len is negative or greater than the length of the given array

write back to summary

write	back to summary
public void write(String str, int off, int len) throws IOException Overrides java.io.Writer.write. Writes a portion of a string. Parameters str:String A String off:int Offset from which to start writing characters len:int Number of characters to write Exceptions IOException: If an I/O error occurs IndexOutOfBoundsException: If `off` is negative, or `len` is negative, or `off + len` is negative or greater than the length of the given string

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

Overrides java.io.Writer.write.

Writes a portion of a string.

Parameters

str:String: A String
off:int: Offset from which to start writing characters
len:int: Number of characters to write

Exceptions

IOException:: If an I/O error occurs
IndexOutOfBoundsException:: If off is negative, or len is negative, or off + len is negative or greater than the length of the given string

public Class OutputStreamWriter

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Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail