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/*
* Copyright (c) 1996, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.io;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
import sun.nio.cs.StreamEncoder;
/**
* An OutputStreamWriter is a bridge from character streams to byte streams:
* Characters written to it are encoded into bytes using a specified {@link
* java.nio.charset.Charset 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 {@linkplain java.nio.charset.CharsetEncoder} class should be used when more
* control over the encoding process is required.
*
* @see BufferedWriter
* @see OutputStream
* @see java.nio.charset.Charset
*
* @author Mark Reinhold
* @since JDK1.1
*/
public class OutputStreamWriter extends Writer {
private final StreamEncoder se;
/**
* Creates an OutputStreamWriter that uses the named charset.
*
* @param out
* An OutputStream
*
* @param charsetName
* The name of a supported
* {@link java.nio.charset.Charset charset}
*
* @exception UnsupportedEncodingException
* If the named encoding is not supported
*/
public OutputStreamWriter(OutputStream out, String charsetName)
throws UnsupportedEncodingException
{
super(out);
if (charsetName == null)
throw new NullPointerException("charsetName");
se = StreamEncoder.forOutputStreamWriter(out, this, charsetName);
}
/**
* Creates an OutputStreamWriter that uses the default character encoding.
*
* @param out An OutputStream
*/
public OutputStreamWriter(OutputStream out) {
super(out);
try {
se = StreamEncoder.forOutputStreamWriter(out, this, (String)null);
} catch (UnsupportedEncodingException e) {
throw new Error(e);
}
}
/**
* Creates an OutputStreamWriter that uses the given charset.
*
* @param out
* An OutputStream
*
* @param cs
* A charset
*
* @since 1.4
* @spec JSR-51
*/
public OutputStreamWriter(OutputStream out, Charset cs) {
super(out);
if (cs == null)
throw new NullPointerException("charset");
se = StreamEncoder.forOutputStreamWriter(out, this, cs);
}
/**
* Creates an OutputStreamWriter that uses the given charset encoder.
*
* @param out
* An OutputStream
*
* @param enc
* A charset encoder
*
* @since 1.4
* @spec JSR-51
*/
public OutputStreamWriter(OutputStream out, CharsetEncoder enc) {
super(out);
if (enc == null)
throw new NullPointerException("charset encoder");
se = StreamEncoder.forOutputStreamWriter(out, this, enc);
}
/**
* 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 {@link
* #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.
*
* @return The historical name of this encoding, or possibly
* null if the stream has been closed
*
* @see java.nio.charset.Charset
*
* @revised 1.4
* @spec JSR-51
*/
public String getEncoding() {
return se.getEncoding();
}
/**
* 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.
*/
void flushBuffer() throws IOException {
se.flushBuffer();
}
/**
* Writes a single character.
*
* @exception IOException If an I/O error occurs
*/
public void write(int c) throws IOException {
se.write(c);
}
/**
* Writes a portion of an array of characters.
*
* @param cbuf Buffer of characters
* @param off Offset from which to start writing characters
* @param len Number of characters to write
*
* @exception IOException If an I/O error occurs
*/
public void write(char cbuf[], int off, int len) throws IOException {
se.write(cbuf, off, len);
}
/**
* Writes a portion of a string.
*
* @param str A String
* @param off Offset from which to start writing characters
* @param len Number of characters to write
*
* @exception IOException If an I/O error occurs
*/
public void write(String str, int off, int len) throws IOException {
se.write(str, off, len);
}
/**
* Flushes the stream.
*
* @exception IOException If an I/O error occurs
*/
public void flush() throws IOException {
se.flush();
}
public void close() throws IOException {
se.close();
}
}