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.
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();
}
}