/*
 * Copyright (c) 2002-2017, the original author or authors.
 *
 * This software is distributable under the BSD license. See the terms of the
 * BSD license in the documentation provided with this software.
 *
 * http://www.opensource.org/licenses/bsd-license.php
 */
package jdk.internal.org.jline.utils;

import java.io.IOException;
import java.io.OutputStream;
import java.io.Writer;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CoderResult;
import java.nio.charset.CodingErrorAction;

Redirects an OutputStream to a Writer by decoding the data using the specified Charset.

Note: This class should only be used if it is necessary to redirect an OutputStream to a Writer for compatibility purposes. It is much more efficient to write to the Writer directly.

/** * Redirects an {@link OutputStream} to a {@link Writer} by decoding the data * using the specified {@link Charset}. * * <p><b>Note:</b> This class should only be used if it is necessary to * redirect an {@link OutputStream} to a {@link Writer} for compatibility * purposes. It is much more efficient to write to the {@link Writer} * directly.</p> */
public class WriterOutputStream extends OutputStream { private final Writer out; private final CharsetDecoder decoder; private final ByteBuffer decoderIn = ByteBuffer.allocate(256); private final CharBuffer decoderOut = CharBuffer.allocate(128); public WriterOutputStream(Writer out, Charset charset) { this(out, charset.newDecoder() .onMalformedInput(CodingErrorAction.REPLACE) .onUnmappableCharacter(CodingErrorAction.REPLACE)); } public WriterOutputStream(Writer out, CharsetDecoder decoder) { this.out = out; this.decoder = decoder; } @Override public void write(int b) throws IOException { write(new byte[] { (byte)b }, 0, 1); } @Override public void write(byte[] b) throws IOException { write(b, 0, b.length); } @Override public void write(byte[] b, int off, int len) throws IOException { while (len > 0) { final int c = Math.min(len, decoderIn.remaining()); decoderIn.put(b, off, c); processInput(false); len -= c; off += c; } flush(); } @Override public void flush() throws IOException { flushOutput(); out.flush(); } @Override public void close() throws IOException { processInput(true); flush(); out.close(); }
Decode the contents of the input ByteBuffer into a CharBuffer.
Params:
  • endOfInput – indicates end of input
Throws:
/** * Decode the contents of the input ByteBuffer into a CharBuffer. * * @param endOfInput indicates end of input * @throws IOException if an I/O error occurs */
private void processInput(final boolean endOfInput) throws IOException { // Prepare decoderIn for reading decoderIn.flip(); CoderResult coderResult; while (true) { coderResult = decoder.decode(decoderIn, decoderOut, endOfInput); if (coderResult.isOverflow()) { flushOutput(); } else if (coderResult.isUnderflow()) { break; } else { // The decoder is configured to replace malformed input and unmappable characters, // so we should not get here. throw new IOException("Unexpected coder result"); } } // Discard the bytes that have been read decoderIn.compact(); }
Flush the output.
Throws:
  • IOException – if an I/O error occurs
/** * Flush the output. * * @throws IOException if an I/O error occurs */
private void flushOutput() throws IOException { if (decoderOut.position() > 0) { out.write(decoderOut.array(), 0, decoderOut.position()); decoderOut.rewind(); } } }