001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      https://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.net.io;
019
020import java.io.FilterOutputStream;
021import java.io.IOException;
022import java.io.OutputStream;
023import java.net.Socket;
024
025/**
026 * This class wraps an output stream, storing a reference to its originating socket. When the stream is closed, it will also close the socket immediately
027 * afterward. This class is useful for situations where you are dealing with a stream originating from a socket, but do not have a reference to the socket, and
028 * want to make sure it closes when the stream closes.
029 *
030 * @see SocketInputStream
031 */
032public class SocketOutputStream extends FilterOutputStream {
033    private final Socket socket;
034
035    /**
036     * Creates a SocketOutputStream instance wrapping an output stream and storing a reference to a socket that should be closed on closing the stream.
037     *
038     * @param socket The socket to close on closing the stream.
039     * @param stream The input stream to wrap.
040     */
041    public SocketOutputStream(final Socket socket, final OutputStream stream) {
042        super(stream);
043        this.socket = socket;
044    }
045
046    /**
047     * Closes the stream and immediately afterward closes the referenced socket.
048     *
049     * @throws IOException If there is an error in closing the stream or socket.
050     */
051    @Override
052    public void close() throws IOException {
053        super.close();
054        socket.close();
055    }
056
057    /**
058     * Writes a number of bytes from a byte array to the stream starting from a given offset. This method bypasses the equivalent method in FilterOutputStream
059     * because the FilterOutputStream implementation is very inefficient.
060     *
061     * @param buffer The byte array to write.
062     * @param offset The offset into the array at which to start copying data.
063     * @param length The number of bytes to write.
064     * @throws IOException If an error occurs while writing to the underlying stream.
065     */
066    @Override
067    public void write(final byte buffer[], final int offset, final int length) throws IOException {
068        out.write(buffer, offset, length);
069    }
070}