src/main/java/org/apache/commons/net/io/SocketOutputStream.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.commons.net.io;

import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;

/**
 * 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
 * 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
 * want to make sure it closes when the stream closes.
 *
 *
 * @see SocketInputStream
 */

public class SocketOutputStream extends FilterOutputStream {
    private final Socket socket;

    /**
     * Creates a SocketOutputStream instance wrapping an output stream and storing a reference to a socket that should be closed on closing the stream.
     *
     * @param socket The socket to close on closing the stream.
     * @param stream The input stream to wrap.
     */
    public SocketOutputStream(final Socket socket, final OutputStream stream) {
        super(stream);
        this.socket = socket;
    }

    /**
     * Closes the stream and immediately afterward closes the referenced socket.
     *
     * @throws IOException If there is an error in closing the stream or socket.
     */
    @Override
    public void close() throws IOException {
        super.close();
        socket.close();
    }

    /**
     * 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
     * because the FilterOutputStream implementation is very inefficient.
     *
     * @param buffer The byte array to write.
     * @param offset The offset into the array at which to start copying data.
     * @param length The number of bytes to write.
     * @throws IOException If an error occurs while writing to the underlying stream.
     */
    @Override
    public void write(final byte buffer[], final int offset, final int length) throws IOException {
        out.write(buffer, offset, length);
    }
}