/*
 * 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.io.output;

import java.io.IOException;
import java.io.OutputStream;

/**
 * Closed output stream. This stream throws an exception on all attempts to
 * write something to the stream.
 * <p>
 * Typically uses of this class include testing for corner cases in methods
 * that accept an output stream and acting as a sentinel value instead of
 * a {@code null} output stream.
 *
 * @since 1.4
 */
public class ClosedOutputStream extends OutputStream {

    /**
     * A singleton.
     */
    public static final ClosedOutputStream CLOSED_OUTPUT_STREAM = new ClosedOutputStream();

    /**
     * Throws an {@link IOException} to indicate that the stream is closed.
     *
     * @param b ignored
     * @throws IOException always thrown
     */
    @Override
    public void write(final int b) throws IOException {
        throw new IOException("write(" + b + ") failed: stream is closed");
    }

    /**
     * Throws an {@link IOException} to indicate that the stream is closed.
     *
     * @throws IOException always thrown
     */
    @Override
    public void flush() throws IOException {
        throw new IOException("flush() failed: stream is closed");
    }
}
