    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 *      http://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 */
    017package org.apache.commons.io.output;
    018
    019import java.io.IOException;
    020import java.io.OutputStream;
    021import java.util.function.Supplier;
    022
    023/**
    024 * Broken output stream. This stream always throws an {@link IOException} from
    025 * all {@link OutputStream} methods.
    026 * <p>
    027 * This class is mostly useful for testing error handling in code that uses an
    028 * output stream.
    029 * </p>
    030 *
    031 * @since 2.0
    032 */
    033public class BrokenOutputStream extends OutputStream {
    034
    035    /**
    036     * A singleton instance.
    037     *
    038     * @since 2.12.0
    039     */
    040    public static final BrokenOutputStream INSTANCE = new BrokenOutputStream();
    041
    042    /**
    043     * A supplier for the exception that is thrown by all methods of this class.
    044     */
    045    private final Supplier<IOException> exceptionSupplier;
    046
    047    /**
    048     * Creates a new stream that always throws an {@link IOException}.
    049     */
    050    public BrokenOutputStream() {
    051        this(() -> new IOException("Broken output stream"));
    052    }
    053
    054    /**
    055     * Creates a new stream that always throws the given exception.
    056     *
    057     * @param exception the exception to be thrown.
    058     */
    059    public BrokenOutputStream(final IOException exception) {
    060        this(() -> exception);
    061    }
    062
    063    /**
    064     * Creates a new stream that always throws an {@link IOException}.
    065     *
    066     * @param exceptionSupplier a supplier for the exception to be thrown.
    067     * @since 2.12.0
    068     */
    069    public BrokenOutputStream(final Supplier<IOException> exceptionSupplier) {
    070        this.exceptionSupplier = exceptionSupplier;
    071    }
    072
    073    /**
    074     * Throws the configured exception.
    075     *
    076     * @throws IOException always thrown
    077     */
    078    @Override
    079    public void close() throws IOException {
    080        throw exceptionSupplier.get();
    081    }
    082
    083    /**
    084     * Throws the configured exception.
    085     *
    086     * @throws IOException always thrown
    087     */
    088    @Override
    089    public void flush() throws IOException {
    090        throw exceptionSupplier.get();
    091    }
    092
    093    /**
    094     * Throws the configured exception.
    095     *
    096     * @param b ignored
    097     * @throws IOException always thrown
    098     */
    099    @Override
    100    public void write(final int b) throws IOException {
    101        throw exceptionSupplier.get();
    102    }
    103
    104}