    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.OutputStream;
    020
    021/**
    022 * Proxy stream that prevents the underlying output stream from being closed.
    023 * <p>
    024 * This class is typically used in cases where an output stream needs to be
    025 * passed to a component that wants to explicitly close the stream even if other
    026 * components would still use the stream for output.
    027 * </p>
    028 *
    029 * @since 1.4
    030 */
    031public class CloseShieldOutputStream extends ProxyOutputStream {
    032
    033    /**
    034     * Constructs a proxy that shields the given output stream from being closed.
    035     *
    036     * @param outputStream the output stream to wrap
    037     * @return the created proxy
    038     * @since 2.9.0
    039     */
    040    public static CloseShieldOutputStream wrap(final OutputStream outputStream) {
    041        return new CloseShieldOutputStream(outputStream);
    042    }
    043
    044    /**
    045     * Constructs a proxy that shields the given output stream from being closed.
    046     *
    047     * @param outputStream underlying output stream
    048     * @deprecated Using this constructor prevents IDEs from warning if the
    049     *             underlying output stream is never closed. Use
    050     *             {@link #wrap(OutputStream)} instead.
    051     */
    052    @Deprecated
    053    public CloseShieldOutputStream(final OutputStream outputStream) {
    054        super(outputStream);
    055    }
    056
    057    /**
    058     * Replaces the underlying output stream with a {@link ClosedOutputStream}
    059     * sentinel. The original output stream will remain open, but this proxy will
    060     * appear closed.
    061     */
    062    @Override
    063    public void close() {
    064        out = ClosedOutputStream.INSTANCE;
    065    }
    066
    067}