    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.io.output;
    019
    020import java.io.OutputStream;
    021
    022/**
    023 * Proxy stream that prevents the underlying output stream from being closed.
    024 * <p>
    025 * This class is typically used in cases where an output stream needs to be 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 underlying output stream is never closed. Use {@link #wrap(OutputStream)} instead.
    049     */
    050    @Deprecated
    051    public CloseShieldOutputStream(final OutputStream outputStream) {
    052        super(outputStream);
    053    }
    054
    055    /**
    056     * Replaces the underlying output stream with a {@link ClosedOutputStream} sentinel. The original output stream will remain open, but this proxy will appear
    057     * closed.
    058     */
    059    @Override
    060    public void close() {
    061        out = ClosedOutputStream.INSTANCE;
    062    }
    063}