    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.Writer;
    020
    021/**
    022 * Proxy writer that prevents the underlying writer from being closed.
    023 * <p>
    024 * This class is typically used in cases where a writer needs to be passed to a
    025 * component that wants to explicitly close the writer even if other components
    026 * would still use the writer for output.
    027 * </p>
    028 *
    029 * @since 2.7
    030 */
    031public class CloseShieldWriter extends ProxyWriter {
    032
    033    /**
    034     * Constructs a proxy that shields the given writer from being closed.
    035     *
    036     * @param writer the writer to wrap
    037     * @return the created proxy
    038     * @since 2.9.0
    039     */
    040    public static CloseShieldWriter wrap(final Writer writer) {
    041        return new CloseShieldWriter(writer);
    042    }
    043
    044    /**
    045     * Constructs a proxy that shields the given writer from being closed.
    046     *
    047     * @param writer underlying writer
    048     * @deprecated Using this constructor prevents IDEs from warning if the
    049     *             underlying writer is never closed. Use {@link #wrap(Writer)}
    050     *             instead.
    051     */
    052    @Deprecated
    053    public CloseShieldWriter(final Writer writer) {
    054        super(writer);
    055    }
    056
    057    /**
    058     * Replaces the underlying writer with a {@link ClosedWriter} sentinel. The
    059     * original writer will remain open, but this proxy will appear closed.
    060     */
    061    @Override
    062    public void close() {
    063        out = ClosedWriter.INSTANCE;
    064    }
    065
    066}