001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.commons.compress.compressors;
020
021import java.io.FilterOutputStream;
022import java.io.OutputStream;
023
024/**
025 * Abstracts all classes that compress an output stream.
026 *
027 * @param <T> The underlying OutputStream type.
028 */
029public abstract class CompressorOutputStream<T extends OutputStream> extends FilterOutputStream {
030
031    /**
032     * Constructs a new instance without a backing OutputStream.
033     * <p>
034     * You must initialize {@code this.out} after construction.
035     * </p>
036     */
037    public CompressorOutputStream() {
038        super(null);
039    }
040
041    /**
042     * Creates an output stream filter built on top of the specified underlying output stream.
043     *
044     * @param out the underlying output stream to be assigned to the field {@code this.out} for later use, or {@code null} if this instance is to be created
045     *            without an underlying stream.
046     * @since 1.27.0
047     */
048    public CompressorOutputStream(final T out) {
049        super(out);
050    }
051
052    /**
053     * Gets the underlying output stream.
054     *
055     * @return the underlying output stream.
056     * @since 1.27.0
057     */
058    @SuppressWarnings("unchecked")
059    protected T out() {
060        return (T) out;
061    }
062}