    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}