Ant example source code file (BZip2Resource.java)

This example Ant source code file (BZip2Resource.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Ant tags/keywords

bzip2, bzip2resource, bzip2resource, cbzip2inputstream, cbzip2outputstream, compressedresource, inputstream, invalid, io, ioexception, ioexception, magic, magic, string, z

The BZip2Resource.java source code

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */
package org.apache.tools.ant.types.resources;

import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;

import org.apache.tools.bzip2.CBZip2InputStream;
import org.apache.tools.bzip2.CBZip2OutputStream;

/**
 * A Bzip2 compressed resource.
 *
 * <p>Wraps around another resource, delegates all quries to that
 * other resource but uncompresses/compresses streams on the fly.</p>
 *
 * @since Ant 1.7
 */
public class BZip2Resource extends CompressedResource {
    private static final char[] MAGIC = new char[] {'B', 'Z'};

    /** A no-arg constructor */
    public BZip2Resource() {
    }

    /**
     * Constructor with another resource to wrap.
     * @param other the resource to wrap.
     */
    public BZip2Resource(org.apache.tools.ant.types.ResourceCollection other) {
        super(other);
    }

    /**
     * Decompress on the fly using {@link CBZip2InputStream}.
     * @param in the stream to wrap.
     * @return the wrapped stream.
     * @throws IOException if there is a problem.
     */
    protected InputStream wrapStream(InputStream in) throws IOException {
        for (int i = 0; i < MAGIC.length; i++) {
            if (in.read() != MAGIC[i]) {
                throw new IOException("Invalid bz2 stream.");
            }
        }
        return new CBZip2InputStream(in);
    }

    /**
     * Compress on the fly using {@link CBZip2OutputStream}.
     * @param out the stream to wrap.
     * @return the wrapped stream.
     * @throws IOException if there is a problem.
     */
    protected OutputStream wrapStream(OutputStream out) throws IOException {
        for (int i = 0; i < MAGIC.length; i++) {
            out.write(MAGIC[i]);
        }
        return new CBZip2OutputStream(out);
    }

    /**
     * Get the name of the compression method.
     * @return the string "Bzip2".
     */
    protected String getCompressionName() {
        return "Bzip2";
    }
}