src/test/java/org/apache/commons/compress/DetectCompressorTestCase.java

/*
 * 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.commons.compress;

import static org.apache.commons.compress.AbstractTestCase.getFile;

import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import junit.framework.TestCase;

import org.apache.commons.compress.compressors.CompressorException;
import org.apache.commons.compress.compressors.CompressorInputStream;
import org.apache.commons.compress.compressors.CompressorStreamFactory;
import org.apache.commons.compress.compressors.bzip2.BZip2CompressorInputStream;
import org.apache.commons.compress.compressors.gzip.GzipCompressorInputStream;
import org.apache.commons.compress.compressors.pack200.Pack200CompressorInputStream;
import org.apache.commons.compress.compressors.xz.XZCompressorInputStream;

public final class DetectCompressorTestCase extends TestCase {

    public DetectCompressorTestCase(String name) {
        super(name);
    }

    final CompressorStreamFactory factory = new CompressorStreamFactory();

    public void testDetection() throws Exception {
        CompressorInputStream bzip2 = getStreamFor("bla.txt.bz2"); 
        assertNotNull(bzip2);
        assertTrue(bzip2 instanceof BZip2CompressorInputStream);

        CompressorInputStream gzip = getStreamFor("bla.tgz");
        assertNotNull(gzip);
        assertTrue(gzip instanceof GzipCompressorInputStream);
        
        CompressorInputStream pack200 = getStreamFor("bla.pack");
        assertNotNull(pack200);
        assertTrue(pack200 instanceof Pack200CompressorInputStream);

        CompressorInputStream xz = getStreamFor("bla.tar.xz");
        assertNotNull(xz);
        assertTrue(xz instanceof XZCompressorInputStream);

        try {
            factory.createCompressorInputStream(new ByteArrayInputStream(new byte[0]));
            fail("No exception thrown for an empty input stream");
        } catch (CompressorException e) {
            // expected
        }
    }

    private CompressorInputStream getStreamFor(String resource)
            throws CompressorException, IOException {
        return factory.createCompressorInputStream(
                   new BufferedInputStream(new FileInputStream(
                       getFile(resource))));
    }

}