src/main/java/org/apache/maven/it/util/ResourceExtractor.java

package org.apache.maven.it.util;

/*
 * 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.
 */

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.Enumeration;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
import org.apache.maven.shared.utils.io.FileUtils;
import org.apache.maven.shared.utils.io.IOUtil;


/**
 *  @todo this can be replaced with plexus-archiver
 */
public class ResourceExtractor
{

    public static File simpleExtractResources( Class<?> cl, String resourcePath )
        throws IOException
    {
        String tempDirPath = System.getProperty( "maven.test.tmpdir", System.getProperty( "java.io.tmpdir" ) );
        File tempDir = new File( tempDirPath );

        File testDir = new File( tempDir, resourcePath );

        FileUtils.deleteDirectory( testDir );

        testDir = ResourceExtractor.extractResourcePath( cl, resourcePath, tempDir, false );
        return testDir;
    }

    public static File extractResourcePath( String resourcePath, File dest )
        throws IOException
    {
        return extractResourcePath( ResourceExtractor.class, resourcePath, dest );
    }

    public static File extractResourcePath( Class<?> cl, String resourcePath, File dest )
        throws IOException
    {
        return extractResourcePath( cl, resourcePath, dest, false );
    }

    public static File extractResourcePath( Class<?> cl, String resourcePath, File tempDir, boolean alwaysExtract )
        throws IOException
    {
        File dest = new File( tempDir, resourcePath );
        return extractResourceToDestination( cl, resourcePath, dest, alwaysExtract );
    }

    public static File extractResourceToDestination( Class<?> cl, String resourcePath, File destination,
                                                     boolean alwaysExtract )
        throws IOException
    {
        URL url = cl.getResource( resourcePath );
        if ( url == null )
        {
            throw new IllegalArgumentException( "Resource not found: " + resourcePath );
        }
        if ( "jar".equalsIgnoreCase( url.getProtocol() ) )
        {
            File jarFile = getJarFileFromUrl( url );
            extractResourcePathFromJar( cl, jarFile, resourcePath, destination );
        }
        else
        {
            try
            {
                File resourceFile = new File( new URI( url.toExternalForm() ) );
                if ( !alwaysExtract )
                {
                    return resourceFile;
                }
                if ( resourceFile.isDirectory() )
                {
                    FileUtils.copyDirectoryStructure( resourceFile, destination );
                }
                else
                {
                    FileUtils.copyFile( resourceFile, destination );
                }
            }
            catch ( URISyntaxException e )
            {
                throw new RuntimeException( "Couldn't convert URL to File:" + url, e );
            }
        }
        return destination;
    }

    private static void extractResourcePathFromJar( Class<?> cl, File jarFile, String resourcePath, File dest )
        throws IOException
    {
        ZipFile z = new ZipFile( jarFile, ZipFile.OPEN_READ );
        String zipStyleResourcePath = resourcePath.substring( 1 ) + "/";
        ZipEntry ze = z.getEntry( zipStyleResourcePath );
        if ( ze != null )
        {
            // DGF If it's a directory, then we need to look at all the entries
            for ( Enumeration<? extends ZipEntry> entries = z.entries(); entries.hasMoreElements(); )
            {
                ze = entries.nextElement();
                if ( ze.getName().startsWith( zipStyleResourcePath ) )
                {
                    String relativePath = ze.getName().substring( zipStyleResourcePath.length() );
                    File destFile = new File( dest, relativePath );
                    if ( ze.isDirectory() )
                    {
                        destFile.mkdirs();
                    }
                    else
                    {
                        FileOutputStream fos = new FileOutputStream( destFile );
                        try
                        {
                            IOUtil.copy( z.getInputStream( ze ), fos );
                        }
                        finally
                        {
                            IOUtil.close( fos );
                            z.close();
                        }
                    }
                }
            }
        }
        else
        {
            FileOutputStream fos = new FileOutputStream( dest );
            try
            {
                IOUtil.copy( cl.getResourceAsStream( resourcePath ), fos );
            }
            finally
            {
                IOUtil.close( fos );
                z.close();
            }
        }
    }

    private static File getJarFileFromUrl( URL url )
    {
        if ( !"jar".equalsIgnoreCase( url.getProtocol() ) )
        {
            throw new IllegalArgumentException( "This is not a Jar URL:" + url.toString() );
        }
        String resourceFilePath = url.getFile();
        int index = resourceFilePath.indexOf( "!" );
        if ( index == -1 )
        {
            throw new RuntimeException( "Bug! " + url.toExternalForm() + " does not have a '!'" );
        }
        String jarFileURI = resourceFilePath.substring( 0, index );
        try
        {
            File jarFile = new File( new URI( jarFileURI ) );
            return jarFile;
        }
        catch ( URISyntaxException e )
        {
            throw new RuntimeException( "Bug! URI failed to parse: " + jarFileURI, e );
        }

    }
}