interactivespaces.resource.analysis.OsgiResourceAnalyzer.java Source code

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Here is the source code for interactivespaces.resource.analysis.OsgiResourceAnalyzer.java

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/*
 * Copyright (C) 2013 Google Inc.
 *
 * Licensed 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 interactivespaces.resource.analysis;

import interactivespaces.resource.NamedVersionedResourceCollection;
import interactivespaces.resource.NamedVersionedResourceWithData;
import interactivespaces.resource.Version;

import org.apache.commons.logging.Log;

import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.util.jar.Attributes;
import java.util.jar.JarFile;
import java.util.jar.Manifest;

/**
 * A resource analyzer for OSGi resources.
 *
 * @author Keith M. Hughes
 */
public class OsgiResourceAnalyzer implements ResourceAnalyzer {

    /**
     * OSGi manifest header for getting the OSGi bundle symbolic name.
     */
    private static final String OSGI_HEADER_SYMBOLIC_NAME = "Bundle-SymbolicName";

    /**
     * OSGi manifest header for getting the OSGi bundle version.
     */
    private static final String OSGI_HEADER_VERSION = "Bundle-Version";

    /**
     * Logger for the analyzer.
     */
    private final Log log;

    /**
     * Construct an analyzer.
     *
     * @param log
     *          the log to use
     */
    public OsgiResourceAnalyzer(Log log) {
        this.log = log;
    }

    @Override
    public NamedVersionedResourceCollection<NamedVersionedResourceWithData<String>> getResourceCollection(
            File baseDir) {
        NamedVersionedResourceCollection<NamedVersionedResourceWithData<String>> resources = NamedVersionedResourceCollection
                .newNamedVersionedResourceCollection();

        File[] files = baseDir.listFiles(new FileFilter() {
            @Override
            public boolean accept(File pathname) {
                return pathname.getName().endsWith(".jar");
            }
        });

        if (files != null) {
            for (File file : files) {
                JarFile jarFile = null;
                try {
                    jarFile = new JarFile(file);
                    Manifest manifest = jarFile.getManifest();
                    Attributes attributes = manifest.getMainAttributes();
                    String name = attributes.getValue(OSGI_HEADER_SYMBOLIC_NAME);
                    String version = attributes.getValue(OSGI_HEADER_VERSION);
                    if (name != null && version != null) {
                        NamedVersionedResourceWithData<String> resource = new NamedVersionedResourceWithData<String>(
                                name, Version.parseVersion(version), file.getAbsolutePath());

                        resources.addResource(resource.getName(), resource.getVersion(), resource);
                    } else {
                        log.warn(String.format(
                                "Resource %s is not a proper OSGi bundle (missing symbolic name and/or version) and is being ignored.",
                                file.getAbsolutePath()));
                    }
                } catch (IOException e) {
                    log.error(String.format("Could not open resource file jar manifest for %s",
                            file.getAbsolutePath()), e);
                } finally {
                    // For some reason Closeables does not work with JarFile despite it
                    // claiming it is Closeable in the Javadoc.
                    if (jarFile != null) {
                        try {
                            jarFile.close();
                        } catch (IOException e) {
                            // Don't care.
                        }
                    }
                }
            }
        }

        return resources;
    }
}