/**
 *  Copyright 2005-2015 Red Hat, Inc.
 *
 *  Red Hat 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 io.fabric8.common.util;

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

/**
 */
public class Manifests {

    /**
     * Returns the entry from the manifest for the given name
     */
    public static String getManifestEntry(File file, String attributeName) throws IOException {
        Manifest manifest = getManifest(file);
        if (manifest != null) {
            return manifest.getMainAttributes().getValue(attributeName);
        }
        return null;
    }

    /**
     * Returns the entry from the manifest for the given name
     */
    public static Manifest getManifest(File file) throws IOException {
        JarFile jar = new JarFile(file);
        try {
            // only handle non OSGi jar
            return jar.getManifest();
        } finally {
            jar.close();
        }
    }

}
