检索清单对象，或者如果在给定的Jar文件中找不到清单，则创建一个空的清单对象

/*nowjava.com - 时  代  Java*/

//package com.nowjava;


import java.io.File;


import java.io.IOException;


import java.util.Enumeration;


import java.util.jar.JarEntry;

import java.util.jar.JarFile;


import java.util.jar.Manifest;


public class Main {

    public static final String META_INF = "META-INF";


    /**

     * Retrieves a Manifest object or creates an empty Manifest object 

     * if the Manifest is not found in the given Jar file

     * @param jarFile

     * @return

     * @throws IOException

     */

    public static Manifest getManifest(File jarFile) throws IOException {/** 时 代 J a v a 公 众 号 - N o w J a v  a . c o m 提 供 **/

        JarFile jar = new JarFile(jarFile);

        String manifestPath = META_INF + "/MANIFEST.MF";

        JarEntry jarEntry = jar.getJarEntry(manifestPath);

        if (jarEntry != null) {

            Enumeration<JarEntry> entries = jar.entries();

            while (entries.hasMoreElements()) {

                jarEntry = (JarEntry) entries.nextElement();

                if (manifestPath.equalsIgnoreCase(jarEntry.getName())) {

                    break;

                } else {

                    jarEntr