JarManager.java：JAR包信息查看和内容列表工具，便于分析JAR结构

import java.io.*;
import java.util.jar.*;
import java.util.Enumeration;

public class JarManager {
    public static void main(String[] args) {
        if (args.length < 1) {
            System.out.println("用法: java JarManager <JAR路径> [操作]");
            System.out.println("操作: list(列出内容), info(查看信息)");
            return;
        }
        
        String jarPath = args[0];
        String operation = args.length > 1 ? args[1] : "info";
        
        try {
            switch (operation) {
                case "list":
                    listJarContents(jarPath);
                    break;
                case "info":
                default:
                    showJarInfo(jarPath);
                    break;
            }
        } catch (Exception e) {
            System.err.println("操作失败: " + e.getMessage());
            e.printStackTrace();
        }
    }
    
    public static void showJarInfo(String jarPath) throws IOException {
        try (JarFile jarFile = new JarFile(jarPath)) {
            System.out.println("JAR文件信息: " + jarPath);
            System.out.println("文件大小: " + jarFile.size() + " 字节");
            
            Manifest manifest = jarFile.getManifest();
            if (manifest != null) {
                System.out.println("\n清单信息:");
                manifest.write(System.out);
            } else {
                System.out.println("\n无清单信息");
            }
        }
    }
    
    public static void listJarContents(String jarPath) throws IOException {
        try (JarFile jarFile = new JarFile(jarPath)) {
            System.out.println("JAR包内容列表 (" + jarPath + "):");
            Enumeration<JarEntry> entries = jarFile.entries();
            while (entries.hasMoreElements()) {
                JarEntry entry = entries.nextElement();
                System.out.println((entry.isDirectory() ? "D " : "F ") + entry.getName());
            }
        }
    }
}