java如何通过代码实现本身的jar

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.jar.JarEntry;
import java.util.jar.JarOutputStream;

public class JarCreator {
    public static void main(String[] args) {
        String jarName = "MyApp.jar"; // 指定要创建的JAR文件名
        String mainClass = "com.example.Main"; // 指定主类的全限定名

        try (JarOutputStream jarOut = new JarOutputStream(new FileOutputStream(jarName))) {
            File classFile = new File("path/to/YourMainClass.class"); // 指定主类编译后的class文件路径
            addToJar(classFile, jarOut, mainClass); // 将主类添加到JAR文件中

            // 添加其他依赖的类文件或资源文件
            // addToJar(new File("path/to/OtherClass.class"), jarOut, null);
            // addToJar(new File("path/to/resource.txt"), jarOut, null);

            System.out.println("JAR created successfully.");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private static void addToJar(File file, JarOutputStream jarOut, String mainClass) throws IOException {
        String entryName = file.getName();
        JarEntry entry = new JarEntry(entryName);

        if (mainClass != null && entryName.equals(mainClass.replace(".", "/") + ".class")) {
            entryName = "META-INF/MANIFEST.MF";
            entry = new JarEntry(entryName);
            jarOut.putNextEntry(entry);
            jarOut.write(("Manifest-Version: 1.0\nMain-Class: " + mainClass).getBytes());
            jarOut.closeEntry();
        }

        entry.setMethod(JarEntry.DEFLATED);
        jarOut.putNextEntry(entry);

        // 从文件读取内容并写入JAR
        // 可以使用 FileInputStream、BufferedInputStream 等读取文件内容，然后使用 jarOut.write 写入JAR

        jarOut.closeEntry();
    }
}