Question

我在java中写了一些行来运行来自资源的jar文件

首先我得到了jar填充

// create FileInputStream object
InputStream fileInputStream = TestCL.class.getResourceAsStream("test.jar");

创建字节数组

byte rawBytes[] = new byte[fileInputStream.available()];

以字节数组

读取文件的内容

fileInputStream.read(rawBytes);

我如何从这个fileInputStream加载主类

这是我从类调用方法的测试，我怎么能用jar文件制作这个例子？

package testcl;

import java.io.InputStream;

public class TestCL extends ClassLoader {

    public static void main(String args[]) throws Exception {
        TestCL javaClassLoader = new TestCL();
        javaClassLoader.load();

    }

    public void load() throws Exception {

        // create FileInputStream object
        InputStream fileInputStream = TestCL.class.getResourceAsStream("ClassLoaderInput.class");
        byte rawBytes[] = new byte[fileInputStream.available()];
        fileInputStream.read(rawBytes);

        // Load the target class
        Class<?> regeneratedClass = this.defineClass(rawBytes, 0, rawBytes.length);

        // Getting a method from the loaded class and invoke it
        regeneratedClass.getMethod("printString", null).invoke(regeneratedClass.newInstance(), null);
    }

}

Answer 1

尝试加载类并调用main方法或尝试从cmd运行它。

试试这段代码：

    Class<?>[] cArgs = new Class[1]; 
    cArgs[0] = java.lang.String.class;
    URL url = new URL("// enter the .jar path");
    URL[] urls = new URL[] { url };
    ClassLoader cl = new URLClassLoader(urls);
    InputStream fileInputStream = cl.getResourceAsStream("test.jar");
    Method mainMethod = cl.loadClass("//enter class name").getMethod("main", cArgs[0]);

如何加载从资源调用的jar文件的mainclass

1 个答案: