如何加載從資源調用的jar文件的主類

Question

我在Java中寫了幾行以在運行時從資源中運行jar文件

首先我把罐子裝滿

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

創建字節數組

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

讀取字節數組中文件的內容

 fileInputStream.read(rawBytes); 

我如何從此fileInputStream加載主類

---

這是我從類調用方法的測試，我如何用jar文件制作此示例？

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

嘗試加載該類並調用main方法，或者僅嘗試從cmd運行它。

試試這個代碼：

    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]);