自定义ClassLoader加载加密的class文件

package com.yd.wmsc.util;

public class Test {
       public void say(){
            System.out.println("Say Hello");
        }
}

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;


public class FileUtils {

    public static void test(String path){
        File file = new File(path);
        try {
            FileInputStream fis = new FileInputStream(file);
            FileOutputStream fos = new FileOutputStream(path+"en");
            int b = 0;
            int b1 = 0;
            try {
                while((b = fis.read()) != -1){
                    //每一个byte异或一个数字2
                    fos.write(b ^ 2);
                }
                fos.close();
                fis.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;


public class DeClassLoader extends ClassLoader {

    private String mLibPath;

    public DeClassLoader(String path) {
        // TODO Auto-generated constructor stub
        mLibPath = path;
    }

    @Override
    protected Class<?> findClass(String name) throws ClassNotFoundException {
        // TODO Auto-generated method stub

        String fileName = getFileName(name);

        File file = new File(mLibPath,fileName);

        try {
            FileInputStream is = new FileInputStream(file);

            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            int len = 0;
            byte b = 0;
            try {
                while ((len = is.read()) != -1) {
                    //将数据异或一个数字2进行解密
                    b = (byte) (len ^ 2);
                    bos.write(b);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }

            byte[] data = bos.toByteArray();
            is.close();
            bos.close();

            return defineClass(name,data,0,data.length);

        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return super.findClass(name);
    }

    //获取要加载 的class文件名
    private String getFileName(String name) {
        // TODO Auto-generated method stub
        int index = name.lastIndexOf('.');
        if(index == -1){ 
            return name+".classen";
        }else{
            return name.substring(index+1)+".classen";
        }
    }

}

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

public class ClassLoaderTest {

    public static void main(String[] args) {
        FileUtils.test("D:\\Test.class");
        DeClassLoader diskLoader = new DeClassLoader("D:\\");
        try {
            //加载class文件
            Class c = diskLoader.loadClass("com.yd.wmsc.util.Test");

            if(c != null){
                try {
                    Object obj = c.newInstance();
                    Method method = c.getDeclaredMethod("say",null);
                    //通过反射调用Test类的say方法
                    method.invoke(obj, null);
                } catch (InstantiationException | IllegalAccessException 
                        | NoSuchMethodException
                        | SecurityException | 
                        IllegalArgumentException | 
                        InvocationTargetException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}