package Week_01;
import java.io.IOException;import java.lang.reflect.InvocationTargetException;import java.lang.reflect.Method;import java.nio.file.Files;import java.nio.file.Path;import java.nio.file.Paths;
/** * 自定义一个 Classloader，加载一个 Hello.xlass 文件，执行 hello 方法， * 此文件内容是一个 Hello.class 文件所有字节（x=255-x）处理后的文件。文件群里提供。 */public class HelloClassLoader extends ClassLoader {    public static void main(String[] args) {            try {                Class<?> helloClass = new HelloClassLoader().findClass("Hello");                Method helloMethod = helloClass.getMethod("hello");                helloMethod.invoke(helloClass.newInstance());            } catch (ClassNotFoundException e) {                e.printStackTrace();            } catch (NoSuchMethodException e) {                e.printStackTrace();            } catch (IllegalAccessException e) {                e.printStackTrace();            } catch (InstantiationException e) {                e.printStackTrace();            } catch (InvocationTargetException e) {                e.printStackTrace();            }    }
    @Override    protected Class<?> findClass(String name) throws ClassNotFoundException {
        Path path = Paths.get("/Users/zhanghongang/Study/GeekBang/JavaCourse/JAVA-Homework/Week_01/Week_01/Hello.xlass");        byte[] helloBase64 = new byte[0];        try {            helloBase64 = Files.readAllBytes(path);        } catch (IOException e) {            e.printStackTrace();        }
        for (int i = 0; i < helloBase64.length; i++) {            helloBase64[i] = (byte) (255 - helloBase64[i]);        }
        return defineClass(name, helloBase64, 0, helloBase64.length);    }}