动态代理

分为jdk自带代理
实现接口 InvocationHandler  ，用反射调用方法
获取代理类：Proxy.newProxyInstance(cls.getClassLoader(),cls.getInterfaces(), new TestProxy(obj));

实例：
public interface ReadFile {
    public void read();
}

public class Boss implements ReadFile {
    @Override
    public void read() {
        System.out.println("I'm reading files.");
    }
}

public class Secretary implements InvocationHandler {
    private Object object;
    public Secretary(Object object) {
        this.object = object;
    }
    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("I'm secretary.");
        Object result = method.invoke(object, args);
        return result;
    }
}

public class Main {
    public static void main(String[] args) {
        ReadFile boss = new Boss();
        InvocationHandler handler = new Secretary(boss);
        ReadFile secretary = (ReadFile) Proxy.newProxyInstance(
                boss.getClass().getClassLoader(),
                boss.getClass().getInterfaces(),
                handler);
        secretary.read();
    }
}



CGLIB具有简单易用，它的运行速度要远远快于JDK的Proxy动态代理：
public class CglibProxy implements MethodInterceptor {
    @Override
    public Object intercept(Object o, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
        System.out.println("++++++before " + methodProxy.getSuperName() + "++++++");
        System.out.println(method.getName());
        Object o1 = methodProxy.invokeSuper(o, args);
        System.out.println("++++++before " + methodProxy.getSuperName() + "++++++");
        return o1;
    }
}
public class Main2 {
    public static void main(String[] args) {
        CglibProxy cglibProxy = new CglibProxy();
 
        Enhancer enhancer = new Enhancer();
        enhancer.setSuperclass(UserServiceImpl.class);
        enhancer.setCallback(cglibProxy);
 
        UserService o = (UserService)enhancer.create();
        o.getName(1);
        o.getAge(1);
    }
}