设计模式-JDK动态代理

JDK动态代理

JDK动态代理需要提供接口才能使用

• 1、定义接口

public interface HelloWorld {
    public void sayHello();
}

• 2、接口实现类

public class HelloWorldImpl implements HelloWorld {
    @Override
    public void sayHello() {
        System.out.println("hello world");
    }
}

• 3、代理对象的绑定和代理逻辑实现

public class JdkProxyExample implements InvocationHandler {

    private Object target=null;

    public Object bind(Object target){
        this.target=target;
        return Proxy.newProxyInstance(target.getClass().getClassLoader(),target.getClass().getInterfaces(),this);
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("进入代理逻辑方法");
        System.out.println("在调度真实对象之前的服务");
        Object obj=method.invoke(target,args);
        System.out.println("在调用真实对象之后的服务");
        return obj;
    }
}

• 4、测试

public class Main {
    public static void main(String[] args) {
        JdkProxyExample jdkProxyExample=new JdkProxyExample();
        HelloWorld proxy=(HelloWorld)jdkProxyExample.bind(new HelloWorldImpl());
        proxy.sayHello();
    }
}