java动态代理 InvocationHandler

版权声明：转载请注明来源 https://blog.csdn.net/genghaihua/article/details/89385852

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.Arrays;


interface Hello {
    String sayHello(String str);
}

// 实现
class HelloImp implements Hello {
    @Override
    public String sayHello(String str) {
        return "HelloImp: " + str;
    }
}

class LogInvocationHandler implements InvocationHandler {
    private Object target;

    public Object getProxyInstance(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 {
        if ("sayHello".equals(method.getName())) {
            System.out.println("You said: " + Arrays.toString(args));
        }
        return method.invoke(target, args);
    }
}

public class Test1 {
    public static void main(String[] args) {
        LogInvocationHandler logInvocationHandler = new LogInvocationHandler();
        Hello hello = (Hello) logInvocationHandler.getProxyInstance(new HelloImp());
        System.out.println(hello.sayHello("I love you!"));
    }
}