java動態(tài)代理實(shí)現(xiàn)demo
2021-10-20 10:26:50

/**
 * @author JingZhe  @time 2021/10/20 9:45
 */
public interface Person {
    /** 測試方法 */
    void doSomething();
}

/**
 * @author JingZhe  @time 2021/10/20 9:48
 */
public class JingZhe implements Person {

    @Override
    public void doSomething() {
        System.out.println("jingZhe doing Something");
    }
}

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

/**
 * @author JingZhe  @time 2021/10/20 9:44
 */
public class JDKDynamicProxy implements InvocationHandler {

    /** 聲明被代理的對象 */
    private Person person;

    /** 構(gòu)造函數(shù) */
    public JDKDynamicProxy(Person person) {
        this.person = person;
    }

    /** 獲取代理對象 */
    public Object getProxy() {
        Object proxyInstance = Proxy.newProxyInstance(person.getClass().getClassLoader(), person.getClass().getInterfaces(), this);
        return proxyInstance;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("對原方法進(jìn)行了前置增強(qiáng)");
        // 原方法執(zhí)行
        Object invoke = method.invoke(person, args);
        System.out.println("對原方法進(jìn)行了后置增強(qiáng)");
        return invoke;
    }
}

/**
 * @author JingZhe  @time 2021/10/20 9:46
 */
public class proxyTest {
    public static void main(String[] args) {

        System.out.println("不使用代理類，調(diào)用doSomething");
        Person person = new JingZhe();
        person.doSomething();

        System.out.println("--------------------------");

        System.out.println("使用代理類，調(diào)用doSomething");
        Person proxy = (Person) new JDKDynamicProxy(new JingZhe()).getProxy();
        proxy.doSomething();

    }
}

不使用代理類，調(diào)用doSomething
jingZhe doing Something
--------------------------
使用代理類，調(diào)用doSomething
對原方法進(jìn)行了前置增強(qiáng)
jingZhe doing Something
對原方法進(jìn)行了后置增強(qiáng)