java的jdk动态代理和cglib动态代理

最新推荐文章于 2024-08-05 07:30:00 发布

原创最新推荐文章于 2024-08-05 07:30:00 发布 · 122 阅读

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本文介绍了Java中两种动态代理实现方式：JDK动态代理和CGLIB动态代理。前者要求代理对象与目标对象实现相同的接口，并通过实现InvocationHandler接口完成方法拦截；后者则通过继承目标类实现代理，要求拦截器实现MethodInterceptor接口。

jdk动态代理

/**
 * @ClassName:
 * @Description: Jdk的动态代理：代理对象跟目标对象要实现相同接口，拦截器必须实现InvocationHandler接口
 * @yanchan [280822963@qq.com]
 * @date 2018/4/11 0011 14:11
 */
public class IInvocationHandler implements InvocationHandler {

    private Object obj;

    public IInvocationHandler(Object obj) {
        this.obj = obj;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        System.out.println("before");
        method.invoke(obj, args);
        System.out.println("after");
        return null;
    }

    public static void main(String[] args) {
        Man man = new Man();
        IInvocationHandler var = new IInvocationHandler(man);
        Person proxyInstance = (Person) Proxy.newProxyInstance(man.getClass().getClassLoader(), man.getClass().getInterfaces(), var);
        proxyInstance.eat();

    }
}

2.cglib动态代理

/**
 * @ClassName:
 * @Description: cglib 动态代理: 代理对象是目标对象的子类 ,拦截器必须实现MethodInterceptor接口
 * @yanchan [280822963@qq.com]
 * @date 2018/4/11 0011 12:09
 */
public class IMethodInterceptor implements MethodInterceptor {

    private Object targetObj;

    public IMethodInterceptor(Object targetObj) {
        this.targetObj = targetObj;
    }

    @Override
    public Object intercept(Object o, Method method, Object[] objects, MethodProxy methodProxy) throws Throwable {
        System.out.println("before");
        method.invoke(targetObj, objects);
        System.out.println("after");
        return null;
    }

    public static void main(String[] args) {
        IMethodInterceptor interceptor = new IMethodInterceptor(new Person());
        Enhancer enhancer = new Enhancer();
        enhancer.setCallback(interceptor);
        enhancer.setSuperclass(Person.class);
        Person proxyObj = (Person) enhancer.create();
        proxyObj.eat();
    }
}