代理模式是一种注重过程的一种模式,在我们做某一具体事情之前或之后做一些辅助性的工作; 好处是将辅助工作从主要工作中抽离出来,但是又能协同工作, 我们只关心主要业务,对于不关心的事情交给代理来做,实现代理需要两个对象:被代理者,执行者
JDK中提供的动态代理(只能代理接口):
代码语言：javascript复制public interface IBuy {
void pay();
}
public class Buy implements IBuy{
@Override
public void pay() {
System.out.println("订单支付完成!");
}
public class PayProxy implements InvocationHandler {
private Object obj;
public PayProxy(Object target) {
this.obj = target;
}
public Object newInstance() {
Class<? extends Object> cls = obj.getClass();
return Proxy.newProxyInstance(cls.getClassLoader(), cls.getInterfaces(), this);
}
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
Object res = method.invoke(obj, args);
System.out.println("----------");
sendMsg();
return res;
}
private void sendMsg(){
System.out.println("买家已付款,请尽快发货!");
}
}
--------------
IBuy buy = (IBuy)new PayProxy(new Buy()).newInstance();
buy.pay();
console:
订单支付完成!
----------
买家已付款,请尽快发货!CGLIB方式(代理具体类):
代码语言：javascript复制public class Buy{
public void pay() {
System.out.println("订单支付完成!");
}
}
public class CglibPayProxy implements MethodInterceptor {
private static final CglibPayProxy PROXY = new CglibPayProxy();
private CglibPayProxy() {
}
public static CglibPayProxy getInstance() {
return PROXY;
}
@SuppressWarnings("unchecked")
public <T> T newProxy(Class<T> clazz) {
Enhancer enhancer = new Enhancer();
enhancer.setSuperclass(clazz);
enhancer.setCallback(this);
return (T) enhancer.create();
}
@Override
public Object intercept(Object arg0, Method arg1, Object[] arg2, MethodProxy arg3)
throws Throwable {
Object res = arg3.invokeSuper(arg0, arg2);
System.out.println("------------");
sendMsg();
return res;
}
private void sendMsg() {
System.out.println("买家已付款,请尽快发货!");
}
Buy buy = CglibPayProxy.getInstance().newProxy(Buy.class);
buy.pay();
