chenweicai

package proxy;
/**
?*
?* @author chen
?*
?*/
public interface Subject {
?abstract public void request();
?abstract public void request2();
}


package proxy;

/**
?*
?* @author chen
?*
?*/
public class RealSubject implements Subject {
?
?public RealSubject(){
?}

?public void request() {
??// TODO Auto-generated method stub
??System.out.println("From real subject.request().");
?}
?
?public void request2() {
??// TODO Auto-generated method stub
??System.out.println("From real subject.request2()");
?}
}

package proxy;

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

/**
?*
?* @author chenweicai
?*
?*/
public class DynamicSubject implements InvocationHandler {
?
?private Object sub;
?
?public DynamicSubject(){
?}
?
?public DynamicSubject(Object obj){
??this.sub = obj;
?}

?public Object invoke(Object proxy, Method method, Object[] args)
???throws Throwable {
??// TODO Auto-generated method stub
???? System.out.println("before calling " + method);
???? method.invoke(sub,args);
???? System.out.println("after calling " + method);
??return null;
?}

}


package proxy;

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

/**
?*
?* @author chen
?*
?*/
public class Client {
?static public void main(String[] args)
??????? throws Throwable{
??? RealSubject rs = new RealSubject();? //在這里指定被代理類
??? InvocationHandler ds = new DynamicSubject(rs);? //初始化代理類
??? Class cls = rs.getClass();
??
??? //以下是分解步驟
??? /*Class c = Proxy.getProxyClass(cls.getClassLoader(),cls.getInterfaces()) ;
??? Constructor ct=c.getConstructor(new Class[]{InvocationHandler.class});
??? Subject subject =(Subject) ct.newInstance(new Object[]{ds});*/
??
??? //以下是一次性生成
??? Subject subject = (Subject) Proxy.newProxyInstance(cls.getClassLoader(),
??? cls.getInterfaces(),ds );

??? subject.request2();
?? }
}