jdk代理
解释:程序在运行过程中，根据被代理的接口来动态生成代理类的class文件，并且加载运行。
JDK提供了java.lang.reflect.Proxy类来实现动态代理的，可通过它的newProxyInstance来获得代理实现类。
1:自定义接口
package javabase.allinterface;
public interface SaySimple {
void sayHelloForSomeone(String name);
}2:接口实现类
package javabase.allimpl;
import javabase.allinterface.SaySimple;
public class SaySimpleImpl01 implements SaySimple{
@Override
public void sayHelloForSomeone(String name) {
System.out.println("Hello!"+name);
}
}
3：自定义实现InvocationHandler接口的类
package javabase;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
public class ImplInvocationHandler implements InvocationHandler {
private Object targetObj;
public ImplInvocationHandler(Object obj) {
this.targetObj = obj;
}
/**
* @return
* GY
* 2017年11月6日
*/
public Object getProxy(){
return java.lang.reflect.Proxy.newProxyInstance(targetObj.getClass().getClassLoader(),
targetObj.getClass().getInterfaces(),
new ImplInvocationHandler(targetObj));
}
/*
*
*
*/
@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
System.out.println("Before invocation");
Object retVal = method.invoke(targetObj, args);
System.out.println("After invocation");
return retVal;
}
}
4：测试，用代理对象执行被代理接口实现类的方法
package javabase;
import java.lang.reflect.Proxy;
import javabase.allimpl.SaySimpleImpl01;
import javabase.allinterface.SaySimple;
public class TestOfInvocationHandler {
public static void main(String[] args) {
SaySimple s = new SaySimpleImpl01();
ImplInvocationHandler handle = new ImplInvocationHandler(s);
SaySimple proxy = (SaySimple)Proxy.newProxyInstance(//TestOfInvocationHandler.class.getClassLoader(),
handle.getClass().getClassLoader(),
//new Class[]{SaySimple.class},
s.getClass().getInterfaces(),
handle);
proxy.sayHelloForSomeone("GY");
SaySimple proxy2 = (SaySimple)handle.getProxy();
proxy2.sayHelloForSomeone("WX");
}
}
