动态代理

接口

package cn.itheima.dynamic;


public interface TargetInterface {


void insert();

}

目标对象

package cn.itheima.dynamic;


public class Target implements TargetInterface {


@Override
public void insert() {
// TODO Auto-generated method stub
System.out.println("插入数据");
}

}

获取代理对象

package cn.itheima.dynamic;


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




public class DynamicProxy implements InvocationHandler {
public static void main(String[] args, int a) {
/*
* final Target target = new Target(); TagetInterface newProxyInstance =
* (TagetInterface)
* Proxy.newProxyInstance(Target.class.getClassLoader(),
* Target.class.getInterfaces(), new InvocationHandler() {
* 
* @Override public Object invoke(Object proxy, Method method, Object[]
* args) throws Throwable { // TODO Auto-generated method stub
* System.out.println("插入之前的逻辑"); method.invoke(target, args);
* System.out.println("插入之后的逻辑"); return null; } });
* newProxyInstance.insert(); }
*/


}
Target target = new Target();
public TargetInterface getProxy() {
TargetInterface instance = (TargetInterface) Proxy.newProxyInstance(Target.class.getClassLoader(),
Target.class.getInterfaces(), this);
return instance;
}


@Override
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
// TODO Auto-generated method stub
System.out.println("插入数据前");
method.invoke(target, args);
System.out.println("插入数据后");
return null;
}

}

测试

package cn.itheima.dynamic;


public class Demo {


public static void main(String[] args) {
DynamicProxy proxy = new DynamicProxy();
TargetInterface proxy2 = proxy.getProxy();
proxy2.insert();
}

}