cglib初接触

  <dependencies>
  <dependency>
    <groupId>cglib</groupId>
    <artifactId>cglib-nodep</artifactId>
    <version>3.1</version>
</dependency>
  
  <dependency>
    <groupId>org.ow2.asm</groupId>
    <artifactId>asm</artifactId>
    <version>5.0.3</version>
</dependency>

package CglibTest.CglibTest;

public class HelloWorld {
    
    public void sayHello(){
        System.out.println("Hello world");
    }

}

package CglibTest.CglibTest;

import java.lang.reflect.Method;

import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

/**
 * Hello world!
 *
 */
public class App 
{
    public static void main( String[] args )
    {
        
        
        Enhancer enhancer = new Enhancer();
        enhancer.setSuperclass(HelloWorld.class);
        enhancer.setCallback(new MyMethodInterceptor());
        HelloWorld hw=(HelloWorld) enhancer.create();
        hw.sayHello();
        
        
    }
}

/*
 * 
 */
class MyMethodInterceptor implements MethodInterceptor{

    public Object intercept(Object arg0, Method arg1, Object[] arg2,
            MethodProxy arg3) throws Throwable {
        // TODO Auto-generated method stub
        System.out.println("before "+arg1.getName()+" "+arg2.length);//arg1是要调用的方法,arg2不知道是什么...
        Object o = arg3.invokeSuper(arg0,arg2);//看接口的说明arg0应该是指this
        System.out.println("after");
        return o;
    }
    
}