简单模拟struts中的Interceptor的调用过程遇到的问题

不明白struts中Interceptor的调用过程(Interceptors的遍历过程)，自己写了个小程序测试。得不到想要的结果 求大神指点啊~~ 代码如下：

public class Interceptor {
Invocation test;
String name;
public Interceptor(String name){
this.name=name;
}

public String intercept(Invocation test) {
            this.test=test;
            System.out.println("--name--1--"+name);
            test.invoke();
            System.out.println("--name--2--"+name);
            eturn super.toString();
}

}

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

public class Invocation {

public static void main(String[] args) {
        Invocation t = new Invocation();
        t.invoke();
}

    public void invoke(){
            List<Interceptor> list = new ArrayList<Interceptor>();
            list.add(new Interceptor("aaaaa"));
            list.add(new Interceptor("bbbbb"));
            list.add(new Interceptor("ccccc"));
            list.add(new Interceptor("ddddd"));
            list.add(new Interceptor("eeeee"));
            list.add(new Interceptor("fffff"));
            list.add(new Interceptor("ggggg"));
            list.add(new Interceptor("hhhhh"));
            Iterator<Interceptor>  iss =    list.iterator();
            if(iss.hasNext()){
                   Interceptor ms = iss.next(); 
                   ms.intercept(this);
           }

}