How to make the struts2 JSON plugin work on List of custom object?

[Nakataa Kokuyo]

Good day,

I try doing a sample to understand how the Struts2 JSON plugin work and below is my code snippet:

My problem is that, mystring, myStringList are able to display out, but jSONShowList doesn't , it showing two empty pair of {}. I guess the records is being pull out but couldn't display out the result, any clue what did i miss out ?

Code :

     String mystring="just anew test";
    List<String> myStringList = Arrays.asList("this","is","myStringList");
    List<JsonDataObject> jSONShowList;

    public List<String> getMyStringList() {
        return myStringList;
    }

    public void setMyStringList(List<String> myStringList) {
        this.myStringList = myStringList;
    }

    public List<JsonDataObject> getjSONShowList() {
        return jSONShowList;
    }

    public void setjSONShowList(List<JsonDataObject> jSONShowList) {
        this.jSONShowList = jSONShowList;
    }

    public String getMystring() {
        return mystring;
    }

    public void setMystring(String mystring) {
        this.mystring = mystring;
    }

    public String execute(){
        //setMystring("this msg from testAction!!!");
        List<JsonDataObject> jSONListTemp = new ArrayList<JsonDataObject>();
        jSONListTemp.add(new JsonDataObject("a","b", 1));
        jSONListTemp.add(new JsonDataObject("c","d", 2));

        setjSONShowList(jSONListTemp);
        return Action.SUCCESS;
    }

JsonDataObject code :

public class JsonDataObject {    
    private String node1, node2;
    private int number;

    public JsonDataObject (String node1, String node2, int number) {
        this.node1 = node1;
        this.node2 = node2;
        this.number = number;
    }

    public String toString(){
        return "node1:"+node1+", node2:"+node2+", number:"+number;
    }
}