특정 객체에 대해 Struts2 JSON 플러그인 직렬화를 사용자 정의하는 방법은 무엇입니까?

<result type="json">
    <param name="root">
        objectToBeSerialized
    </param>
</result>

public class MyRow implements Serializable {
    private String col1;
    private String col2;

    // Getters and setters omitted for brevity
}

public class PartAction implements Serializable {
    private List<MyRow> rows;

    public List<MyRow> getRows() { return rows; }

    public String finder() {
        rows = new ArrayList<>();
        // Loop through search results and populate rows
        return Action.SUCCESS;
    }
}

<package name="default" namespace="/ajax" extends="json-default">
    <action name="finder" class="action.Part" method="finder">
        <result type="json">
            <param name="root">rows</param>
        </result>
    </action>
</package>

var handledata = function(data) {
    $.each(data, function(index) {
        alert(data[index].col1);
        alert(data[index].col2);
    });
}