[Struts 2] Problem setting back indexed properties from JSP to action class.

Question

Hi,

We are working with struts 2.0.14 and facing problem setting back indexed properties from JSP to action class.

Code looks similar to this.

  public class MyExample extends ActionSupport
        {

            private List<Person> persons;
            private List<String> names;

            public String execute()
            {
                //persons = myDAO.readPersons(names);
                return SUCCESS;
            }

            public String update()
            {
                for (Person p : persons)
                {
                    System.out.println(p.getName() + "---" + p.getAddress().getStreet());
                }
                return SUCCESS;
            }

            // Getters and setters     
        }

        class Person
        {
            private Address address;
            private String name;
             // Getters and setters    
        }

        class Address
        {
            private String street;
            private String number;   
             // Getters and setters    
        }

   And JSP:
       <%@ taglib prefix="s" uri="/struts-tags"%>
       <%@ page language="java" pageEncoding="ISO-8859-1"%>
       <!---- Other code ---->
       <s:ieterate value="persons" status="status">
        <tr>
          <s:textfield name="person['%{#status.index}'].name"/>
          <s:textfield name="person['%{#status.index}'].address.number"/>
           <s:textfield name="person['%{#status.index}'].street"/>
        </tr>

I could successfully display values onto the page, but when i submit the form the values are not getting populated. I checked firebug to see how the parameters are posted and they are like person['0'].name, person['0'].address.number etc., Please let me know where the mistake lies.

Answer 1

Did you try without the ' around the %{#status.index}?

Like this:

<s:textfield name="person[%{#status.index}].name"/>

Answer 2

In addition to removing the quotes around the index as Nate suggests, I noticed that your field is named persons but your parameters use person instead. Assuming that's a typo and it should be, for instance, persons[%{#status.index}].name, make sure:

1. Your action has a setPersons(List<Person> person) so that it can create a new list and set it.
2. Person and Address have no-arg constructors so that they can be automatically created on the fly.

If it's still not working, try adding the @Element (com.opensymphony.xwork2.util.Element) to persons to give it a hint about what type of object to fill it with:

@Element(value=Person)
List<Person> persons;

One other thing that might be happening is one of the superclasses of your action may implement ParameterNameAware which filters out parameters by name. A quick way to check is to override acceptableParameterName in your action and see if it makes it work:

@Override
public boolean acceptableParameterName(String name) {
    return true;
}

See the API docs for ParametersInterceptor for more details: http://struts.apache.org/2.0.14/struts2-core/apidocs/com/opensymphony/xwork2/interceptor/ParametersInterceptor.html

Answer 3

Person and Address have no-arg constructors so that they can be automatically created on the fly.