Adding, editing, deleting grid rows using the Struts2 jQuery Grid plugin

I am trying to do CRUD operations using the struts jQuery grid using the struts2-jquery-grid-3.7.0 plugin , as shown in showcase , Grid (Editable / Multi Selector).

This is the form:

<s:form namespace="/admin_side" action="Test" validate="true" id="dataForm" name="dataForm">
    <s:url id="remoteurl" action="TestGrid" namespace="/admin_side"/>
    <s:url id="editurl" action="EditTest"/>
    <sjg:grid
        id="gridmultitable"
        caption="Example (Editable/Multiselect)"
        dataType="json"
        href="%{remoteurl}"
        pager="true"
        navigator="true"
        navigatorSearchOptions="{sopt:['eq','ne','lt','gt']}"
        navigatorEdit="true"
        navigatorView="true"
        navigatorAddOptions="{height:280, width:500, reloadAfterSubmit:true}"
        navigatorEditOptions="{height:280, width:500, reloadAfterSubmit:false}"                
        navigatorViewOptions="{height:280, width:500}"
        navigatorDelete="true"
        navigatorDeleteOptions="{height:280, width:500,reloadAfterSubmit:true}"
        gridModel="gridModel"
        rowList="5,10,15"
        rowNum="5"
        rownumbers="true"                
        editurl="%{editurl}"
        editinline="true"
        multiselect="true"
        onSelectRowTopics="rowselect">

        <sjg:gridColumn name="countryId" index="countryId" title="Id" formatter="integer" editable="false" dataType="Long" sortable="true" search="true" sorttype="integer" searchoptions="{sopt:['eq','ne','lt','gt']}"/>
        <sjg:gridColumn name="countryName" index="countryName" title="Country Name" editable="true" sortable="true" search="true" sorttype="text"/>
        <sjg:gridColumn name="countryCode" index="countryCode" title="Country Code" sortable="true" search="true" editable="true" sorttype="text"/>

    </sjg:grid>
</s:form>

The method is displayed in the corresponding action class, which is called when operations are performed, such as adding, deleting and editing a line.

@Namespace("/admin_side")
@ResultPath("/WEB-INF/content")
@ParentPackage(value = "json-package")
@InterceptorRefs(
    @InterceptorRef(value = "store", params = {"operationMode", "AUTOMATIC"}))
public final class TestAction extends ActionSupport implements Serializable, ModelDriven<Country>
{
    @Autowired
    private final transient CountryService countryService=null;
    private static final long serialVersionUID = 1L;

    private Country entity=new Country();
    private List<Country> gridModel=new ArrayList<Country>();

    private String oper; //Getter and setter.

    @Action(value = "EditTest",
    results = {
        @Result(name = ActionSupport.SUCCESS, location = "Test.jsp"),
        @Result(name = ActionSupport.INPUT, location = "Test.jsp")},
    interceptorRefs = {
        @InterceptorRef(value = "defaultStack", params = {"validation.validateAnnotatedMethodOnly", "true", "validation.excludeMethods", "load"})})
    public String edit() throws Exception {
        System.out.println(entity.getCountryId()+" : "+entity.getCountryName()+" : "+entity.getCountryCode()+" : "+oper);

        if(oper.equalsIgnoreCase("add")) {
             //Adding a row.   
        }
        else if(oper.equalsIgnoreCase("edit")) {
             //Editing/updating a row. 
        }
        else if(oper.equalsIgnoreCase("del")) {
             //Deleting a row.
        }
        return ActionSupport.SUCCESS;
    }

    @Override
    public Country getModel() {
        return entity;
    }

    @Action(value = "Test",
    results = {
        @Result(name = ActionSupport.SUCCESS, location = "Test.jsp"),
        @Result(name = ActionSupport.INPUT, location = "Test.jsp")},
    interceptorRefs = {
        @InterceptorRef(value = "defaultStack", params = {"validation.validateAnnotatedMethodOnly", "true", "validation.excludeMethods", "load"})})
    public String load() throws Exception {
        //This method is required to return an initial view on page load. Nothing to see here. Leave  it empty.
        return ActionSupport.SUCCESS;
    }
}

When deleting an identifier (in this case countryId) always null.

countryId null, editable="false" . true, , countryId , .

( )?

_ModelDriven.

EDIT:

id String , ,

private String id;

public String getId() {
    return id;
}

public void setId(String id) {
    this.id = id;
}

( ) .

, , .

, , . . ?