jqGrid with Struts 2

Question

I need to display a grid, with having Struts2 on a back end. I have a class Tuple representing the data, in which I created a method toJson() that is to return JsonObject (using Google GSON framework)

At the end of the day I get empty grid, seen on the picture.

Here are the details:

public class Tuple implements Serializable{
//other methods here..
 public JsonObject toJson() {
    //create JSON referemce
    jSonRef = new JsonObject();
    jSonRef.add("ProposalId", new JsonPrimitive( m_lngProposalId) );
    jSonRef.add("ProposalLabel",  new JsonPrimitive(m_strProposalLabel) );
    jSonRef.add("AnalysisStatus",  new JsonPrimitive(m_strAnalysisStatus) );


    jSonRef.add("lockedBy", m_strLockedBy!=null? new  
            JsonPrimitive(m_strLockedBy): new JsonPrimitive("") );

         return jSonRef ;
}
//       other stuff here ...
 }//end of the class

jSonRef is a member variable of the class.

struts.xml is like this:

 <action name="JsonGetter" class="com.bvn.ecost.framework.actions.JSonGetterAction">
<result name="success" type="json"/>
 </action>

The action class is:

package com.bvn.ecost.framework.actions;

import org.apache.log4j.LogManager;
import org.apache.log4j.Logger;
import com.google.gson.JsonArray;
import com.opensymphony.xwork2.Action;


 public class JSonGetterAction extends SuperAction{ //extends SuperAction
private static final Logger log = LogManager.getLogger(ReportDealAction.class);
private String results = null ;

public String execute() {
      JsonArray propsArray = loadProposalsJson() //method from superclass, returning 
                                                 //JsonArray
  results = propsArray.toString() ;

  return Action.SUCCESS ;
}

public String getResults() {
    return results;
}

public void setResults(String results) {
    this.results = results;
}   
 }

JSP page:

<code>
<%@ page trimDirectiveWhitespaces="true" %>
<%@ page language="java" %>
<%@ page import="com.bvn.ecost.*" %>
<%@ page import="java.sql.SQLException" %>
<%@ page import="java.sql.Connection" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<%
try {

%>`
<!DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"    
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<HTML xmlns="http://www.w3.org/1999/xhtml" >
<HEAD>
<link rel="stylesheet" type="text/css" href="css/mainStyles.css" />
<link type="text/css" href="css/redmond/jquery-ui-1.8.23.custom.css" media="screen" 
rel="stylesheet" />
<link type="text/css" href="css/ui.jqgrid.css" media="screen" rel="stylesheet" />
<link type="text/css" href="css/jquery.loadmask.css" media="screen" rel="stylesheet" />
<link type="text/css" href="css/ui.app.css" media="screen" rel="stylesheet" />
<script type="text/javascript" src="js/jquery-1.8.3.min.js"></script>
<script type="text/javascript" src="js/jquery-ui-1.8.23.custom.min.js"></script>
<script type="text/javascript" src="js/grid.locale-en.js"></script>
<script type="text/javascript" src="js/jquery.jqGrid.min.js"></script>
<script type="text/javascript" src="js/jquery.validate.js"></script>
<script type="text/javascript" src="js/jquery.loadmask.js"></script>
<script type="text/javascript" src="js/app-helper.js"></script>
<script type="text/javascript">
    $(document).ready(function (){
        $.getJSON('JsonGetter.action', function(data) {
            alert("Inside .getJson()") ;
            console.log("data->results:  "+data.results) ;
            var this_grid;
            this_grid = $this_app.define_grid("#grid-results", {
                caption: 'Proposal Grid',
                pager: '#pager-results',
                data: $.extend(true, [], data.results),
                datatype: "local",
colModel: [
  { name: 'ProposalId', index: 'ProposalId', width: 120, label: 'Proposal Id' },
      { name: 'ProposalLabel', index: 'ProposalLabel', width: 120, label: 'Label' },
  { name: 'AnalysisStatus', index: 'AnalysisStatus', width: 120, label: 'Status' },
  { name: 'lockedBy', index: 'lockedBy', width: 440, label: 'Locked by' }
],
inline_editing: false,
pager_options: {
  del: false                        
}); 
        }
) <!-- end of getJSon() -->
    });    
</script>
</HEAD>
<BODY>

<table align="center" width="100%"> <!-- Wrapper table -->
<tr>
<td>
<table align="center" width="100%"> <!-- Header image table -->
    <jsp:include page="commonHead.jsp" flush="true" />
    <tr>    
    <td colspan="10" align="center" style="color:#00509e">
    <b><s:property value="statusString"/></b>
    </td>
</tr>                   
</table>
</td>
</tr>
<tr>
<td>
        <table align="center" width="60%">
            <tr align="center">
                <TD align="left">
                    <div id="div-results">
                        <table id="grid-results">

                        </table>
                        <div id="pager-results">
                        <div/>
                    </div>
                    <span id="results-status-message"></span>
                </TD>
            </tr>
        </table>    
    </td>
</tr>
   </table>
   </BODY>
   </HTML>
 <%
}
catch (Exception e) {
    Helper.handleException(e, request, response, out);
}
 %>

I am getting complete page, but empty grid:

empty grid

The line "console.log("data->results: "+data.results) ;" shows the Json in the browser JavaScript console, like this:

data->results:  [{"ProposalId":35145,"ProposalLabel":"US Laminating Corp 1","AnalysisStatus":"WIP","lockedBy":"cost-analyzer-admin"}]

I understand that it could be somehow incorrect, but do not know how. Also, I tried to have a results variable in the action as JsonObject (and changing the way it obtains a value to this)

results.add("result", propsArray) ;

And then changing the JSP line with specifying data: to be like:

data: $.extend(true, [], data.results.result),

But I get some kind of UnsupportedOperationException in the browser.

score 1 · Accepted Answer · edited May 23 '17 at 11:58

1

You are getting JSON object via the json plugin that serializes all action properties, that might be not necessary to get the grid model. Why not to create a grid model object and return it serialized to JSON by specifying the root parameter of the result. Anyway misunderstanding a difference between the stringified version of JSON and JSON object don't let you apply a JSON object to the grid. With the results field you have gotten a stringified JSON that needs to parse to a JSON object like $.parseJSON(data); then apply it to the grid model.

Not necessary, If you are using Struts 2 why not to use struts2-jquery-plugin and make grids more easier like described here.

This question also could be helpful to resolve this issue.

edited May 23 '17 at 11:58

Community

1
1

answered Jul 20 '13 at 12:13

Roman C

49,761
33
66
176

Thank you, Roman. By far, this is the best answer or suggested solution I found all around so far. I chosen Struts for this, because I got exposed to it in my J2EE exposure, but seems like it's hard to find consolidated knowledge available. Would you advise a good resource on it? I picked up "Struts2 in action" book, which is quite all right but enough when the need comes to quickly solve few isues. – Dima R. Jul 23 '13 at 14:16
1

@DimaR. If you can quickly solve then good for you, every solution comes as a result of hard working, any resource is helpful, this site is great, books are good for the learning, internet is big. So, good luck, and don't forget to mark this answer as accepted if you liked this answer. – Roman C Jul 23 '13 at 14:49

score 0 · Answer 2 · answered Jul 25 '13 at 20:45

I was struggling with this for quite a while, thinking that the problems I am having is due to not understanding Jquery/gqgird/javascript, etc. While that may still be the case, I solved the issue of displaying the data, simply by not using google gson library, and serializing a custom java bean object that maps to my data. Maybe someone can find this useful, and won't have to spend as much time:

The errors I was getting was due to fact that Struts json plugin uses reflection to find properties on an object to be serialized. As a result, since JsonObject extends JsonElement from google library, struts sees the bunch of getter methods which it thinks are to be serialized. All the methods

getAsBigDecimal()
getAsString(..)
etc..

were interpreted as properties

asBigDecimal
asString
asBoolean
etc..

and were expected to be found in the Json object. Of course they weren't found in my custom data, originally added to JsonObject using

addProperty()

method, so deeply burried in struts-json-plugin there were JsonException caught, related to InvocationTargetException .

Thanks, to whoever tried to help.

jqGrid with Struts 2

2 Answers2