RPCManager RPCRequest how to capture the response in gwt - gwt

Question

hi i have requirement to capture the data for validations. i am able to fetch the data using RPCRequest and RPCManager by using setActionUrl to the controller class.from there creating the service class and dao classes .i am able to fetch the data into controller class.but i am unable get the data back into my grid.i want the data to be fetched into a variable.i am not using asynchronus service.i used async method in grid i am able to fetch into onSuccess() method.but without using how i can fetch.the data into grid.
with regards
subodh

Answer 1

Here example in our ServiceImpl class to retrive datas from DB
public final String getDatas(final HashMap<String, String> param) {
List<ShippingBean> result = null;
JSONObject obj = new JSONObject();
try {
// retrieve data from DB
data = dao.selectAll();
}
catch (BusinessException e) {
throw new InvocationException("BusinessException occurs ...", e);
}
obj = JSONObject.fromObject(result);
return obj.toString();
}
We use net.sf.json to serialize as DOM and return this to presenter call as AsyncCallBack method. And then , retrieve data as like that..
AsyncCallback<String> callback = new AsyncCallback<String>() {
public void onFailure(final Throwable caught) {
Window.alert("Error!");
}
public void onSuccess(final String result) {
HTML html = new HTML(result.replace(" ", "-"));
JSONValue value = JSONParser.parseLenient(html.getText());
JSONWrapper json = new JSONWrapper(value);
System.out.println(json.get(0).get("variableName").stringValue());
}
};

Answer 2

I have done something similar within a project with retrieve data and posting it to GWT from database. My database setup was Microsoft SQL 2012 and Hibernate framework to retrieve it. However I created a custom try/catch block and if/else bocks for validation on client side.
I used this tutorial from Hibernate to GWT to set up the transactions between the web application and the database for both saving and retrieving. Their source code provides the web page modules for setting up the displaying which I mimicked to fit to my needs since I was not storing "records" or "users".
GWT does have a validation setup but I spent a 10 hours trying to figure out the client side validation and gave up for something much simpler such as try/catch on the data being submitted since I had no concern for the format of the numbers.
Google "GWT Validation" and you should have some documentation about it but their isn't that much to choose from since everything seems to be a copy of Google's documentation.
Link - Hibernate to GWT
Hope this helps or points you in the right direction towards your answer.