The problem is from the remote service URL, which will be will be empty if I don't use "ServiceDefTarget" to set the service entry point. If I uncommented the three lines below, it works fine.
In Explorer.java from GXT 2.2.5, I don't see any need to use ServiceDefTarget. Can you please explain what has happened? When should I use ServiceDefTarget? I must miss something importatnt.
=== Code sample from my customized Explorer.java ===
FRMServiceAsync service = (FRMServiceAsync) GWT.create(FRMService.class);
//ServiceDefTarget endpoint = (ServiceDefTarget) service;
//String moduleRelativeURL = "service";
=== Code sample from Explorer.java in GXT 2.2.5 ===
ExampleServiceAsync service = (ExampleServiceAsync) GWT.create