GWT RequestFactory with Objectify: ServerFailure error returns when firing request - google-app-engine

Question

I'm trying to customize the App Engine Connected Android project on Eclipse. I'm using Objectify in place of JPA and have been following the Turbocharge example to setup my basic framework (using a DAO layer).
I'm currently working on the web side of things, but I'm having trouble getting my entities to persist on the development server: my requests return a ServerFailure error on Receivers' onFailure() method. But doesn't really provide any clues as to why that is (all variables are null).
Any help would be greatly appreciated!
Here's my EntryPoint class:
public class Manager implements EntryPoint {
private static final Logger log = Logger.getLogger(Manager.class.getName());
private final EventBus eventBus = new SimpleEventBus();
private ManagerRequestFactory rf = GWT.create(ManagerRequestFactory.class);
#Override
public void onModuleLoad() {
GWT.setUncaughtExceptionHandler(new UncaughtExceptionHandler() {
#Override
public void onUncaughtException(Throwable e) {
log.finest("uncaught exception: ");
e.printStackTrace();
}
});
rf.initialize(eventBus);
log.setLevel(Level.FINE);
PersonRequest personRequest = rf.personRequest();
// Populate the database with sample data
PersonProxy person = personRequest.create(PersonProxy.class);
person.setFirstName("John1");
person.setLastName("Doe");
person.setEmail("jd#gmail.com");
person.setMainPhone("215-555-1212");
personRequest.saveAndReturn(person).fire(new Receiver<PersonProxy>(){
#Override
public void onSuccess(PersonProxy response) {
log.info("got response: " + response.getFirstName());
}
#Override
public void onFailure(ServerFailure error) {
log.info("Server Failure type: " + error.getExceptionType());
log.info("Failure message: " + error.getMessage());
log.info("Stack Trace: " + error.getStackTraceString());
log.info(error.isFatal() ? "error is fatal" : "error is not fatal");
super.onFailure(error);
}
});
I followed the code in debug mode through the stacks to the point where it returns the error. Here's the Stack
Daemon Thread [Code server for manager from Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.7 (KHTML, like Gecko) Chrome/16.0.912.75 Safari/535.7 on http://127.0.0.1:8888/manager/hosted.html?manager # d6:JVCMo.q:W,$wW] (Suspended (exception UmbrellaException))
AbstractRequestContext$StandardPayloadDialect.processPayload(Receiver<Void>, String) line: 387
AbstractRequestContext$5.onTransportSuccess(String) line: 1108
DefaultRequestTransport$1.onResponseReceived(Request, Response) line: 136
Request.fireOnResponseReceived(RequestCallback) line: 287
RequestBuilder$1.onReadyStateChange(XMLHttpRequest) line: 395
NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not available [native method]
NativeMethodAccessorImpl.invoke(Object, Object[]) line: not available
DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: not available
Method.invoke(Object, Object...) line: not available
MethodAdaptor.invoke(Object, Object...) line: 103
MethodDispatch.invoke(JsValue, JsValue[], JsValue) line: 71
OophmSessionHandler.invoke(BrowserChannelServer, BrowserChannel$Value, int, BrowserChannel$Value[]) line: 172
BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer$SessionHandlerServer) line: 337
BrowserChannelServer.invokeJavascript(CompilingClassLoader, JsValueOOPHM, String, JsValueOOPHM[], JsValueOOPHM) line: 218
ModuleSpaceOOPHM.doInvoke(String, Object, Class<?>[], Object[]) line: 136
ModuleSpaceOOPHM(ModuleSpace).invokeNative(String, Object, Class<?>[], Object[]) line: 561
ModuleSpaceOOPHM(ModuleSpace).invokeNativeObject(String, Object, Class<?>[], Object[]) line: 269
JavaScriptHost.invokeNativeObject(String, Object, Class<?>[], Object[]) line: 91
Impl.apply(Object, Object, Object) line: not available
Impl.entry0(Object, Object, Object) line: 213
NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not available [native method]
NativeMethodAccessorImpl.invoke(Object, Object[]) line: not available
DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: not available
Method.invoke(Object, Object...) line: not available
MethodAdaptor.invoke(Object, Object...) line: 103
MethodDispatch.invoke(JsValue, JsValue[], JsValue) line: 71
OophmSessionHandler.invoke(BrowserChannelServer, BrowserChannel$Value, int, BrowserChannel$Value[]) line: 172
BrowserChannelServer.reactToMessages(BrowserChannelServer$SessionHandlerServer) line: 292
BrowserChannelServer.processConnection() line: 546
BrowserChannelServer.run() line: 363
Thread.run() line: not available
And here I have a snapshot of the Variables for response and error:
response ResponseMessageAutoBean$1 (id=566)
this$0 ResponseMessageAutoBean (id=581)
data JsonSplittable (id=583)
array null
bool null
isNull false
number null
obj JSONObject (id=597)
reified HashMap<K,V> (id=598)
string null
factory MessageFactoryImpl (id=584)
creatorMap JavaScriptObject$ (id=608)
enumToStringMap HashMap<K,V> (id=609)
stringsToEnumsMap HashMap<K,V> (id=610)
frozen false
shim ResponseMessageAutoBean$1 (id=566)
this$0 ResponseMessageAutoBean (id=581)
data JsonSplittable (id=583)
factory MessageFactoryImpl (id=584)
frozen false
shim ResponseMessageAutoBean$1 (id=566)
tags null
usingSimplePeer true
wrapped ResponseMessageAutoBean$2 (id=587)
tags null
usingSimplePeer true
wrapped ResponseMessageAutoBean$2 (id=587)
causes HashSet<E> (id=570)
[0] RuntimeException (id=576)
cause RuntimeException (id=576)
detailMessage "Server Error: null" (id=579)
stackTrace null

Answer 1

This error indicates that the server had an error, hence "Server Error: null" - an exception was thrown, but no message was associated with it to send to the client. Based on your code, it is probably in the saveAndReturn method on the server. Try stepping through there, or surrounding the body of the method with a try/catch to get the error. Your server log may shed more light on the issue, if enough logging is being used when errors occur.