GWT RequestFactory與Objectify：ServerFailure錯誤時返回請求時觸發

Question

我想在Eclipse上自定義App Engine Connected Android項目。我使用Objectify代替JPA，並且一直遵循Turbocharge示例來設置我的基本框架（使用DAO層）。我正在從事網絡方面的工作，但我無法讓我的實體堅持在開發服務器上：我的請求在Receivers的onFailure（）方法上返回ServerFailure錯誤。但並沒有提供任何線索，爲什麼這是（所有變量都爲空）。

任何幫助將不勝感激！

這裏是我的入口點類：

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); 
     } 
    }); 

我也跟着在調試模式下的代碼通過堆到返回錯誤的點。這裏的堆棧

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  

在這裏，我有變量的快照響應和錯誤：

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

此錯誤表明服務器有一個錯誤，因此「服務器錯誤：空「 - 拋出異常，但沒有任何消息與它發送給客戶端相關聯。根據您的代碼，它可能位於服務器上的saveAndReturn方法中。嘗試通過那裏，或用try/catch圍繞方法的主體來獲取錯誤。如果發生錯誤時正在使用足夠的日誌記錄，則您的服務器日誌可能會更清楚地說明問題。