[appengine-java] self referral one-to-many relationship with null root
I have a class which has a collection of itself as its children. It is mapped as : @Persistent private Group parent; @Persistent(mappedBy= "parent") private List children; The problem is I cannot insert the root object. The call to makePersistent comes back successfully, but the entity is not in the database. I guess this object with this mapping can not have null parents. Is there anyway I can make the parent nullable? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~--~~~~--~~--~--~---
[appengine-java] Re: self referral one-to-many relationship with null root
Can someone please answer it. I appreciate it. On Sep 14, 5:09 pm, Arash wrote: > I have a class which has a collection of itself as its children. It is > mapped as : > > @Persistent > private Group parent; > @Persistent(mappedBy= "parent") > private List children; > > The problem is I cannot insert the root object. The call to > makePersistent comes back successfully, but the entity is not in the > database. I guess this object with this mapping can not have null > parents. Is there anyway I can make the parent nullable? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~--~~~~--~~--~--~---
[appengine-java] How to make parent optional
I have a one-to-many relationship, mapped as: @PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) @Extension(vendorName="datanucleus", key="gae.encoded-pk", value="true") private String key; @Persistent private String name; @Persistent(nullValue= NullValue.NONE) private Group parent; And in many side: @Persistent(mappedBy= "parent") private List children; I want to make the group property optional, but GAE refuses to save any student entity which does not have group assigned to them. Do you have any idea how I can fix it? --~--~-~--~~~---~--~~ You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-java@googlegroups.com To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en -~--~~~~--~~--~--~---
[appengine-java] Re: 500 Server Error
Did you get any solution for this? On May 4, 3:34 am, Alexander Gavrilov wrote: > Hello, GWT Gurus! > > I am frequently getting 500 Server error, when application is running > on appspot, not locally. It is usually happens after application has > been just deployed or after a couple of hours I haven't touched it, > while it was running in browser. > > In logs I get this exception: > > # > com.google.inject.internal.FinalizableReferenceQueue$SystemLoader > loadFinalizer: Not allowed to access system class loader. > > # > 05-03 10:58PM 53.370 > com.google.inject.internal.FinalizableReferenceQueue : Failed to > start reference finalizer thread. Reference cleanup will only occur > when new references are created. > java.lang.reflect.InvocationTargetException > at com.google.appengine.runtime.Request.process- > a34bf020cfbce66a(Request.java) > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) > at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) > at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) > at java.lang.reflect.Method.invoke(Method.java:43) > at > com.google.inject.internal.FinalizableReferenceQueue.(FinalizableRefe > renceQueue.java: > 124) > at com.google.inject.internal.MapMaker > $QueueHolder.(MapMaker.java:787) > at com.google.inject.internal.MapMaker$WeakEntry.(MapMaker.java: > 946) > at com.google.inject.internal.MapMaker$Strength > $1.newEntry(MapMaker.java:312) > at com.google.inject.internal.MapMaker > $StrategyImpl.newEntry(MapMaker.java:498) > at com.google.inject.internal.MapMaker > $StrategyImpl.newEntry(MapMaker.java:419) > at com.google.inject.internal.CustomConcurrentHashMap > $ComputingImpl.get(CustomConcurrentHashMap.java:2029) > at > com.google.inject.internal.BytecodeGen.getClassLoader(BytecodeGen.java: > 149) > at > com.google.inject.internal.BytecodeGen.getClassLoader(BytecodeGen.java: > 132) > at > com.google.inject.internal.BytecodeGen.newFastClass(BytecodeGen.java: > 162) > at com.google.inject.internal.DefaultConstructionProxyFactory > $1.(DefaultConstructionProxyFactory.java:52) > at > com.google.inject.internal.DefaultConstructionProxyFactory.create(DefaultCo > nstructionProxyFactory.java: > 50) > at com.google.inject.internal.ProxyFactory.create(ProxyFactory.java: > 147) > at > com.google.inject.internal.ConstructorInjectorStore.createConstructor(Const > ructorInjectorStore.java: > 75) > at com.google.inject.internal.ConstructorInjectorStore.access > $000(ConstructorInjectorStore.java:27) > at com.google.inject.internal.ConstructorInjectorStore > $1.create(ConstructorInjectorStore.java:35) > at com.google.inject.internal.ConstructorInjectorStore > $1.create(ConstructorInjectorStore.java:31) > at com.google.inject.internal.FailableCache > $1.apply(FailableCache.java:35) > at com.google.inject.internal.MapMaker > $StrategyImpl.compute(MapMaker.java:549) > at com.google.inject.internal.MapMaker > $StrategyImpl.compute(MapMaker.java:419) > at com.google.inject.internal.CustomConcurrentHashMap > $ComputingImpl.get(CustomConcurrentHashMap.java:2041) > at com.google.inject.internal.FailableCache.get(FailableCache.java: > 46) > at > com.google.inject.internal.ConstructorInjectorStore.get(ConstructorInjector > Store.java: > 48) > at > com.google.inject.internal.ConstructorBindingImpl.initialize(ConstructorBin > dingImpl.java: > 113) > at > com.google.inject.internal.InjectorImpl.initializeBinding(InjectorImpl.java : > 367) > at > com.google.inject.internal.InjectorImpl.createJustInTimeBinding(InjectorImp > l.java: > 619) > at > com.google.inject.internal.InjectorImpl.createJustInTimeBindingRecursive(In > jectorImpl.java: > 551) > at > com.google.inject.internal.InjectorImpl.getJustInTimeBinding(InjectorImpl.j > ava: > 162) > at > com.google.inject.internal.InjectorImpl.getBindingOrThrow(InjectorImpl.java : > 122) > at > com.google.inject.internal.InjectorImpl.getInternalFactory(InjectorImpl.jav a: > 625) > at com.google.inject.internal.FactoryProxy.notify(FactoryProxy.java: > 43) > at > com.google.inject.internal.BindingProcessor.runCreationListeners(BindingPro > cessor.java: > 235) > at > com.google.inject.internal.InjectorBuilder.initializeStatically(InjectorBui > lder.java: > 132) > at > com.google.inject.internal.InjectorBuilder.build(InjectorBuilder.java: > 106) > at com.google.inject.Guice.createInjector(Guice.java:93) > at com.google.inject.Guice.createInjector(Guice.java:70) > at com.google.inject.Guice.createInjector(Guice.java:60) > at > com.myapp.DispatcherServletContextListener.getInjector(DispatcherServletCon > textListener.java: > 16) > at > com.google.inject.servlet.Gui
[appengine-java] Unable to connect to repository http://dl.google.com/eclipse/plugin/3.6/content.xml
when I try to install GWT for eclipse through http://dl.google.com/eclipse/plugin/3.6 I see this error: Unable to connect to repository http://dl.google.com/eclipse/plugin/3.6/content.xml Unable to connect to repository http://dl.google.com/eclipse/plugin/3.6/content.xml Connection timed out: connect how can i solve this problem? -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
