5 Replies Latest reply on Jun 5, 2012 9:17 AM by Christian Sadilek

    Errai Null Pointer Exception Transforming List<Byte> to JSON

    Matthew Casperson Newbie

      The following code in the org.jboss.errai.enterprise.client.jaxrs.JacksonTransformer.toJackson() method is throwing a null pointer error because obj.get(k) is returning a JSONNumber, which means the isString() method is returning null. Is this a bug, or have I done something wrong?

       

              else if (k.equals(NUM_VALUE)) {
                if (parent != null) {
                  String numValue = obj.get(k).isString().stringValue();
                  parent.put(key, new JSONNumber(Double.parseDouble(numValue)));
      
      
        • 1. Re: Errai Null Pointer Exception Transforming List<Byte> to JSON
          Christian Sadilek Master

          Hi Matthew,

           

          Yes, this was a bug. It's fixed now and a new 2.1-SNAPSHOT of errai-jaxrs-client has been published.

           

          Thanks,

          Christian

          • 2. Re: Errai Null Pointer Exception Transforming List<Byte> to JSON
            Matthew Casperson Newbie

            EDIT: Ignore that last post. It is probably to do with converting a file into a byte array.

             

            However, when sending a simple List<Byte> to the server, I get this on the server end:

             

            Caused by: org.codehaus.jackson.map.JsonMappingException: Can not deserialize instance of java.util.List out of VALUE_NUMBER_INT token
             at [Source: org.apache.catalina.connector.CoyoteInputStream@a82ea; line: 1, column: 17]
                      at org.codehaus.jackson.map.JsonMappingException.from(JsonMappingException.java:160) [jackson-mapper-asl-1.6.3.jar:1.6.3]
                      at org.codehaus.jackson.map.deser.StdDeserializationContext.mappingException(StdDeserializationContext.java:194) [jackson-mapper-asl-1.6.3.jar:1.6.3]
                      at org.codehaus.jackson.map.deser.CollectionDeserializer.deserialize(CollectionDeserializer.java:103) [jackson-mapper-asl-1.6.3.jar:1.6.3]
                      at org.codehaus.jackson.map.deser.CollectionDeserializer.deserialize(CollectionDeserializer.java:93) [jackson-mapper-asl-1.6.3.jar:1.6.3]
                      at org.codehaus.jackson.map.deser.CollectionDeserializer.deserialize(CollectionDeserializer.java:25) [jackson-mapper-asl-1.6.3.jar:1.6.3]
                      at org.codehaus.jackson.map.deser.SettableBeanProperty.deserialize(SettableBeanProperty.java:149) [jackson-mapper-asl-1.6.3.jar:1.6.3]
                      at org.codehaus.jackson.map.deser.SettableBeanProperty$MethodProperty.deserializeAndSet(SettableBeanProperty.java:237) [jackson-mapper-asl-1.6.3.jar:1.6.3]
                      at org.codehaus.jackson.map.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:496) [jackson-mapper-asl-1.6.3.jar:1.6.3]
                      at org.codehaus.jackson.map.deser.BeanDeserializer.deserialize(BeanDeserializer.java:350) [jackson-mapper-asl-1.6.3.jar:1.6.3]
                      at org.codehaus.jackson.map.ObjectMapper._readValue(ObjectMapper.java:1961) [jackson-mapper-asl-1.6.3.jar:1.6.3]
                      at org.codehaus.jackson.map.ObjectMapper.readValue(ObjectMapper.java:889) [jackson-mapper-asl-1.6.3.jar:1.6.3]
                      at org.codehaus.jackson.jaxrs.JacksonJsonProvider.readFrom(JacksonJsonProvider.java:410) [jackson-jaxrs-1.6.3.jar:1.6.3]
                      at org.jboss.resteasy.core.interception.MessageBodyReaderContextImpl.proceed(MessageBodyReaderContextImpl.java:105) [resteasy-jaxrs-2.2.1.GA.jar:]
                      at org.jboss.resteasy.plugins.interceptors.encoding.GZIPDecodingInterceptor.read(GZIPDecodingInterceptor.java:61) [resteasy-jaxrs-2.2.1.GA.jar:]
                      at org.jboss.resteasy.core.interception.MessageBodyReaderContextImpl.proceed(MessageBodyReaderContextImpl.java:108) [resteasy-jaxrs-2.2.1.GA.jar:]
                      at org.jboss.resteasy.core.MessageBodyParameterInjector.inject(MessageBodyParameterInjector.java:168) [resteasy-jaxrs-2.2.1.GA.jar:]
                      ... 50 more
            
            

             

            The client has dumped the following JSON to the console:

             

            {"^EncodedType":"com.redhat.topicindex.rest.entities.interfaces.RESTImageV1","^ObjectID":"1","filename" : null,"imageData" : {"^EncodedType":"java.util.ArrayList","^ObjectID":"2","^Value":[{"^EncodedType":"java.lang.Byte", "^ObjectID": "84","^NumVal":84},{"^EncodedType":"java.lang.Byte", "^ObjectID": "101","^NumVal":101},{"^EncodedType":"java.lang.Byte", "^ObjectID": "115","^NumVal":115},{"^EncodedType":"java.lang.Byte", "^ObjectID": "116","^NumVal":116}]},"thumbnail" : null,"imageDataBase64" : null,"description" : null,"id" : null,"revision" : null,"configuredParameters" : {"^EncodedType":"java.util.ArrayList","^ObjectID":"3","^Value":["imageData"]},"selfLink" : null,"editLink" : null,"deleteLink" : null,"addLink" : null,"expand" : null,"addItem" : false,"removeItem" : false,"revisions" : null}
            

             

            I'm not sure where the VALUE_NUMBER_INT token is coming from.

            • 3. Re: Errai Null Pointer Exception Transforming List<Byte> to JSON
              Matthew Casperson Newbie

              And using a byte[] instead of a List<Byte> results in the following exception on the client side:

               

              java.lang.ClassCastException: com.google.gwt.json.client.JSONNumber cannot be cast to java.lang.String
                        at com.google.gwt.json.client.JSONNumber.toString(JSONNumber.java)
                        at java.lang.String.valueOf(String.java:2902)
                        at java.lang.StringBuffer.append(StringBuffer.java:232)
                        at com.google.gwt.json.client.JSONArray.toString(JSONArray.java:132)
                        at java.lang.String.valueOf(String.java:2902)
                        at java.lang.StringBuffer.append(StringBuffer.java:232)
                        at com.google.gwt.json.client.JSONObject.toString(JSONObject.java:183)
                        at org.jboss.errai.enterprise.client.jaxrs.JacksonTransformer.toJackson(JacksonTransformer.java:56)
                        at org.jboss.errai.enterprise.client.jaxrs.MarshallingWrapper._toJSON(MarshallingWrapper.java:45)
                        at org.jboss.errai.enterprise.client.jaxrs.MarshallingWrapper.toJSON(MarshallingWrapper.java:32)
                        at org.jboss.errai.enterprise.client.jaxrs.JaxrsProxyLoaderImpl$1RESTInterfaceV1Impl.createJSONImage(JaxrsProxyLoaderImpl.java:1820)
                        at com.redhat.topicindex.extras.client.local.App$6.onLoadEnd(App.java:142)
                        at org.vectomatic.file.events.LoadEndEvent.dispatch(LoadEndEvent.java:53)
                        at org.vectomatic.file.events.LoadEndEvent.dispatch(LoadEndEvent.java:1)
                        at com.google.gwt.event.shared.GwtEvent.dispatch(GwtEvent.java:1)
                        at com.google.web.bindery.event.shared.EventBus.dispatchEvent(EventBus.java:40)
                        at com.google.web.bindery.event.shared.SimpleEventBus.doFire(SimpleEventBus.java:193)
                        at com.google.web.bindery.event.shared.SimpleEventBus.fireEventFromSource(SimpleEventBus.java:96)
                        at com.google.gwt.event.shared.SimpleEventBus.fireEventFromSource(SimpleEventBus.java:62)
                        at com.google.gwt.event.shared.EventBus.castFireEventFromSource(EventBus.java:75)
                        at com.google.gwt.event.shared.SimpleEventBus.fireEventFromSource(SimpleEventBus.java:67)
                        at org.vectomatic.file.FileReader.fireEvent(FileReader.java:286)
                        at com.google.gwt.event.dom.client.DomEvent.fireNativeEvent(DomEvent.java:116)
                        at org.vectomatic.file.FileReader.dispatch(FileReader.java:281)
                        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
                        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
                        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
                        at java.lang.reflect.Method.invoke(Method.java:601)
                        at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
                        at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
                        at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172)
                        at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:292)
                        at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:546)
                        at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:363)
                        at java.lang.Thread.run(Thread.java:722)
              
              
              • 4. Re: Errai Null Pointer Exception Transforming List<Byte> to JSON
                Matthew Casperson Newbie

                OK, take two produces the client exception:

                 

                com.google.gwt.dev.shell.HostedModeException: Something other than an int was returned from JSNI method '@com.google.gwt.json.client.JSONArray::size()': JS value of type Java Object com.google.gwt.dev.shell.JsValueOOPHM$DispatchObjectOOPHM, expected int
                          at com.google.gwt.dev.shell.JsValueGlue.getIntRange(JsValueGlue.java:266)
                          at com.google.gwt.dev.shell.JsValueGlue.get(JsValueGlue.java:144)
                          at com.google.gwt.dev.shell.ModuleSpace.invokeNativeInt(ModuleSpace.java:247)
                          at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeInt(JavaScriptHost.java:75)
                          at com.google.gwt.json.client.JSONArray.size(JSONArray.java)
                          at org.jboss.errai.enterprise.client.jaxrs.JacksonTransformer.toJackson(JacksonTransformer.java:104)
                          at org.jboss.errai.enterprise.client.jaxrs.JacksonTransformer.toJackson(JacksonTransformer.java:137)
                          at org.jboss.errai.enterprise.client.jaxrs.JacksonTransformer.toJackson(JacksonTransformer.java:54)
                          at org.jboss.errai.enterprise.client.jaxrs.MarshallingWrapper._toJSON(MarshallingWrapper.java:45)
                          at org.jboss.errai.enterprise.client.jaxrs.MarshallingWrapper.toJSON(MarshallingWrapper.java:32)
                          at org.jboss.errai.enterprise.client.jaxrs.JaxrsProxyLoaderImpl$1RESTInterfaceV1Impl.createWithByteArray(JaxrsProxyLoaderImpl.java:73)
                          at com.redhat.topicindex.extras.client.local.App$1.onClick(App.java:72)
                          at com.google.gwt.event.dom.client.ClickEvent.dispatch(ClickEvent.java:54)
                          at com.google.gwt.event.dom.client.ClickEvent.dispatch(ClickEvent.java:1)
                          at com.google.gwt.event.shared.GwtEvent.dispatch(GwtEvent.java:1)
                          at com.google.web.bindery.event.shared.EventBus.dispatchEvent(EventBus.java:40)
                          at com.google.web.bindery.event.shared.SimpleEventBus.doFire(SimpleEventBus.java:193)
                          at com.google.web.bindery.event.shared.SimpleEventBus.fireEvent(SimpleEventBus.java:88)
                          at com.google.gwt.event.shared.HandlerManager.fireEvent(HandlerManager.java:127)
                          at com.google.gwt.user.client.ui.Widget.fireEvent(Widget.java:129)
                          at com.google.gwt.event.dom.client.DomEvent.fireNativeEvent(DomEvent.java:116)
                          at com.google.gwt.user.client.ui.Widget.onBrowserEvent(Widget.java:177)
                          at com.google.gwt.user.client.DOM.dispatchEventImpl(DOM.java:1351)
                          at com.google.gwt.user.client.DOM.dispatchEvent(DOM.java:1307)
                          at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
                          at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
                          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
                          at java.lang.reflect.Method.invoke(Method.java:601)
                          at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
                          at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
                          at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172)
                          at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:337)
                          at com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:218)
                          at com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:136)
                          at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:561)
                          at com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:269)
                          at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:91)
                          at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
                          at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:213)
                          at sun.reflect.GeneratedMethodAccessor33.invoke(Unknown Source)
                          at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
                          at java.lang.reflect.Method.invoke(Method.java:601)
                          at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
                          at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
                          at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172)
                          at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:292)
                          at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:546)
                          at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:363)
                          at java.lang.Thread.run(Thread.java:722)
                
                

                 

                However, this appears to be a string limit or something similar. I am trying to populate the byte[] from the contents of a file (loaded using lib-gwt-file). When the byte[] is only a few elements long, the REST object is serialized and set off fine. I guess I'll have to abandon the client side only approach, and upload the file to a server side component which can then call the REST server.

                 

                Is there some practical limit to how much data Errai can serialize as JSON?

                • 5. Re: Errai Null Pointer Exception Transforming List<Byte> to JSON
                  Christian Sadilek Master

                  Ah yes, this is not a limitation of Errai. It's a problem with DevMode and (some versions of) Chrome, IIRC. You should not see this error in production mode.