Re: Axis2 / Java: java.lang.NullPointerException at org.apache.axis2.context.MessageContext.isFault(MessageContext.java:4304)

On 8/31/2018 12:04 AM, robertlazarski wrote:
>
>
> On Thu, Aug 30, 2018 at 2:46 PM Alex Borschenko 
> <[email protected] <mailto:[email protected]>> wrote:
>
>     Hi All!
>
>     I have deployed archive of services which consume/produce XMLs and
>     now I'm trying to add one more service who will consume/produce JSON.
>     It is simple service which operates with POJOs.
>
>     To enable JSON operations I added to axis2.xml:
>
>             <messageFormatter contentType="application/json"
>     class="org.apache.axis2.json.gson.JsonFormatter" />
>
>     <messageBuilder contentType="application/json"
>     class="org.apache.axis2.json.gson.JsonBuilder" />
>
>     In services XML I have declared my service:
>
>     <service name="LoginWSManager">
>         <Description>
>             This is a sample service to test json implementation
>         </Description>
>         <messageReceivers>
>             <messageReceiver mep="http://www.w3.org/ns/wsdl/in-out"
>     <http://www.w3.org/ns/wsdl/in-out>
>     class="org.apache.axis2.json.gson.rpc.JsonRpcMessageReceiver" />
>             <messageReceiver mep="http://www.w3.org/ns/wsdl/in-only"
>     <http://www.w3.org/ns/wsdl/in-only>
>     class="org.apache.axis2.json.gson.rpc.JsonInOnlyRPCMessageReceiver"/>
>         </messageReceivers>
>         <parameter name="ServiceClass"
>     locked="false">security.LoginWSManager</parameter>
>     </service>
>
>     Service code:
>
>     public LoginResponseWSBean login(String email, String password)throws Exception {
>          Application.logger().info("Logging in user email: " + email);
>
>          final LoginResponseWSBean loginResponseWSBean =new LoginResponseWSBean();
>          try {
>              loginBusinessLogic.login(email, password);
>          }catch (Exception e) {
>              loginResponseWSBean.setLoggedIn(false);
>              loginResponseWSBean.setMessage(e.getMessage());
>              loginResponseWSBean.setStackTrace(ExceptionUtils.getStackTrace(e));
>              Application.logger().warning(String.format("Returning: %s", loginResponseWSBean));
>              return loginResponseWSBean;
>          }
>          loginResponseWSBean.setLoggedIn(true);
>          loginResponseWSBean.setMessage(email +" logged in successfully!");
>
>          return loginResponseWSBean;
>     }
>
>     public class LoginResponseWSBeanimplements Serializable {
>
>          private boolean loggedIn =false;
>          private Stringmessage ="";
>          private StringstackTrace ="";
>
>          public LoginResponseWSBean(boolean loggedIn, String message, String stackTrace) {
>              this.loggedIn = loggedIn;
>              this.message = message;
>              this.stackTrace = stackTrace;
>          }
>
>          public LoginResponseWSBean() {
>
>          }
>     ....
>     }
>
>
>     When I call it by this command:
>
>     curl -X POST -H "Content-Type: application/json" -d
>     "{'login':[{'email':'[email protected]'}, {'password':'secret'}]}"
>     <mailto:%7B%27login%27:[%7B%27email%27:%[email protected]%27%7D,%7B%27password%27:%27secret%27%7D]%7D>
>     http://localhost:8080/axis2/services/LoginWSManager/login
>
>     It responds with this message:
>     {"Fault":{"faultcode":"soapenv:Server","faultstring":"java.lang.NullPointerException","detail":""}}
>
>     In tomcat logs I can see this stacktrace:
>
>     30-Aug-2018 23:38:09.137 INFO [http-nio-8080-exec-9]
>     org.apache.catalina.core.StandardWrapperValve.invoke [ERROR]
>     java.lang.NullPointerException
>             at
>     org.apache.axis2.context.MessageContext.isFault(MessageContext.java:4304)
>             at
>     org.apache.axis2.transport.http.CommonsHTTPTransportSender.sendUsingOutputStream(CommonsHTTPTransportSender.java:289)
>             at
>     org.apache.axis2.transport.http.CommonsHTTPTransportSender.invoke(CommonsHTTPTransportSender.java:244)
>             at
>     org.apache.axis2.engine.AxisEngine.send(AxisEngine.java:431)
>             at
>     org.apache.axis2.receivers.AbstractInOutMessageReceiver.invokeBusinessLogic(AbstractInOutMessageReceiver.java:43)
>             at
>     org.apache.axis2.receivers.AbstractMessageReceiver.receive(AbstractMessageReceiver.java:106)
>             at
>     org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:169)
>             at
>     org.apache.axis2.transport.http.HTTPTransportUtils.processHTTPPostRequest(HTTPTransportUtils.java:178)
>             at
>     org.apache.axis2.transport.http.AxisServlet.doPost(AxisServlet.java:163)
>             at
>     javax.servlet.http.HttpServlet.service(HttpServlet.java:648)
>             at
>     javax.servlet.http.HttpServlet.service(HttpServlet.java:729)
>             at
>     org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:292)
>             at
>     org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
>             at
>     org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
>             at
>     org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:240)
>             at
>     org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:207)
>             at
>     org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197)
>             at
>     org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
>             at
>     org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
>             at
>     org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
>             at
>     org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
>             at
>     org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:616)
>             at
>     org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
>             at
>     org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:528)
>             at
>     org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1100)
>             at
>     org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:687)
>             at
>     org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1520)
>             at
>     org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1476)
>             at
>     java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
>             at
>     java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
>             at
>     org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
>             at java.lang.Thread.run(Thread.java:745)
>
>     Please help me find out why it is not processing
>     LoginResponseWSBean response object as expected and generates NPE.
>     Thanx!
>
>     Alex
>
>
> I am planning on a patch for this issue as I am using GSON / Axis2 
> quite a bit in my day job right now. There are a few things I want to 
> discuss with the Axis2 dev team here, including this NPE.
>
> In this case I made this change in the MessageContext.java source. You 
> would have to compile from source to fix it in the short term. I don't 
> know why the Envelope is null here. Making this change had no effect 
> on my existing soap based services but it did fix the GSON services.
>
>     public boolean isFault() {
>         if (getEnvelope() == null) {
>             log.warn(getLogIDString() + ": ****WARNING**** " + 
> myClassName +
>                     " , found null envelope, returning false");
>             return false;
>         }
>         return getEnvelope().hasFault();
>     }
>
> I was wondering if anyone is using GSON with axis2, the docs are 
> something I plan on improving soon and good to know someone else is 
> using this code.
>
> Regards,
> Robert

Hi Robert!

Your solution helped :)
I was already about to try this on my own and your suggestion made me 
stronger in my decision :)

Thanx, mate!

Alex.