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

[Alex Borschenko]

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"
class="org.apache.axis2.json.gson.rpc.JsonRpcMessageReceiver"  />
        <messageReceiver mep="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':'***@domain.com'}, {'password':'secret'}]}"
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

[robertlazarski]

Post by Alex Borschenko
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.
<messageFormatter contentType="application/json"
class="org.apache.axis2.json.gson.JsonFormatter" />
<messageBuilder contentType="application/json"
class="org.apache.axis2.json.gson.JsonBuilder" />
<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>
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 LoginResponseWSBean implements Serializable {
private boolean loggedIn = false;
private String message = "";
private String stackTrace = "";
public LoginResponseWSBean(boolean loggedIn, String message, String stackTrace) {
this.loggedIn = loggedIn;
this.message = message;
this.stackTrace = stackTrace;
}
public LoginResponseWSBean() {
}
....
}
{'password':'secret'}]}"
http://localhost:8080/axis2/services/LoginWSManager/login
{"Fault":{"faultcode":"soapenv:Server","faultstring":"java.lang.NullPointerException","detail":""}}
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

[Alex Borschenko]

On Thu, Aug 30, 2018 at 2:46 PM Alex Borschenko
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.
        <messageFormatter contentType="application/json"
class="org.apache.axis2.json.gson.JsonFormatter" />
<messageBuilder contentType="application/json"
class="org.apache.axis2.json.gson.JsonBuilder" />
<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>
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() {
}
....
}
curl -X POST -H "Content-Type: application/json" -d
http://localhost:8080/axis2/services/LoginWSManager/login
{"Fault":{"faultcode":"soapenv:Server","faultstring":"java.lang.NullPointerException","detail":""}}
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.