Jersey 2.0 and Moxy Internal Server Error But No Server Log

Question

I followed the Jersey 2.0 document (https://jersey.java.net/documentation/latest/user-guide.html#json.moxy), modified pom.xml, included jersey-media-moxy artifact, compiled and installed. I could get basic POJO to JSON mapping work for both Produces and Consumes cases.

However, when I tried with some POJO with complex data type as resource return type, I got a lot Status 500 Internal Server Error but without any server log. It is very annoying. Does anybody know if it is a bug or I missed something in configuration?

By the way, in order to use Moxy mapping for a POJO object, the POJO needs to have a empty parameter constructor. Are there any other requirements?

Answer 1

I had the same problem and found this post:

• http://jersey.576304.n2.nabble.com/Missing-MOXy-Log-Messages-In-Tomcat-td7580992.html

The author implemented ApplicationEventListener to log the exceptions thrown by Moxy. This is my implementation (needs to be registered in your application):

public class ExceptionListener implements ApplicationEventListener {

    @Override
    public void onEvent(ApplicationEvent event) {

    }

    @Override
    public RequestEventListener onRequest(RequestEvent requestEvent) {
        return new ExceptionRequestEventListener();
    }

    public static class ExceptionRequestEventListener implements RequestEventListener{
        private final Logger logger;

        public ExceptionRequestEventListener(){
            logger = Logger.getLogger(getClass());
        }

        @Override
        public void onEvent(RequestEvent event) {
            switch (event.getType()){
                case ON_EXCEPTION:
                    Throwable t = event.getException();
                    logger.error("Found exception for requestType: "+event.getType(), t);
            }
        }
    }
}

Answer 2

The official Jersey examples that demonstrate how to integrate EclipseLink MOXy can be found at the following link:

• https://github.com/jersey/jersey/tree/master/examples/json-moxy

Where to find the stacktrace for the internal server error will depend upon your setup, can you provide additional information about yours?

Using the above example if I remove the default constructor from the org.glassfish.jersey.examples.jsonmoxy.TestBean class I will get the following exceptions when running mvn test. One of them is good and the other is bad. I'm going to follow up with the Jersey lead to work out the proper behaviour.

Bad Exception

testGet(org.glassfish.jersey.examples.jsonmoxy.JsonResourceTest)  Time elapsed: 0.507 sec  <<< ERROR!
javax.ws.rs.InternalServerErrorException: HTTP 500 Internal Server Error
    at org.glassfish.jersey.client.JerseyInvocation.convertToException(JerseyInvocation.java:904)
    at org.glassfish.jersey.client.JerseyInvocation.translate(JerseyInvocation.java:749)
    at org.glassfish.jersey.client.JerseyInvocation.access$500(JerseyInvocation.java:88)
    at org.glassfish.jersey.client.JerseyInvocation$2.call(JerseyInvocation.java:650)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:228)
    at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:426)
    at org.glassfish.jersey.client.JerseyInvocation.invoke(JerseyInvocation.java:646)
    at org.glassfish.jersey.client.JerseyInvocation$Builder.method(JerseyInvocation.java:375)
    at org.glassfish.jersey.client.JerseyInvocation$Builder.get(JerseyInvocation.java:275)
    at org.glassfish.jersey.examples.jsonmoxy.JsonResourceTest.testGet(JsonResourceTest.java:76)

Good Exception

roundTripTest(org.glassfish.jersey.examples.jsonmoxy.JsonResourceTest)  Time elapsed: 0.048 sec  <<< ERROR!
javax.ws.rs.WebApplicationException: HTTP 500 Internal Server Error
    at org.eclipse.persistence.exceptions.JAXBException.factoryMethodOrConstructorRequired(JAXBException.java:144)
    at org.eclipse.persistence.jaxb.compiler.AnnotationsProcessor.finalizeProperties(AnnotationsProcessor.java:896)
    at org.eclipse.persistence.jaxb.compiler.AnnotationsProcessor.processClassesAndProperties(AnnotationsProcessor.java:282)
    at org.eclipse.persistence.jaxb.compiler.Generator.<init>(Generator.java:150)
    at org.eclipse.persistence.jaxb.JAXBContext$TypeMappingInfoInput.createContextState(JAXBContext.java:1017)
    at org.eclipse.persistence.jaxb.JAXBContext.<init>(JAXBContext.java:174)
    at org.eclipse.persistence.jaxb.JAXBContextFactory.createContext(JAXBContextFactory.java:165)
    at org.eclipse.persistence.jaxb.JAXBContextFactory.createContext(JAXBContextFactory.java:152)
    at org.eclipse.persistence.jaxb.JAXBContextFactory.createContext(JAXBContextFactory.java:112)
    at org.eclipse.persistence.jaxb.JAXBContextFactory.createContext(JAXBContextFactory.java:102)
    at org.eclipse.persistence.jaxb.rs.MOXyJsonProvider.getJAXBContext(MOXyJsonProvider.java:302)
    at org.eclipse.persistence.jaxb.rs.MOXyJsonProvider.writeTo(MOXyJsonProvider.java:787)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.aroundWriteTo(WriterInterceptorExecutor.java:194)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:139)
    at org.glassfish.jersey.filter.LoggingFilter.aroundWriteTo(LoggingFilter.java:268)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:139)
    at org.glassfish.jersey.message.internal.MessageBodyFactory.writeTo(MessageBodyFactory.java:1005)
    at org.glassfish.jersey.client.ClientRequest.writeEntity(ClientRequest.java:430)
    at org.glassfish.jersey.client.HttpUrlConnector._apply(HttpUrlConnector.java:290)
    at org.glassfish.jersey.client.HttpUrlConnector.apply(HttpUrlConnector.java:203)
    at org.glassfish.jersey.client.ClientRuntime.invoke(ClientRuntime.java:215)
    at org.glassfish.jersey.client.JerseyInvocation$2.call(JerseyInvocation.java:650)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:315)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:297)
    at org.glassfish.jersey.internal.Errors.process(Errors.java:228)
    at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:426)
    at org.glassfish.jersey.client.JerseyInvocation.invoke(JerseyInvocation.java:646)
    at org.glassfish.jersey.client.JerseyInvocation$Builder.method(JerseyInvocation.java:402)
    at org.glassfish.jersey.client.JerseyInvocation$Builder.post(JerseyInvocation.java:305)
    at org.glassfish.jersey.examples.jsonmoxy.JsonResourceTest.roundTripTest(JsonResourceTest.java:84)

---

UPDATE

Starting with EclipseLink 2.5.1 you can use MOXyJsonProvider standalone to test your model.

import java.lang.reflect.Field;
import java.util.*;
import org.eclipse.persistence.jaxb.rs.MOXyJsonProvider;

public class Demo {

    private List<Foo> foos;

    public static void main(String[] args) throws Exception {
        MOXyJsonProvider moxyJsonProvider = new MOXyJsonProvider();

        Field field = Demo.class.getDeclaredField("foos");

        List<Foo> foos = new ArrayList<Foo>(1);
        Foo foo = new Foo();
        foo.setBar("Hello World");
        foos.add(foo);

        moxyJsonProvider.writeTo(foos, field.getType(), field.getGenericType(), null, null, null, System.out);
    }

}