Returning a list of javax.ws.rs.core.Response resulting in 500

Question

I am trying to return an ArrayList of Response objects from my rest end point.

To do so I am wrapping my result set inside of a Generic Entity object

try {
    GenericEntity<List<Response>> response = new GenericEntity<List<Response>>(responses) {
    };
    return Response.ok(response).build();
} catch (Exception e) {
    e.printStackTrace();
}

No matter what I try I get a 500 back which is frustrating. Is there a way I can get a more definitive answer as to why this is failing? The annotations used for my method are as follows;

@POST
@Path("restendpoint")
@Consumes(MediaType.APPLICATION_JSON)
@Produces(MediaType.APPLICATION_JSON)

Thanks

edit

After adding a custom exception mapper i can see the error is because of this

javax.ws.rs.WebApplicationException: HTTP 500 Internal Server Error
    at org.eclipse.persistence.jaxb.rs.MOXyJsonProvider.writeTo(MOXyJsonProvider.java:951)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.invokeWriteTo(WriterInterceptorExecutor.java:265)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor$TerminalWriterInterceptor.aroundWriteTo(WriterInterceptorExecutor.java:250)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
    at org.glassfish.jersey.server.internal.JsonWithPaddingInterceptor.aroundWriteTo(JsonWithPaddingInterceptor.java:106)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
    at org.glassfish.jersey.server.internal.MappableExceptionWrapperInterceptor.aroundWriteTo(MappableExceptionWrapperInterceptor.java:86)
    at org.glassfish.jersey.message.internal.WriterInterceptorExecutor.proceed(WriterInterceptorExecutor.java:162)
    at org.glassfish.jersey.message.internal.MessageBodyFactory.writeTo(MessageBodyFactory.java:1130)
    at org.glassfish.jersey.server.ServerRuntime$Responder.writeResponse(ServerRuntime.java:711)
    at org.glassfish.jersey.server.ServerRuntime$Responder.processResponse(ServerRuntime.java:444)
    at org.glassfish.jersey.server.ServerRuntime$Responder.process(ServerRuntime.java:434)
    at org.glassfish.jersey.server.ServerRuntime$2.run(ServerRuntime.java:329)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:271)
    at org.glassfish.jersey.internal.Errors$1.call(Errors.java:267)
    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:267)
    at org.glassfish.jersey.process.internal.RequestScope.runInScope(RequestScope.java:317)
    at org.glassfish.jersey.server.ServerRuntime.process(ServerRuntime.java:305)
    at org.glassfish.jersey.server.ApplicationHandler.handle(ApplicationHandler.java:1154)
    at org.glassfish.jersey.servlet.WebComponent.serviceImpl(WebComponent.java:473)
    at org.glassfish.jersey.servlet.WebComponent.service(WebComponent.java:427)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:388)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:341)
    at org.glassfish.jersey.servlet.ServletContainer.service(ServletContainer.java:228)
    at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:769)
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:585)
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1125)
    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
    at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1059)
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
    at org.eclipse.jetty.server.handler.HandlerCollection.handle(HandlerCollection.java:110)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
    at org.eclipse.jetty.server.Server.handle(Server.java:497)
    at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)
    at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:248)
    at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:540)
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:610)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:539)
    at java.lang.Thread.run(Thread.java:744)
Caused by: javax.xml.bind.MarshalException
 - with linked exception:
[Exception [EclipseLink-25007] (Eclipse Persistence Services - 2.6.0.v20150309-bf26070): org.eclipse.persistence.exceptions.XMLMarshalException
Exception Description: A descriptor for class org.glassfish.jersey.message.internal.OutboundJaxrsResponse was not found in the project.  For JAXB, if the JAXBContext was bootstrapped using TypeMappingInfo[] you must call a marshal method that accepts TypeMappingInfo as an input parameter.]
    at org.eclipse.persistence.jaxb.JAXBMarshaller.marshal(JAXBMarshaller.java:487)
    at org.eclipse.persistence.jaxb.rs.MOXyJsonProvider.writeTo(MOXyJsonProvider.java:949)
    ... 40 more
Caused by: Exception [EclipseLink-25007] (Eclipse Persistence Services - 2.6.0.v20150309-bf26070): org.eclipse.persistence.exceptions.XMLMarshalException
Exception Description: A descriptor for class org.glassfish.jersey.message.internal.OutboundJaxrsResponse was not found in the project.  For JAXB, if the JAXBContext was bootstrapped using TypeMappingInfo[] you must call a marshal method that accepts TypeMappingInfo as an input parameter.
    at org.eclipse.persistence.exceptions.XMLMarshalException.descriptorNotFoundInProject(XMLMarshalException.java:154)
    at org.eclipse.persistence.internal.oxm.Context$ContextState.getSession(Context.java:137)
    at org.eclipse.persistence.oxm.XMLContext$XMLContextState.getSession(XMLContext.java:798)
    at org.eclipse.persistence.oxm.XMLContext$XMLContextState.getSession(XMLContext.java:1)
    at org.eclipse.persistence.internal.oxm.Context.getSession(Context.java:458)
    at org.eclipse.persistence.oxm.XMLContext.getSession(XMLContext.java:366)
    at org.eclipse.persistence.oxm.XMLContext.getSession(XMLContext.java:1)
    at org.eclipse.persistence.internal.oxm.XMLMarshaller.marshal(XMLMarshaller.java:582)
    at org.eclipse.persistence.internal.oxm.XMLMarshaller.marshalStreamOrWriter(XMLMarshaller.java:1126)
    at org.eclipse.persistence.internal.oxm.XMLMarshaller.marshal(XMLMarshaller.java:934)
    at org.eclipse.persistence.internal.oxm.XMLMarshaller.marshal(XMLMarshaller.java:877)
    at org.eclipse.persistence.jaxb.JAXBMarshaller.marshal(JAXBMarshaller.java:483)
    ... 41 more

Answer 1

As @simdevmon stated, javax.ws.rs.core.Response is not gonna work for your purposes because once you call build() method, it'll create an outgoing response (OutboundJaxrsResponse) that Jersey uses to send to a client.

This implies that Jersey won't understand, by default, how to marshal/unmarshal its properties when the response is sent through the server.

If you only need the response objects list as a JSON result, another suitable solution would be creating a wrapper class for your list (without final fields nor constructors):

import javax.ws.rs.core.Response;

public class MyResponse {

    private List<Response> responses;

    public List<Response> getResponses() {
        return responses;
    }

    public void setResponses(List<Response> responses) {
        this.responses = responses;
    }

}

and your rest call to handle this object instead:

try {
    List<Response> responses = new ArrayList<>();
    responses.add(Response.ok().build());
    responses.add(Response.notModified().build());
    responses.add(Response.noContent().build());

    MyResponse myResponse = new MyResponse();
    myResponse.setResponses(responses);

    return Response.ok(new GenericEntity<MyResponse>(myResponse) {}).build();
} catch (Exception e) {
    e.printStackTrace();
}

---

This will generate the following JSON output:

{
  "responses": [
    "OutboundJaxrsResponse{status=200, reason=OK, hasEntity=false, closed=false, buffered=false}",
    "OutboundJaxrsResponse{status=304, reason=Not Modified, hasEntity=false, closed=false, buffered=false}",
    "OutboundJaxrsResponse{status=204, reason=No Content, hasEntity=false, closed=false, buffered=false}"
  ]
}