Jersey 2.2: output xml OK, but fails on json - json

Question

I've run into a weird problem.
I use Jersey 2.2 to do my restful web services (with jersey-media-moxy).
If I produce my output as application/xml, it runs fine.
But if produce my output as application/json, I get "Internal Server Error 500".
My dependency settings in ivy.xml are:
<dependency org="org.glassfish.jersey.core" name="jersey-server" rev="2.2"/>
<dependency org="org.glassfish.jersey.containers" name="jersey-container-servlet-core" rev="2.2"/>
<dependency org="org.glassfish.jersey.media" name="jersey-media-moxy" rev="2.2"/>
My service class is:
#Path("/projects/{companykey: [0-9]*}")
#Produces({MediaType.APPLICATION_XML, MediaType.APPLICATION_JSON})
public class ProjectResource {
private static Logger logger = Logger.getLogger(ProjectResource.class);
private final Application app = Application.getInstance();
#GET
public List<ProjectBase> getProjectBases(
#PathParam("companykey") String companyKeyStr) {
...
}
#GET
#Path("/{projectkey: [0-9]*}")
public ProjectBase getProjectBase(
#PathParam("companykey") String companyKeyStr,
#PathParam("projectkey") String projectKeyStr) {
int companyKey = Integer.valueOf(companyKeyStr);
int projObjKey = Integer.valueOf(projectKeyStr);
logger.debug(MessageFormat.format("get project {1} of company {0}",
companyKey, projObjKey));
ProjectBase project = null;
try {
project = app.getProjectIF().getProjectBase(companyKey, projObjKey);
if (project == null) throw new WebApplicationException(404);
return project;
} catch (ServerException se) {
logger.warn("get project fails ! " + se);
throw new WebApplicationException(500);
}
}
...
}
//class end
If I ask for the xml output (visit http://biz.loc.net:8080/tm/rest/projects/100/104), I get:
<projectBase>
<_checkTopicAccess>false</_checkTopicAccess>
<_checkTaskAccess>false</_checkTaskAccess>
....
If I ask for the json output, I get:
HTTP Status 500 - Internal Server Error
type Status report
message Internal Server Error
description The server encountered an internal error (Internal Server Error) that prevented it from fulfilling this request.
I do not find any error messages in my app's log file or Tomcat's log file, so I have no
idea what is going on.
Does anyone know any possible reason for this problem? Really appreciate ...

Answer 1

Can you show the entity code? Are you missing an empty constructor?

Answer 2

Thanks for your help, the following code snippet is my entity clas:
#XmlRootElement
public class ProjectBase implements UdaEnabled, SdaEnabled, FormBean {
private int projObjKey;
private String projName;
//...
private Timestamp createdAt;
//...
//...
#XmlElement(name = "createdAt")
#XmlJavaTypeAdapter(TimestampAdapter.class)
public Timestamp getCreatedAt() {
return createdAt;
}
// non-args Constructor
public ProjectBase() {
init();
}
}
It does has an empty constructor, although these's a init() inside.
As I said, I think it is weird because producing xml is OK.