REST service : No message body writer has been found

[Bertrand TROLARD]

Hi,

I got a problem with a REST service when I use CXF 3.x, it's working 
fine with CXF 2.7.
"No message body writer has been found for class java.lang.Integer"
Response-Code: 500
Content-Type: text/plain
Headers: {Content-Type=[plain/text], Date=[Fri, 14 Sep 2018 13:41:18 GMT]}
Payload: No message body writer has been found for class 
java.lang.Integer, ContentType: plain/text


I got this error with this function :
    @POST
    @Path("/state/")
    public int getStateBatchResult(@QueryParam("uid") String id);


I use SPRING to define the service
    <jaxrs:server xmlns:tns="http://www.xxx/AnalyzeRESTService"; 
id="restServer" address="/asynchrone" serviceName="tns:AnalyzeREST" >
        <jaxrs:serviceBeans>
            <ref bean="serviceImplCXF"/>
        </jaxrs:serviceBeans>
        <jaxrs:features>
            <bean class="org.apache.cxf.feature.LoggingFeature" />
        </jaxrs:features>
        <jaxrs:dataBinding>
            <bean class="org.apache.cxf.jaxb.JAXBDataBinding"/>
        </jaxrs:dataBinding>
    </jaxrs:server>

but we have no problem with this one :
    @POST
    @Path("/result/")
    @Produces({"plain/text"})
    public DataHandler getBatchResultDH(@QueryParam("uid") String id,
            @QueryParam("comp") int typeCompression);


I test it with eclipse, Java 8, CXF 3.1.4 or 3.0.16

Do I miss some dependencies or something else ?

Thanks,
Bertrand