Configure Json serializer instead of default jersey?

Question

I use jersey to implement a RESTful web service. Now the MediaType to which I am returning the data is JSON.

@GET @Produces({MediaType.APPLICATION_JSON }) public Response service() { return Response .ok(entity) .header(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON) .build(); } 

Here I set CONTENT_TYPE to json and my entity will be converted to json from the Jersey framework.

Now I want to customize my json response.

For example: I want to delete empty elements or change the key name of my Json object. Default jersey json conversion:

 { "cinter" : { "state" : 1, "checks" : 10, } } 

What I want:

 { "cin" : { "st" : 1, "cs" : 10, } } 

I know that I can use the Jackson library for my own ObjectMapper to customize my Json to suit my needs.

But is this the standard way to do this if I want the JSON conversion to be a different way than the default conversion in Jersey?

Or can I change parametric objects in ObjectMapper in Jersey ??

Should I use my own ObjectMapper ?

Answer 1

Here are my thoughts on your options. First of all

So, for every other answer, should I configure ObjectMapper differently?

If you want to use both versions of json in different places like

 public Response getObject() // returns {"cinter" : {"state" : 1,"checks" : 10}} public Response getShortNamesObject() // returns {"cin" : {"st" : 1,"cs" : 10}} 

Than yep, you need to use multiple ObjectMappers .

But if you just want to use one view all over the world, then you can probably set up Jackson once with a custom mixin for your classes. In any case, here's how you can do both: And let's look at a simple case using just one version of json

 public class TestBean { private String name; private int id; //getters and setters } public interface TestBeanMixin { @JsonProperty("short_field_name") String getName(); @JsonProperty("short_field_id") int getId(); } @Provider @Priority(1) public class MixInJacksonJsonProvider extends JacksonJaxbJsonProvider { private static final ObjectMapper mapper = createMapper(); public MixInJacksonJsonProvider() { setMapper(mapper); } private static ObjectMapper createMapper() { final ObjectMapper result = new ObjectMapper(); result.addMixIn(TestBean.class, TestBeanMixin.class); return result; } } 

This code will generate short names for POJO fields everywhere. and to implement different behavior for different requests, we need to add a new user annotation, for example:

 @Retention(RetentionPolicy.RUNTIME) @Target({ElementType.METHOD, ElementType.TYPE}) public @interface MixIn {} 

The controller will look like this:

 @Path("test") public class MyResource { @GET @MixIn // <== Here is important part @Produces(MediaType.APPLICATION_JSON ) public Response getShortName() { return Response.ok(demoObj()).build(); } @POST @Produces(MediaType.APPLICATION_JSON ) public Response postLongName() { return Response.ok(demoObj()).build(); } } 

And our MixInJacksonJsonProvider will have 2 more @Override :

  //.. same as before @Override public boolean isReadable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) { return super.isReadable(type, genericType, annotations, mediaType) && hasMixInAnnotation(annotations); } @Override public boolean isWriteable(Class<?> type, Type genericType, Annotation[] annotations, MediaType mediaType) { return super.isWriteable(type, genericType, annotations, mediaType) && hasMixInAnnotation(annotations); } public static boolean hasMixInAnnotation(Annotation[] annotations){ for(Annotation annotation: annotations){ if (annotation instanceof MixIn){ return true; } } return false; } } 

Here is the demo code for the game: https://github.com/varren/jersey2-jacksonsetup/tree/master/src/main/java/ru/varren