Jackson adds backslash in json

Question

I'm building REST service on Jersey and using Jackson to produce JSON from java classes of my model. Model with absolutely simple values, I think this is the most typical case. But I get strange result:

[{\"name\":\"Nick\",\"role\":\"admin\",\"age\":\"32\",\"rating\":47}] 

My expecting result:

[{"name":"Nick","role":"admin","age":"32","rating":47}] 

My source values of fields does NOT contains any special characters. These are simple words.

There're my Java classes. Entity:

public class User {    private String name;    private String role;    private String age;    private Integer rating; 

Class of rest service:

@ServiceConfig(contextName = "myContext") @Path("/myrest") public class MyRestService {    private static final String JSON_CONTENT_TYPE = MediaType.APPLICATION_JSON + ";charset=UTF-8";    @Context   protected HttpServletResponse response;    @GET   @Path("/users")   @OpenTransaction   @Produces({MediaType.APPLICATION_JSON})   public String findUsers(@QueryParam("department") String department) {      response.setContentType(JSON_CONTENT_TYPE);     PDTResponse.status(response).sendStatus(Response.Status.OK.getStatusCode());      List<User> users = new ArrayList<>();     users.add(new User("Nick", "admin", "32", 47));      String jsonInString;     ObjectMapper mapper = new ObjectMapper();     try {         jsonInString = mapper.writeValueAsString(users);     } catch (JsonProcessingException ex) {         jsonInString = "thrown exception: " + ex.getMessage();     }     return jsonInString; } 

I've tried to use annotation @JsonRawValue for string properties:

@JsonRawValue private String name; 

But result in this case was:

[{\"name\":Nick,\"role\":admin,\"age\":32,\"rating\":47}] 

And I expect:

[{"name":"Nick","role":"admin","age":"32","rating":47}] 

It's obvious that Jackson somehow escapes the quotes in result json of response. But why does it do it, and most importantly how to avoid that? By themselves they are just strings! Without any quotes or special characters.

I use Java 7 and Jackson 2.6.1. And Postman to test result. Any ideas for fix of my problem?

Answer 1

You can configure the ObjectMapper:

final ObjectMapper mapper = new ObjectMapper(); mapper.configure(JsonGenerator.Feature.QUOTE_FIELD_NAMES, false); mapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true); String jsonUsers = mapper.writeValueAsString(users); 

more info here