Jackson在json中添加反斜杠

Question

我正在Jersey上构建REST服务，并使用Jackson从我模型的java类生成JSON。模型具有绝对简单的值，我认为这是最典型的情况。但我得到了奇怪的结果：

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

我的期待结果：

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

我的字段源值不包含任何特殊字符。这些是简单的单词。

这是我的Java类。实体：

public class User {

  private String name;

  private String role;

  private String age;

  private Integer rating;

Rest服务等级：

@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;
}

我尝试使用注释JsonRawValue来表示字符串属性：

@JsonRawValue
private String name;

但在这种情况下，结果是：

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

我期望：

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

很明显，Jackson以某种方式逃避了响应结果json中的引用。但它为什么这样做，最重要的是如何避免？它们本身就是绳子！没有任何引号或特殊字符。

我使用Java 7和Jackson 2.6.1。和邮递员测试结果。有解决我问题的办法吗？

Answer 1

这样做。

ObjectMapper mapper = new ObjectMapper();
mapper.getFactory().setCharacterEscapes(new JsonUtil().new CustomCharacterEscapes());
ObjectWriter writer = mapper.writer();

String jsonDataObject = mapper.writeValueAsString(configMap);       

public class CustomCharacterEscapes extends CharacterEscapes {

private final int[] _asciiEscapes;

    public CustomCharacterEscapes() {
       _asciiEscapes = standardAsciiEscapesForJSON();
       //By default the ascii Escape table in jackson has " added as escape string
       //overwriting that here.
       _asciiEscapes['"'] = CharacterEscapes.ESCAPE_NONE;
     }

     @Override
     public int[] getEscapeCodesForAscii() {
       return _asciiEscapes;
     }

     @Override
     public SerializableString getEscapeSequence(int i) {
       return null;
    }
  }

Answer 2

java中的所有字符串都必须在其中转义引号。所以jsonInString应该有斜杠。当您输出jsonInString时，虽然它不应该有引号。您是在调试器中查看它还是什么？

Answer 3

您可以配置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);

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