REST返回Java对象，而不是转换JSON

Question

我使用@Produces（MediaType.APPLICATION_JSON）返回JSON，但是它将以下信息作为Java对象而不是正确的JSON返回

任何想法我如何获得正确的数据，而不是班级或列表信息？

期望格式

{“ page”：1，“ pageSize”：20，“ totalResults”：4547，“ sortField”：“ logId”，“ sortDirection”：“ desc”，“ list”：[{“ logId”：4548，“ loggingFor“：” MAXIMO_ACCNT“，” loggedName“：” AdamNev“，”详细信息“：”：Mozilla /“，” loggedDate“：1588394266000，” totalCount“：null}]}

生成的输出

{“列表”：[“ mycompany.class.LogUtil@2bd24315”，“ mycompany.class.LogUtil@5b71cbba”，“ mycompany.class.LogUtil@7679315d”，“ mycompany.class.LogUtil@2591e588”，“ mycompany .class.LogUtil @ 1ce2c0c4“，” mycompany.class.LogUtil@499be4f9“，” mycompany.class.LogUtil@7657d74e“，” mycompany.class.LogUtil@5c40d1a9“，” mycompany.class.LogUtil@562ede05“，” mycompany。 .class.LogUtil @ 40845415“，” mycompany.class.LogUtil@82106ec“，” mycompany.class.LogUtil@52b643d8“，” mycompany.class.LogUtil@72c8717d“，” mycompany.class.LogUtil@100ea7cd“，” mycompany .class.LogUtil @ 1098c546“，” mycompany.class.LogUtil@7050ec0e“，” mycompany.class.LogUtil@412238e0“，” mycompany.class.LogUtil@24f7cfc6“，” mycompany.class.LogUtil@72939ceb“，” mycompany .class.LogUtil @ 5543e2b“]，” page“：1，” pageSize“：20，” sortDirection“：” desc“，” sortField“：” logId“，” totalResults“：4547}]

从数据库中获取数据的Java类代码片段

    GET
    @Path("/list")
    @Produces(MediaType.APPLICATION_JSON)
    public LogDataWrapper getLogs(@Context UriInfo uriInfo) throws JSONException {

       LogDataWrapper<logDataUtil> logDataWrapper =
       new LogDataWrapper<logDataUtil>();

       try {
       MultivaluedMap params = uriInfo.getQueryParameters();
       StringBuilder builder = new StringBuilder();
       for (Object key : params.keySet()) {
      builder.append(key)
       .append(":")
       .append(params.getFirst(key))
       .append("\n");
       }
       JSONObject inputJSON = new JSONObject(builder.toString().substring(builder.toString().indexOf('{')));

       Integer page = inputJSON.getInt("page"); //setting parameter from .JS file
       Integer pageSize = inputJSON.getInt("pageSize"); //setting parameter from .JS file


       if (inputJSON.has("sort")) {

       JSONArray sorts = inputJSON.getJSONArray("sort");
       for (int i = 0; i < sorts.length(); i++) {

       JSONObject jo = (JSONObject) sorts.get(i);
      logDataWrapper.setSortField(jo.getString("field")); //setting parameter from .JS file
      logDataWrapper.setSortDirection(jo.getString("dir")); //setting parameter from .JS file
       }
       }

      logDataWrapper.setPage(page); //setting parameter from .JS file
      logDataWrapper.setPageSize(pageSize); //setting parameter from .JS file
       } catch (Exception e) {
      log.error("Exce " + e.getMessage());
      e.printStackTrace();
       }

       return getLogs(logDataWrapper); the below is the method

    private LogDataWrapper<logDataUtil> getLogs(LogDataWrapper<logDataUtil> wrapper) throws JSONException {    
            //wrapper.setTotalResults(countLog());
            wrapper.setList(getLogsList(wrapper)); // the below gets data from database
            return wrapper;
    }
   private List<logDataUtil> getLogsList(LogDataWrapper<logDataUtil> wrapper) 
   throws JSONException {
        List<logDataUtil> result = null;
        try {
            CriteriaBuilder criteriaBuilder = getEntityManager().getCriteriaBuilder();
            CriteriaQuery<logDataUtil> criteriaQuery =
                criteriaBuilder.createQuery(logDataUtil.class);

            Root<MyLog> root = criteriaQuery.from(MyLog.class);

            Join<MyLog, Employee> joinLoggedFor = root.join(MyLog_.employee, JoinType.LEFT);

            Join<MyLog, Employee> joinLoggedBy = root.join(MyLog_.employee1, JoinType.LEFT);

            Join<MyLog, ApplicationList> joinAppName =

                root.join(MyLog_.applicationList, JoinType.LEFT);

            criteriaQuery.multiselect(root.get(MyLog_.logId), joinLoggedFor.get(Employee_.employeeNumber),

                                      criteriaBuilder.selectCase().when(criteriaBuilder.equal(joinLoggedFor.get(Employee_.employeeNumber),

                                                                                              "Self Reset"),

                                                                        "Self Reset").otherwise(joinLoggedFor.get(Employee_.longName)),

            TypedQuery<logDataUtil> typedQuery = getEntityManager().createQuery(criteriaQuery);

            int start = (wrapper.getPage() - 1) * wrapper.getPageSize();

            typedQuery.setFirstResult((start));

            typedQuery.setMaxResults(wrapper.getPageSize());

            result = typedQuery.getResultList();

        } catch (Exception e) {

            log.error("Exception from  getPasswordResetLogsList " + e.getMessage());

        }

        return result;

    }

Answer 1

您需要为您的自定义类型（在您的情况下为logUtil）编写MessageBodyWriter，这将有助于将对象输出为JSON。

请参阅：https://eclipse-ee4j.github.io/jersey.github.io/documentation/latest/message-body-workers.html