无法使用Jackson反序列化ZonedDateTime

1 回答

• 1

  我发现了问题，实际上问题不是使用标准的jackson提供程序进行反序列化 . 在我的例子中，我使用Jersey客户端获取JSON，然后使用readEntity方法反序列化 .

  问题是，泽西客户端不知道jsr310模块，因此通过注册已添加jsr310的contextresolver解决了这个问题 . 所以简而言之，如果使用普通的jackson提供程序，则无需为 ZonedDateTime 的seralization和反序列化做任何事情 .

  以下是我在这里提到的参考代码，以便更清晰 .

  public class RESTClientImpl{
  
      /*
       * ***This is very important, JacksonJsonProvider is the implementation of
       * MessageBodyWriter/Reader which is required for "readEntity" method, 
       * else it would throw MessageBodyWriter/Reader not found exception
       * 
       * https://jersey.java.net/documentation/latest/message-body-workers.html#mbw.ex.client.mbr.reg
       *
       * Registering of ObjectMapperContextResolver is important as we have registered JSR310 module there and without registering this, 
       * Jersey client is not aware of JSR310 module, so it will not be able to de-serialize ZonedDateTime
       */
      private final Client client = ClientBuilder.newClient(new ClientConfig().register(LoggingFilter.class)).register(JacksonJsonProvider.class)
              .register(ObjectMapperContextResolver.class);
  
      public User get(URI uri) {
          WebTarget webTarget = client.target(uri);
  
          Invocation.Builder invocationBuilder = webTarget.request(MediaType.APPLICATION_JSON);
          Response response = invocationBuilder.get();    
          User user = response.readEntity(User.class);
          return user;
      }
  }
  
  
  @Provider
  public class ObjectMapperContextResolver implements ContextResolver<ObjectMapper> {  
      private final ObjectMapper MAPPER;
  
      public ObjectMapperContextResolver() {
          MAPPER = new ObjectMapper();
          //This would add JSR310 (Datetime) support while converting date to JSON using JAXRS service
          MAPPER.registerModule(new JavaTimeModule());
          //Below line would disable use of timestamps (numbers), 
          //and instead use a [ISO-8601 ]-compliant notation, which gets output as something like: "1970-01-01T00:00:00.000+0000".
          MAPPER.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
  
          SimpleModule simpleModule = new SimpleModule();
          simpleModule.addDeserializer(Object.class, new ZonedDateTimeDeserializer());
          MAPPER.registerModule(simpleModule);
      }
  
      @Override
      public ObjectMapper getContext(Class<?> type) {
          return MAPPER;
      }  
  }
  

  回复于 2024-04-26T06:11:16+08:00