使用@JsonCreator和d @JsonProperty未能按预期生成Json响应

Question

I am using JDK 1.6 , Jackson 2.0.5 , Spring 3.0.3 and using jackson annotations to serialize and deserialize json response.

public class MyDate extends java.sql.Date{

  private static SimpleDateFormat simpleDateFormat = new SimpleDateFormat("MM/dd/yyyy");
  private String dateString;

  @JsonCreator
  public MyDate(@JsonProperty("dateString") String date){
        super(simpleDateFormat.parse(date).getTime());
        dateString = date;
  }

  public String getDateString(){
        return dateString;
  }
  private final setDateString(String date){
        // .....
  }
}

I am getting json response message like 1417977000000 , but it should be like 12/08/2014. Do I need to write anything else also ?

I tried to follow Jackson wiki page article.

EDIT:

On basis of discussion with @Sotirios Delimanolis I tried JsonValue annotation on getter method and it worked.

  @JsonValue
  public String getDateString(){
        return dateString;
  }

Answer 1

Your type is a java.sql.Date which is a java.util.Date which is considered special for Jackson. By default, it writes dates (instances of type java.util.Date ) as their timestamps. You can disable this with

objectMapper.configure(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);

or the corresponding configuration for your version of Jackson.

This, however, will give you something like

"2014-12-08T08:00:00.000+0000"

It will not use your SimpleDateFormat . You can register a DateFormat with the ObjectMapper like so

objectMapper.setDateFormat(new SimpleDateFormat("MM/dd/yyyy"));

---

The best solution would be to use composition over inheritance. Do not extend java.util.Date directly or indirectly.

Answer 2

If you don't want to use a general solution, you can always set format per property

public class DateStuff {
     @JsonFormat(shape=JsonFormat.Shape.STRING, pattern="yyyy-MM-dd,HH:00", timezone="CET")
     public Date creationTime;
}

For more information please read here: http://wiki.fasterxml.com/JacksonFAQDateHandling

Edit:

As a side note

(aka "Please do NOT use java.sql.Date, ever!")

Although Jackson supports java.sql.Date, there are known issues with respect to timezone handling, partly due to design of this class. It is recommended that this type is avoided, if possible, and regular java.util.Date (or java.util.Calendar) used instead. If this is not possible, it may be necessary for applications to convert these dates using java.util.Calendar and explicit timezone definition.