In Java, how can we map multiple date formats using Jackson?

Jackson is a Java-based library that is useful for converting Java objects to JSON and JSON to Java objects. We can map multiple date formats in the Jackson library using the @JsonFormat annotation, which is a generic annotation used to configure the details of how a property value is serialized. @JsonFormat has three important fields: shape, mode and timezone. shape fields can define structures used for serialization (JsonFormat.Shape.NUMBER and JsonFormat.Shape.STRING), mode fields Can be used for serialization and deserialization. For dates, the schema contains SimpleDateFormat compatible definitions, and finally, the timezone field is available for serialization and defaults to the system default time zone.

Grammar

@Target(value={ANNOTATION_TYPE,FIELD,METHOD,PARAMETER,TYPE})
@Retention(value=RUNTIME)
public @interface JsonFormat<strong>
</strong>

Example

Chinese translation is:

Example

import java.io.*;
import java.util.Date;
import com.fasterxml.jackson.annotation.JsonFormat;
import com.fasterxml.jackson.databind.ObjectMapper;
public class JacksonDateformatTest {
   final static ObjectMapper mapper = new ObjectMapper();
   public static void main(String[] args) throws Exception {
      JacksonDateformatTest jacksonDateformat = new JacksonDateformatTest();
      jacksonDateformat.dateformat();
   }
   public void dateformat() throws Exception {
      String json = "{\"createDate\":\"1980-12-08\"," + "\"createDateGmt\":\"1980-12-08 3:00 PM GMT+1:00\"}";
      Reader reader = new StringReader(json);
      Employee employee = mapper.<strong>readValue</strong>(reader, <strong>Employee.class</strong>);
      System.out.println(employee);
   }
}
// Employee class
class Employee implements Serializable {
   @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd", timezone = "IST")
   private Date createDate;
   @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd HH:mm a z", timezone = "IST")<strong>
</strong>   private Date createDateGmt;
   public Date getCreateDate() {
      return createDate;
   }
   public void setCreateDate(Date createDate) {
      this.createDate = createDate;
   }
   public Date getCreateDateGmt() {
      return createDateGmt;
   }
   public void setCreateDateGmt(Date createDateGmt) {
      this.createDateGmt = createDateGmt;
   }
<strong>  </strong> @Override
   public String toString() {
      return "Employee [\ncreateDate=" + createDate + ", \ncreateDateGmt=" + createDateGmt + "\n]";
   }
}

Output

Employee [
 createDate=Mon Dec 08 00:00:00 IST 1980,
 createDateGmt=Mon Dec 08 07:30:00 IST 1980
]

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