Annotazioni Jackson - Annotazione personalizzata

Possiamo creare facilmente annotazioni personalizzate usando l'annotazione @JacksonAnnotationsInside.

Esempio: annotazione personalizzata

import java.io.IOException;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.text.ParseException;

import com.fasterxml.jackson.annotation.JacksonAnnotationsInside;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonInclude.Include;
import com.fasterxml.jackson.annotation.JsonPropertyOrder;
import com.fasterxml.jackson.databind.ObjectMapper;

public class JacksonTester {
   public static void main(String args[]) throws IOException, ParseException {
      ObjectMapper mapper = new ObjectMapper();     
      Student student = new Student(1,13, "Mark");

      String jsonString = mapper  
         .writerWithDefaultPrettyPrinter()
         .writeValueAsString(student);
      System.out.println(jsonString);
   }
}
@CustomAnnotation
class Student {
   public int id;
   public int rollNo;
   public String name;
   public String otherDetails;

   Student(int id, int rollNo, String name){
      this.id = id;
      this.rollNo = rollNo;
      this.name = name;
   }   
}
@Retention(RetentionPolicy.RUNTIME)
@JacksonAnnotationsInside
@JsonInclude(value = Include.NON_NULL)
@JsonPropertyOrder({ "rollNo", "id", "name" })
@interface CustomAnnotation {}

Produzione

{
   "rollNo" : 13,
   "id" : 1,
   "name" : "Mark"
}