Jackson Annotations - @JsonFilter

Overview

@JsonIdentityInfo is used to apply filter during serialization/de-serialization like which properties are to be used or not.

Usage of @JsonFilter

Annotate Class with @JsonFilter

@JsonFilter("nameFilter")
class Student {
   public int id;
   ...
}

Create a Filter

FilterProvider filters = new SimpleFilterProvider() .addFilter(
   "nameFilter", SimpleBeanPropertyFilter.filterOutAllExcept("name"));

Apply the Filter

String jsonString = mapper.writer(filters)             
   .withDefaultPrettyPrinter()
   .writeValueAsString(student);

Example - Serialization with @JsonFilter

JacksonTester.java

package com.tutorialspoint;

import java.io.IOException;
import java.text.ParseException;

import com.fasterxml.jackson.annotation.JsonFilter;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.ser.FilterProvider;
import com.fasterxml.jackson.databind.ser.impl.SimpleBeanPropertyFilter;
import com.fasterxml.jackson.databind.ser.impl.SimpleFilterProvider;

public class JacksonTester {
   public static void main(String args[]) throws IOException, ParseException {
      ObjectMapper mapper = new ObjectMapper();     
      Student student = new Student(1,13, "Mark");
      
      FilterProvider filters = new SimpleFilterProvider() .addFilter(
         "nameFilter", SimpleBeanPropertyFilter.filterOutAllExcept("name"));
      
      String jsonString = mapper.writer(filters)             
         .withDefaultPrettyPrinter()
         .writeValueAsString(student);
      System.out.println(jsonString);
   }
}
@JsonFilter("nameFilter")
class Student {
   public int id;
   public int rollNo;
   public String name;

   Student(int id, int rollNo, String name) {
      this.id = id;
      this.rollNo = rollNo;
      this.name = name;
   }   
}

Output

Run the JacksonTester and verify the output −

{
  "name" : "Mark"
}

Here we can see, using JsonFilter we're able to filter object properties.