Jackson @JsonPropertyOrder Example

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Jackson library provides a @JsonPropertyOrder annotation to specify the order of properties on serialization.

Dependencies

Let’s first add the following dependencies to the pom.xml:
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.9.8</version>
</dependency>
This dependency will also transitively add the following libraries to the classpath:
  • jackson-annotations-2.9.8.jar
  • jackson-core-2.9.8.jar
  • jackson-databind-2.9.8.jar
Always use the latest versions on the Maven central repository for Jackson databind.

Jackson @JsonPropertyOrder Example

Let’s set a custom order for the properties of a User entity:

User.java

package net.javaguides.jackson.annotations;

import com.fasterxml.jackson.annotation.JsonPropertyOrder;

@JsonPropertyOrder({
    "fullName",
    "id",
    "firstName",
    "lastName"
})
public class User {

    public int id;

    private String firstName;

    private String lastName;

    private String fullName;

    public User(int id, String firstName, String lastName, String fullName) {
        super();
        this.id = id;
        this.firstName = firstName;
        this.lastName = lastName;
        this.fullName = fullName;
    }

    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getFirstName() {
        return firstName;
    }
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }
    public String getLastName() {
        return lastName;
    }
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
    public String getFullName() {
        return fullName;
    }
    public void setFullName(String fullName) {
        this.fullName = fullName;
    }
}
Let's test usage of @JsonPropertyOrder annotation using a main() method.

JacksonPropertyOrderDemo.java

package net.javaguides.jackson.annotations;

import java.io.IOException;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;

public class JacksonPropertyOrderDemo{
 public static void main(String[] args) throws IOException {

  // Create ObjectMapper object.
  ObjectMapper mapper = new ObjectMapper();
  mapper.enable(SerializationFeature.INDENT_OUTPUT);
  User bean = new User(1, "Ramesh", "Fadatare", "Ramesh Fadatare");
  String result = mapper.writeValueAsString(bean);

  System.out.println(result);
 }
}
Output:
{
  "fullName" : "Ramesh Fadatare",
  "id" : 1,
  "firstName" : "Ramesh",
  "lastName" : "Fadatare"
}

Order the Properties Alphabetically

We can also use @JsonPropertyOrder(alphabetic=true) to order the properties alphabetically.
@JsonPropertyOrder(alphabetic=true)
public class User {
 
    private int id;
 
    private String firstName;
 
    private String lastName;
    
    private String fullName;
And in that case the output of serialization will be:
{
  "firstName" : "Ramesh",
  "fullName" : "Ramesh Fadatare",
  "id" : 1,
  "lastName" : "Fadatare"
}



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