Posted August 5, 2023 by Rohith and Anusha ‐ 3 min read

JSON (JavaScript Object Notation) has become the de facto standard for data interchange between applications. In Java, working with JSON data has traditionally required writing complex and error-prone code. However, with the introduction of Jackson, developers can now process JSON data effortlessly and efficiently.

What is Jackson?

  • Jackson is an open-source Java library for JSON processing.

  • It provides a robust set of features for reading, writing, and manipulating JSON data in Java applications.

  • Developed by FasterXML, Jackson is widely used in various frameworks and projects due to its high performance, flexibility, and ease of use.

Key Features and Functionalities

JSON Serialization and Deserialization

  • Jackson allows developers to convert Java objects to JSON (serialization) and JSON back to Java objects (deserialization).

  • This process is automatic and requires minimal configuration, saving developers from writing boilerplate code.

Streaming API

  • Jackson provides a powerful streaming API for handling large JSON files or when memory efficiency is critical.

  • The streaming API allows processing JSON data incrementally, without loading the entire JSON into memory.

Tree Model

  • Jackson offers a tree model representation of JSON data, which enables developers to work with JSON data using a familiar DOM-like approach.

  • The tree model is useful for scenarios where random access to JSON elements is necessary.

Data Binding

  • Jackson’s data binding functionality maps JSON data to Java objects and vice versa.

  • This process is highly customizable, allowing developers to control how JSON properties are mapped to Java fields.


  • Jackson supports annotations that provide fine-grained control over JSON serialization and deserialization.

  • By adding annotations to Java classes, developers can specify field names, ignore properties, set default values, and more.

Polymorphic Type Handling

  • Jackson allows handling polymorphic types in JSON data, which is particularly useful in cases where the same property can hold different types of objects.

Integration with JAX-RS and Spring

  • Jackson integrates seamlessly with JAX-RS (Java API for RESTful Web Services) and Spring, making it the go-to library for handling JSON data in web services.


Example: JSON Serialization and Deserialization

Let’s see a simple example of how to use Jackson for JSON serialization and deserialization:

import com.fasterxml.jackson.databind.ObjectMapper;

class Person {
    String name;
    int age;

    // Constructors, getters, and setters

public class JacksonExample {
    public static void main(String[] args) throws Exception {
        // Serialization
        ObjectMapper objectMapper = new ObjectMapper();
        Person person = new Person("John Doe", 30);
        String json = objectMapper.writeValueAsString(person);
        System.out.println("Serialized JSON: " + json);

        // Deserialization
        String jsonString = "{\"name\":\"Jane Smith\",\"age\":25}";
        Person deserializedPerson = objectMapper.readValue(jsonString, Person.class);
        System.out.println("Deserialized Person: " + deserializedPerson.getName() + ", " + deserializedPerson.getAge());


  • Jackson has become an essential tool for Java developers working with JSON data.

  • Its straightforward API, high performance, and versatile features make it a top choice for parsing, writing, and manipulating JSON.

  • Whether you are building RESTful web services, processing configuration files, or exchanging data between applications, Jackson simplifies JSON processing, allowing you to focus on building great Java applications.

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