Json Library Java May 2026

User user = gson.fromJson(json, User.class);

// Deserialize User result = jsonb.fromJson(json, User.class); | Library | Serialization Speed | Deserialization Speed | Memory Usage | |---------|--------------------|----------------------|---------------| | Jackson | Fastest | Fastest | Moderate | | Gson | Fast | Fast | Low | | JSON-java | Slow | Slow | High (creates many objects) | | JSON-B (Yasson) | Moderate | Moderate | Moderate |

@JsonIgnoreProperties(ignoreUnknown = true) public class User // ... json library java

Whichever library you choose, mastering JSON processing is essential for modern Java development. Now go convert those objects to JSON and back! Did I miss your favorite library? Let me know about JSON-smart, Moshi (from Square), or Boon in the comments below!

String json = "\"name\":\"Bob\",\"age\":25"; User user = mapper.readValue(json, User.class); System.out.println(user.getName()); // Bob User user = gson

ObjectMapper mapper = new ObjectMapper(); User user = new User("Alice", 30); String json = mapper.writeValueAsString(user); System.out.println(json); // Output: "name":"Alice","age":30

import com.fasterxml.jackson.databind.ObjectMapper; public class User private String name; private int age; // constructors, getters, setters... Did I miss your favorite library

System.out.println(obj.toString(2)); // pretty print with 2 spaces indent