Introduction to Jackson
Java requires a third-party library to process JSON, and Jackson is a popular choice:
💡 Maven Dependency:
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.15.2</version>
</dependency>Basic Usage
Object to JSON
ObjectMapper mapper = new ObjectMapper();
User user = new User("John Doe", 30);
String json = mapper.writeValueAsString(user);
// {"name":"John Doe","age":30}JSON to Object
String json = "{\"name\":\"Jane Smith\",\"age\":28}";
User user = mapper.readValue(json, User.class);
System.out.println(user.getName());
// Jane Smith
🛠️
Productivity Booster
Not sure if the backend API JSON structure is correct? Don't just rely on logs, verify it with a tool for peace of mind.
👉 Online JSON ValidatorSpring Boot Automatic Conversion
Spring Boot automatically handles JSON conversion:
@RestController
public class UserController {
@GetMapping("/users")
public List getUsers() {
return Arrays.asList(
new User("John Doe", 30),
new User("Jane Smith", 28)
);
}
}