public class Views {
    public static class Public {}
    public static class Internal extends Public {}
}
Можно создавать любые уровни — главное, чтобы они наследовались при необходимости.

import com.fasterxml.jackson.annotation.JsonView;

public class User {
    @JsonView(Views.Public.class)
    private String username;

    @JsonView(Views.Internal.class)
    private String email;

    @JsonView(Views.Internal.class)
    private String role;

    public User() {}

    public User(String username, String email, String role) {
        this.username = username;
        this.email = email;
        this.role = role;
    }

    // Геттеры и сеттеры
}

ObjectMapper mapper = new ObjectMapper();

User user = new User("alice", "alice@example.com", "ADMIN");

// Публичный вид
String publicJson = mapper
    .writerWithView(Views.Public.class)
    .writeValueAsString(user);

System.out.println(publicJson);

{
  "username": "alice"
}

String internalJson = mapper
    .writerWithView(Views.Internal.class)
    .writeValueAsString(user);

{
  "username": "alice",
  "email": "alice@example.com",
  "role": "ADMIN"
}

@GetMapping("/user/public")
@JsonView(Views.Public.class)
public User getPublicUser() {
    return userService.getCurrentUser();
}

@GetMapping("/user/internal")
@JsonView(Views.Internal.class)
public User getInternalUser() {
    return userService.getCurrentUser();
}

public class Task080525 {
    public static void main(String[] args) {
        int count = 0;
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                if (i == j) continue;
                count++;
            }
        }
        System.out.println(count);
    }
}

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

String json = "{ \"user\": { \"name\": \"Alice\", \"age\": 30 } }";

ObjectMapper mapper = new ObjectMapper();
JsonNode rootNode = mapper.readTree(json);

String name = rootNode.path("user").path("name").asText();
int age = rootNode.path("user").path("age").asInt();

System.out.println("Имя: " + name + ", Возраст: " + age);

import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;

JsonFactory factory = new JsonFactory();
JsonParser parser = factory.createParser(new File("data.json"));

while (!parser.isClosed()) {
    JsonToken token = parser.nextToken();

    if (JsonToken.FIELD_NAME.equals(token) && "name".equals(parser.getCurrentName())) {
        parser.nextToken();
        System.out.println("Имя: " + parser.getValueAsString());
    }
}
parser.close();