Cómo convertir JSON a un objeto Java

Si necesita convertir JSON en un objeto Java, puede realizar una de las siguientes acciones:

Opción 1 – Usar Gson

import com.google.gson.Gson;

public class SimpleTesting {
    public static void primary(String() args) throws InterruptedException {
        String json = """
            {
                "firstName" : "Jane",
                "lastName" : "Doe",
                "dateOfBirth" : "1973-04-29",
                "handle" : "81 Hype",
                "metropolis" : "New York",
                "contact" : "0123456789"
            }
            """;
        Pupil knowledge = new Gson().fromJson(json, Pupil.class);

        System.out.println(knowledge.getFirstName());
        System.out.println(knowledge.getLastName());
        System.out.println(knowledge.getCity());
    }
}

class Pupil {
    non-public String firstName;
    non-public String lastName;
    non-public String dateOfBirth;
    non-public String handle;
    non-public String metropolis;
    non-public String contact;

    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 getDateOfBirth() {
        return dateOfBirth;
    }
    public void setDateOfBirth(String dateOfBirth) {
        this.dateOfBirth = dateOfBirth;
    }
    public String getAddress() {
        return handle;
    }
    public void setAddress(String handle) {
        this.handle = handle;
    }
    public String getCity() {
        return metropolis;
    }
    public void setCity(String metropolis) {
        this.metropolis = metropolis;
    }
    public String getContact() {
        return contact;
    }
    public void setContact(String contact) {
        this.contact = contact;
    }
}

Opción 2 – Usar Jackson

import java.io.File;
import java.io.IOException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;

public class SimpleTesting {
    public static void primary(String() args) throws InterruptedException {
        ObjectMapper mapper = new ObjectMapper();
        mapper.allow(SerializationFeature.INDENT_OUTPUT);
        attempt {
            Pupil scholar = mapper.readValue(new File("json-file.json"), Pupil.class);

            System.out.println("First Title: "+scholar.getFirstName());
            System.out.println("Final Title: "+scholar.getLastName());
            System.out.println("Metropolis: "+scholar.getCity());
            System.out.println("Handle: "+scholar.getAddress());
            System.out.println("Contact: "+scholar.getContact());
            System.out.println("Date of Start: "+scholar.getDateOfBirth());
        } catch(IOException e) {
            e.printStackTrace();
        }
    }
}

class Pupil {
    non-public String firstName;
    non-public String lastName;
    non-public String dateOfBirth;
    non-public String handle;
    non-public String metropolis;
    non-public String contact;

    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 getDateOfBirth() {
        return dateOfBirth;
    }
    public void setDateOfBirth(String dateOfBirth) {
        this.dateOfBirth = dateOfBirth;
    }
    public String getAddress() {
        return handle;
    }
    public void setAddress(String handle) {
        this.handle = handle;
    }
    public String getCity() {
        return metropolis;
    }
    public void setCity(String metropolis) {
        this.metropolis = metropolis;
    }
    public String getContact() {
        return contact;
    }
    public void setContact(String contact) {
        this.contact = contact;
    }
}