SimpleJson.java

package com.arantaday.json;

import org.codehaus.jackson.map.ObjectMapper;

import java.io.IOException;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;

public class SimpleJson {


  public static enum Department {
    COMPUTER_SCIENCE("CS"),
    ENGLISH("ENG"),
    MATH("MATH");

    private final String shortName;

    private Department(String shortName) {
      this.shortName = shortName;
    }

    public String getShortName() {
      return shortName;
    }
  }

  public static class Course {

    private Department department;
    private String vanityName;
    private long courseNumber;

    public Course() {
    }

    public Course(String vanityName, Department department, long courseNumber) {
      this.vanityName = vanityName;
      this.department = department;
      this.courseNumber = courseNumber;
    }

    public String getVanityName() {
      return vanityName;
    }

    public void setVanityName(String vanityName) {
      this.vanityName = vanityName;
    }

    public long getCourseNumber() {
      return courseNumber;
    }

    public void setCourseNumber(long courseNumber) {
      this.courseNumber = courseNumber;
    }

    public Department getDepartment() {
      return department;
    }

    public void setDepartment(Department department) {
      this.department = department;
    }

    @Override
    public String toString() {
      return "Course{" +
          "department=" + department +
          ", vanityName='" + vanityName + '\'' +
          ", courseNumber=" + courseNumber +
          '}';
    }
  }

  public static class Student {

    private String name;
    private Date dateOfBirth;
    private boolean enrolled;
    private List<Course> courses;

    public Student() {

    }

    public String getName() {
      return name;
    }

    public void setName(String name) {
      this.name = name;
    }

    public Date getDateOfBirth() {
      return dateOfBirth;
    }

    public void setDateOfBirth(Date dateOfBirth) {
      this.dateOfBirth = dateOfBirth;
    }

    public boolean isEnrolled() {
      return enrolled;
    }

    public void setEnrolled(boolean enrolled) {
      this.enrolled = enrolled;
    }

    public List<Course> getCourses() {
      return courses;
    }

    public void setCourses(List<Course> courses) {
      this.courses = courses;
    }

    @Override
    public String toString() {
      return "Student{" +
          "name='" + name + '\'' +
          ", dateOfBirth=" + dateOfBirth +
          ", enrolled=" + enrolled +
          ", courses=" + courses +
          '}';
    }
  }

  private static final ObjectMapper MAPPER = new ObjectMapper();

  public static void main(String[] args) throws IOException {
    // create a student
    final Student student = new Student();
    student.setName("John Doe");
    student.setDateOfBirth(new Date());
    student.setEnrolled(true);
    final List<Course> courses = new LinkedList<Course>();
    courses.add(new Course("Intro to Typing", Department.COMPUTER_SCIENCE, 101));
    courses.add(new Course("Postmodern Deconstructionism", Department.ENGLISH, 201));
    courses.add(new Course("Remedial Galois Field Arithmetic", Department.MATH, 51));
    student.setCourses(courses);

    System.out.printf("The original student object is: '%s'%n", student);

    // serialize the student to a JSON object
    final String serialzed = MAPPER.writeValueAsString(student);
    System.out.printf("The serialized student is: '%s'%n", serialzed);

    // parse the JSON back into a Java object
    final Student deserializedStudent = MAPPER.readValue(serialzed, Student.class);
    System.out.printf("The deserialized student object is: '%s'%n", deserializedStudent);
  }
}