Spring Boot with H2 Database


In this quick tutorial, we’ll bootstrap a simple Spring Boot application backed by an in-memory H2 database. We’ll use the Spring Data JPA to interact with our database.

Project Setup:

Firstly, let’s generate our project template using Spring Initializr:

Spring Initalizr

On clicking the ‘Generate the project’ link, our project files will get downloaded.

Now, if we look closely at the generated POM file, we’ll have below added dependencies:


H2 Default Properties:

Since we have added H2 database dependency, Spring Boot will auto-configure its related properties. The default configurations include:


Let’s override a few of these properties by defining those in our application.properties file:


Here, our database name will be a university. We have also enabled the H2 Console and have set its context path.

Defining Entities:

Now, we’ll define a Student entity:

public class Student {
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;

    private String name;
    public Student(String name) {
        this.name = name;   
    //getters, setters

    public String toString() {
        return "{id=" + id + ", name=" + name + "}";

And its corresponding Spring Data JPA repository:

public interface StudentRepository
  extends CrudRepository<Student, Integer> {

The Student entity will get mapped to the database table with exactly the same name. If we want, we can specify a different table name with @Table annotation.

The Application Class:

Finally, let’s implement our UniversityApplication class:

public class UniversityApplication {

    public static void main(String[] args) {
        SpringApplication.run(UniversityApplication.class, args);      

    public CommandLineRunner testApp(StudentRepository repo) {
        return args -> {
            repo.save(new Student("James"));
            repo.save(new Student("Selena"));

            List<Student> allStudents = repo.findAll();
            System.out.println("All students in DB: " + allStudents);

            Student james = repo.findById(1);
            System.out.println("James: " + james);

This class is the starting point for our Spring Boot application. Here, the @SpringBootApplication annotation is equivalent to having @ComponentScan, @EnableAutoConfiguration, and @SpringConfiguration together.

We have also defined an instance of CommandLineRunner. And so, when we run our application, our console logs will have:

UniversityApplication:All students in DB: [{id=1, name=James}
 , {id=2, name=Selena}]
James: {id=1, name=James}

Please note that in Spring Boot, all entities should ideally be defined at either the same package level or at lower levels(in sub-packages) to that of the main application class. If so, Spring Boot will auto-scan all those entities.

Accessing the H2 Console:

We can also check the database entries on the H2 console.

To do that, we’ll open the URL: http://localhost:8080/h2 on any browser and use our database configurations to login. With it, we’ll be able to see all our created tables and entries easily on a UI Console dashboard.


In this tutorial, we bootstrapped a very simple Spring Boot application with a single entity. This application is integrated with the H2 database and uses Spring Data JPA.
We can easily extend it to cater to a much wider application scope.

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