Spring Boot with H2 Database

Last Updated : 18 Mar, 2025

H2 Database in Spring Boot is an embedded, open-source, and in-memory database. It is a relational database management system written in Java. It is a client/server application. It stores data in memory, not persist the data on disk. Here we will be discussing how can we configure and perform some basic operations in Spring Boot using the H2 Database.

In this article, we will explore how to integrate the H2 Database with Spring Boot. H2 is a lightweight, in-memory database that simplifies development and testing. We'll cover the configuration, key features, and basic CRUD operations to enhance your Spring Boot applications efficiently.

What is H2 Database?

H2 is a lightweight and fast SQL database written in Java. It can run in two modes: in-memory and embedded. The in-memory mode is particularly useful for testing and development because it allows you to create a temporary database that is automatically destroyed when the application stops. The embedded mode is used for applications that need a small, self-contained database.

Features of the H2 Database:

Very fast, open-source, JDBC API
Embedded and server modes; disk-based or in-memory databases.
Transaction support, multi-version concurrency
Browser-based Console application
Encrypted databases
Fulltext search
Pure Java with a small footprint: around 2.5 MB jar file size
ODBC driver

Configure H2 Database in Spring Boot Application

Below are the steps to set up H2 database in Spring Boot application.

Step 1: Adding the dependency

To use the H2 database in the spring boot application we have to add the following dependency in the pom.xml file:

h2 and spring-boot-starter-data-jpa dependencies:

<dependency>
      <groupId>org.springframework.boot</groupId>       
      <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
      <groupId>com.h2database</groupId>
      <artifactId>h2</artifactId>
      <scope>runtime</scope>
 </dependency>

Step 2: Configure Application Properties

Configure the H2 database in the application.properties file:

# H2 Database
spring.h2.console.enabled=true
spring.datasource.url=jdbc:h2:mem:dcbapp
spring.datasource.driver-class-name=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=password
spring.jpa.database-platform=org.hibernate.dialect.H2Dialect

We can also use YAML file for database configuration by adding properties to application.yml file as depicted below:

spring:
    h2:
         console.enabled: true
    datasource:
         url: jdbc:h2:mem:dcbapp
         driver-class-name: org.h2.Driver
         username: sa
         password: password
     jpa: 
         spring.jpa.database-platform: org.hibernate.dialect.H2Dialect

Let's understand what these properties are by opening the H2 Database console.

Accessing the H2 Console

By default, the console view of the H2 database is disabled. Before accessing the H2 database, we must enable it by using the following property:

spring.h2.console.enabled=true

Once we have enabled the H2 console, now we can access the H2 console in the browser by invoking the URL http://localhost:8082/h2-console .

Note : Provide your port number in which your spring application is running

The following figure shows the console view of the H2 database.

Using H2 Database to perform CRUD Operation in Spring Boot

We are going to perform some basic CRUD Operations by creating a Spring Boot Application and using the H2 Database.

Step 1: Create a Spring Boot Project

Refer to this article How to Create a Spring Boot Project with IntelliJ IDEA and create a Spring Boot project.

Step 2: Add the following dependency

Spring Web
H2 Database
Lombok
Spring Data JPA

Below is the complete code for the pom.xml file. Please check if you have missed something.

pom.xml:

XML

<?xml version="1.0" encoding="UTF-8"?>  <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">     <modelVersion>4.0.0</modelVersion>     <parent>         <groupId>org.springframework.boot</groupId>         <artifactId>spring-boot-starter-parent</artifactId>         <version>2.5.5</version>         <relativePath/> <!-- lookup parent from repository -->     </parent>     <groupId>com.amiya</groupId>     <artifactId>Spring-Boot-Demo-Project</artifactId>     <version>1.0.0-SNAPSHOT</version>     <name>Spring-Boot-Demo-Project</name>     <description>Demo project for Spring Boot</description>     <properties>         <java.version>11</java.version>     </properties>     <dependencies>         <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-web</artifactId>         </dependency>          <dependency>             <groupId>com.h2database</groupId>             <artifactId>h2</artifactId>             <scope>runtime</scope>         </dependency>          <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-devtools</artifactId>             <scope>runtime</scope>             <optional>true</optional>         </dependency>          <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-data-jpa</artifactId>         </dependency>          <dependency>             <groupId>org.springframework.boot</groupId>             <artifactId>spring-boot-starter-test</artifactId>             <scope>test</scope>         </dependency>          <dependency>             <groupId>org.projectlombok</groupId>             <artifactId>lombok</artifactId>             <optional>true</optional>         </dependency>      </dependencies>      <build>         <plugins>             <plugin>                 <groupId>org.springframework.boot</groupId>                 <artifactId>spring-boot-maven-plugin</artifactId>                 <configuration>                     <excludes>                         <exclude>                             <groupId>org.projectlombok</groupId>                             <artifactId>lombok</artifactId>                         </exclude>                     </excludes>                 </configuration>             </plugin>         </plugins>     </build>  </project>

Step 3: Create Classes

Create 4 packages and later create some classes and interfaces inside these packages as seen in the below image

entity
repository
service
controller

Note:
Green Rounded Icon 'I' Buttons are Interface.
Blue Rounded Icon 'C' Buttons are Classes.

Step 4: Entity Class

Create a simple POJO class inside the Department.java file.

Department.java:

Java

// Java Program to Demonstrate Department File  // Importing required package modules package com.amiya.springbootdemoproject.entity;  // Importing required classes (using jakarta.persistence now) import jakarta.persistence.Entity; import jakarta.persistence.GeneratedValue; import jakarta.persistence.GenerationType; import jakarta.persistence.Id; import lombok.AllArgsConstructor; import lombok.Builder; import lombok.Data; import lombok.NoArgsConstructor;  @Entity @Data @NoArgsConstructor @AllArgsConstructor @Builder  // Class public class Department {      @Id     @GeneratedValue(strategy = GenerationType.AUTO)     private Long departmentId;     private String departmentName;     private String departmentAddress;     private String departmentCode; }

Step 5: Create Repository

Create a simple interface and name the interface as DepartmentRepository. This interface is going to extend the CrudRepository as we have discussed above.

Example: Below is the code for the DepartmentRepository.java file.

Java

package com.amiya.springbootdemoproject.repository;  import com.amiya.springbootdemoproject.entity.Department; import org.springframework.data.repository.CrudRepository; import org.springframework.stereotype.Repository;  // Annotation @Repository  // Interface extending CrudRepository public interface DepartmentRepository     extends CrudRepository<Department, Long> { }

Step 6: Create a Service Class

Inside the package create one interface named as DepartmentService and one class named as DepartmentServiceImpl.

Example 1-A:

Java

// Java Program to Demonstrate DepartmentService File  // Importing required package modules package com.amiya.springbootdemoproject.service; import com.amiya.springbootdemoproject.entity.Department; // Importing required classes import java.util.List;  // Interface public interface DepartmentService {      // Save operation     Department saveDepartment(Department department);      // Read operation     List<Department> fetchDepartmentList();      // Update operation     Department updateDepartment(Department department,                                 Long departmentId);      // Delete operation     void deleteDepartmentById(Long departmentId); }

Example 1-B:

Java

// Java Program to Demonstrate DepartmentServiceImpl.java // File  // Importing required package modules package com.amiya.springbootdemoproject.service;  import com.amiya.springbootdemoproject.entity.Department; import com.amiya.springbootdemoproject.repository.DepartmentRepository; import java.util.List; import java.util.Objects; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service;  // Annotation @Service  // Class public class DepartmentServiceImpl     implements DepartmentService {      @Autowired     private DepartmentRepository departmentRepository;      // Save operation     @Override     public Department saveDepartment(Department department)     {         return departmentRepository.save(department);     }      // Read operation     @Override public List<Department> fetchDepartmentList()     {         return (List<Department>)             departmentRepository.findAll();     }      // Update operation     @Override     public Department     updateDepartment(Department department,                      Long departmentId)     {         Department depDB             = departmentRepository.findById(departmentId)                   .get();          if (Objects.nonNull(department.getDepartmentName())             && !"".equalsIgnoreCase(                 department.getDepartmentName())) {             depDB.setDepartmentName(                 department.getDepartmentName());         }          if (Objects.nonNull(                 department.getDepartmentAddress())             && !"".equalsIgnoreCase(                 department.getDepartmentAddress())) {             depDB.setDepartmentAddress(                 department.getDepartmentAddress());         }          if (Objects.nonNull(department.getDepartmentCode())             && !"".equalsIgnoreCase(                 department.getDepartmentCode())) {             depDB.setDepartmentCode(                 department.getDepartmentCode());         }          return departmentRepository.save(depDB);     }      // Delete operation     @Override     public void deleteDepartmentById(Long departmentId)     {         departmentRepository.deleteById(departmentId);     } }

Step 7: Create Controller

Inside the package create one class named as DepartmentController.

Java

// java Program to Illustrate DepartmentController File  // Importing required packages modules package com.amiya.springbootdemoproject.controller;  import com.amiya.springbootdemoproject.entity.Department; import com.amiya.springbootdemoproject.service.DepartmentService; import java.util.List; // Importing required classes import jakarta.validation.Valid; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.web.bind.annotation.*;  // Annotation @RestController  // Class public class DepartmentController {      @Autowired private DepartmentService departmentService;      // Save operation     @PostMapping("/departments")     public Department saveDepartment(         @Valid @RequestBody Department department)     {         return departmentService.saveDepartment(department);     }      // Read operation     @GetMapping("/departments")     public List<Department> fetchDepartmentList()     {         return departmentService.fetchDepartmentList();     }      // Update operation     @PutMapping("/departments/{id}")     public Department     updateDepartment(@RequestBody Department department,                      @PathVariable("id") Long departmentId)     {         return departmentService.updateDepartment(             department, departmentId);     }      // Delete operation     @DeleteMapping("/departments/{id}")     public String deleteDepartmentById(@PathVariable("id")                                        Long departmentId)     {         departmentService.deleteDepartmentById(             departmentId);         return "Deleted Successfully";     } }

Accessing H2 Database

Below are the properties for the application.properties file.

server.port = 8082

# H2 Database
spring.h2.console.enabled=true
spring.datasource.url=jdbc:h2:mem:dcbapp
spring.datasource.driverClassName=org.h2.Driver
spring.datasource.username=sa
spring.datasource.password=password
spring.jpa.database-platform=org.hibernate.dialect.H2Dialect

For application.yml file:

spring:
    h2:
        console.enabled=true
    datasource:
        url: jdbc:h2:mem:dcbapp
        driverClassName: org.h2.Driver
        username: sa
        password: password
    jpa:
        spring.jpa.database-platform: org.hibernate.dialect.H2Dialect

Now run your application and let's test the endpoints in Postman and also refer to our H2 Database.