Environment variables are a common way to configure applications across different environments (development, testing, production, etc.). Spring Boot provides multiple ways to use environment variables in its configuration files. In this tutorial, we'll explore how to use environment variables in Spring Boot's properties files.
Prerequisites
- JDK 17 or later
- Maven or Gradle
- IDE (IntelliJ IDEA, Eclipse, etc.)
Step 1: Set Up a Spring Boot Project
1.1 Create a New Spring Boot Project
Use Spring Initializr to create a new project with the following dependencies:
- Spring Web
- Spring Boot Actuator
Download and unzip the project, then open it in your IDE.
Step 2: Configuring Properties Files with Environment Variables
Spring Boot allows you to reference environment variables in your application.properties
or application.yml
files using the ${...}
syntax.
2.1 Using Environment Variables in application.properties
You can refer to environment variables in the application.properties
file using the ${...}
syntax. For example, if you want to configure your database connection using environment variables, you can do it as follows:
# application.properties
spring.datasource.url=${DB_URL}
spring.datasource.username=${DB_USERNAME}
spring.datasource.password=${DB_PASSWORD}
spring.datasource.driver-class-name=${DB_DRIVER:org.h2.Driver}
Explanation:
${DB_URL}
: Refers to the DB_URL
environment variable.
${DB_USERNAME}
: Refers to the DB_USERNAME
environment variable.
${DB_PASSWORD}
: Refers to the DB_PASSWORD
environment variable.
${DB_DRIVER:org.h2.Driver}
: Refers to the DB_DRIVER
environment variable and defaults to org.h2.Driver
if the environment variable is not set.
2.2 Using Environment Variables in application.yml
Similarly, you can use environment variables in the application.yml
file:
# application.yml
spring:
datasource:
url: ${DB_URL}
username: ${DB_USERNAME}
password: ${DB_PASSWORD}
driver-class-name: ${DB_DRIVER:org.h2.Driver}
2.3 Setting Environment Variables
2.3.1 Setting Environment Variables in the Shell
You can set environment variables in your shell before running the Spring Boot application:
export DB_URL=jdbc:mysql://localhost:3306/mydb
export DB_USERNAME=root
export DB_PASSWORD=secret
export DB_DRIVER=com.mysql.cj.jdbc.Driver
./mvnw spring-boot:run
2.3.2 Setting Environment Variables in an IDE
Most IDEs allow you to set environment variables for your application. For example, in IntelliJ IDEA:
- Open the Run/Debug Configurations dialog.
- Select your application.
- Add the environment variables in the Environment Variables field (e.g.,
DB_URL=jdbc:mysql://localhost:3306/mydb;DB_USERNAME=root;DB_PASSWORD=secret;DB_DRIVER=com.mysql.cj.jdbc.Driver
).
2.4 Accessing Environment Variables Programmatically
You can also access environment variables programmatically in your Spring Boot application using the @Value
annotation or the Environment
abstraction.
2.4.1 Using @Value
Annotation
package com.example.demo;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
@Component
public class MyComponent {
@Value("${DB_URL}")
private String dbUrl;
@Value("${DB_USERNAME}")
private String dbUsername;
@Value("${DB_PASSWORD}")
private String dbPassword;
@Value("${DB_DRIVER:org.h2.Driver}")
private String dbDriver;
// Getters and other methods
}
2.4.2 Using Environment
Abstraction
package com.example.demo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.env.Environment;
import org.springframework.stereotype.Component;
@Component
public class MyComponent {
@Autowired
private Environment env;
public void printDatabaseConfig() {
String dbUrl = env.getProperty("DB_URL");
String dbUsername = env.getProperty("DB_USERNAME");
String dbPassword = env.getProperty("DB_PASSWORD");
String dbDriver = env.getProperty("DB_DRIVER", "org.h2.Driver");
System.out.println("Database URL: " + dbUrl);
System.out.println("Database Username: " + dbUsername);
System.out.println("Database Password: " + dbPassword);
System.out.println("Database Driver: " + dbDriver);
}
}
Step 3: Example REST Controller
Create a REST controller to demonstrate the use of environment variables.
package com.example.demo.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.env.Environment;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class ConfigController {
@Autowired
private Environment env;
@GetMapping("/config")
public String getConfig() {
String dbUrl = env.getProperty("DB_URL");
String dbUsername = env.getProperty("DB_USERNAME");
String dbPassword = env.getProperty("DB_PASSWORD");
String dbDriver = env.getProperty("DB_DRIVER", "org.h2.Driver");
return "Database URL: " + dbUrl + "\n"
+ "Database Username: " + dbUsername + "\n"
+ "Database Password: " + dbPassword + "\n"
+ "Database Driver: " + dbDriver;
}
}
Step 4: Running the Application
4.1 Setting Environment Variables and Running
Set the environment variables in your shell and run the application:
export DB_URL=jdbc:mysql://localhost:3306/mydb
export DB_USERNAME=root
export DB_PASSWORD=secret
export DB_DRIVER=com.mysql.cj.jdbc.Driver
./mvnw spring-boot:run
4.2 Testing the Configuration
Open your browser and navigate to http://localhost:8080/config
to see the configuration values retrieved from the environment variables.
Conclusion
In this tutorial, you have learned how to use environment variables in Spring Boot's properties files. This approach provides a flexible and secure way to configure your application across different environments. You also learned how to set environment variables in the shell and IDE, and how to access these variables programmatically in your Spring Boot application.
Related Spring Boot Source Code Examples
Spring Boot Security Login REST API Example
Spring Boot Security Login and Registration REST API
Role-based Authorization using Spring Boot and Spring Security
Spring Boot JWT Authentication and Authorization Example
Spring Boot Security JWT Example - Login REST API with JWT Authentication
Spring Boot DTO Example
Spring Boot DTO ModelMapper Example
@GetMapping Spring Boot Example
@PostMapping Spring Boot Example
@PutMapping Spring Boot Example
@DeleteMapping Spring Boot Example
@PatchMapping Spring Boot Example
@SpringBootApplication - Spring Boot
Spring Boot Hello World REST API Example
Spring Boot REST API returns Java Bean
Create Spring Boot REST API returns List
Spring Boot REST API with Path Variable
Spring Boot REST API with Request Param
Spring Boot Hibernate MySQL CRUD REST API Tutorial
Spring Boot Real-Time Project Development using Spring MVC + Spring Security + Thymeleaf and MySQL Database
Spring Boot Tutorial - User Login and Registration Backend + Email Verification
Spring Boot JUnit and Mockito Example - Service Layer Testing
Spring Professional Certification Cost
Spring Boot Validate JSON Request Body
Spring Boot One to Many CRUD Example | REST Controller
Spring Boot Project with Controller Layer + Service Layer + Repository/DAO Layer
Spring Boot Reactive MongoDB CRUD Example - WebFlux
Spring Boot Amazon S3 - File Upload Download Delete Example
Spring Boot RabbitMQ Publisher and Consumer Example
Free Spring Boot Open Source Projects for Learning Purposes
Spring Boot + Microsoft SQL Server + Hibernate Example
Spring Boot Hibernate Thymeleaf MySQL CRUD Example
Spring Boot CRUD Example with Spring MVC, Spring Data JPA, ThymeLeaf, Hibernate, MySQL
Spring Boot Hibernate RESTful GET POST PUT and DELETE API Tutorial
Best YouTube Channels to learn Spring Boot
React Spring Boot Example
Spring Boot Groovy Thymeleaf Example Tutorial
Spring Boot Scala Thymeleaf Example Tutorial
Spring Boot Hibernate DAO with MySQL Database Example
Spring Boot PostgreSQL CRUD Example
Spring Boot CRUD Example with MySQL
Spring Boot Starter Parent
Spring Boot JdbcTemplate Example
Spring Boot PayPal Payment Gateway Integration Example
Create Spring Boot REST API
How to Create Spring Boot Application Using Maven
How to Create Spring Boot Application Using Gradle
How to Use Thymeleaf in a Spring Boot Web Application?
How to Enable CORS in a Spring Boot Application?
Spring Boot + Angular 8 CRUD Example
Spring Boot + Angular 9 CRUD Example
Spring Boot + Angular + WebSocket Example
Spring Boot CRUD Application with Thymeleaf
Spring Boot ReactJS CRUD Project - Employee Management App | GitHub
Spring Petclinic ReactJS Project | GitHub
Spring Boot React JWT Authentication Example
Spring Boot React Basic Authentication Example
CRUD Example using Spring Boot + Angular + MySQL
Spring Boot + React + Redux CRUD Example
Spring Boot Project - Sagan
Spring Boot Project - ReactJS Spring Boot CRUD Full Stack Application - GitHub
Spring Boot Project - Spring Initializr
Spring Boot + Angular Project - Employee Management System
Spring Boot Thymeleaf Project - Employee Management System
Spring Boot MVC Project - Blogs Aggregator
Spring Boot Project - Spring Petclinic | GitHub
Spring Boot, Spring Cloud Microservice Project - PiggyMetrics | GitHub
Spring Boot, Spring Security, JWT, React, and Ant Design - Polling App | GitHub
Spring Boot Microservice Project - Shopping Cart App | GitHub
Spring Boot, Spring Cloud Microservice Project - Spring Petclinic App | GitHub
Microservices with Spring Cloud Project | GitHub
Spring Boot Angular Petclinic Project | GitHub
Spring Boot Angular Project - BookStore App | GitHub
React Springboot Microservices Project | GitHub
Spring Boot Microservices, Spring Cloud, and React Project - BookStoreApp | GitHub
Spring Boot + Spring Security + JWT Example
Spring Boot Hibernate Assign UUID Identifiers Example
Spring Boot Angular Project - Reddit Clone Application
Spring Boot Step-by-Step Example
Spring Boot Starters List
Spring Boot E-Commerce Project - Shopizer
Spring Data JPA - save() Method Example
Spring Data JPA - saveAll() Method Example
Spring Data JPA - findById() Method Example
Spring Data JPA - findAll() Method Example
Spring Data JPA - count() Method Example
Spring Data JPA - deleteById() Method Example
Spring Data JPA - delete() Method Example
Spring Data JPA - deleteAll() Method Example
Spring Data JPA - Distinct Query Method Example
Spring Data JPA - GreaterThan Query Method Example
Spring Data JPA - LessThan Query Method Example
Spring Data JPA - Containing Query Method Example
Spring Data JPA - Like Query Method Example
Spring Data JPA - Between Query Method Example
Spring Data JPA - Date Range Between Query Method Example
Spring Data JPA - In Clause Query Method Example
Unit Test Spring Boot GET REST API using JUnit and Mockito
Unit Test Spring Boot POST REST API using JUnit and Mockito
Unit Test Spring Boot PUT REST API using JUnit and Mockito
Unit Test Spring Boot DELETE REST API using JUnit and Mockito
Create REST Client using WebClient for Spring Boot CRUD REST API
Spring Boot WebClient GET Request with Parameters
Spring Boot WebClient POST Request Example
Spring Boot WebClient PUT Request Example
Spring Boot WebClient DELETE Request Example
Spring Boot RestClient GET Request Example
Spring Boot RestClient POST Request Example
Spring Boot RestClient PUT Request Example
Spring Boot RestClient Delete Request Example
Spring Core Annotations with Examples
Spring Boot @Component Example
Spring Boot @Autowired Example
Spring Boot @Qualifier Example
Spring Boot @Primary Example
Spring Boot @Bean Example
Spring Boot @Lazy Example
Spring Boot @Scope Example
Spring Boot @PropertySource Example
Spring Boot @Transactional Example
Spring Boot @Configuration Example
Spring Boot @ComponentScan Example
Spring Boot @Profile Example
Spring Boot @Cacheable Example
Spring Boot @DependsOn Example
Spring Boot @RestController Example
Spring Boot @ResponseBody Example
Spring Boot @GetMapping Example
Spring Boot @PostMapping Example
Spring Boot @PutMapping Example
Spring Boot @DeleteMapping Example
Spring Boot @PatchMapping Example
Spring Boot @PathVariable Example
Spring Boot @ResponseStatus Example
Spring Boot @Service Example
Spring Boot @Repository Example
Spring Boot @RequestParam Example
Spring Boot @SessionAttribute Example
Spring Boot @RequestBody Example
Spring Boot @ExceptionHandler Example
Spring Boot @InitBinder Example
Spring Boot @ModelAttribute Example
Spring Boot @RequestMapping Example
Spring Boot @CrossOrigin Example
Spring Boot @ControllerAdvice Example
Spring Boot @RestControllerAdvice Example
Spring Boot @SpringBootApplication Example
Spring Boot @EnableAutoConfiguration Example
Spring Boot @ConditionalOnClass Example
Spring Boot @SpringBootConfiguration Example
Spring Boot @ConditionalOnProperty Example
Spring Boot @ConditionalOnWebApplication Example
Spring Boot @ConfigurationProperties Example
Spring Boot @Async Example
Spring Boot @Scheduled Example
Spring Boot @SpringBootTest Example
Spring Boot @WebMvcTest Example
Spring Boot @DataJpaTest Example
Spring Boot @EnableDiscoveryClient Example
Spring Boot @EnableFeignClients Example
Spring Boot @RefreshScope Example
Spring Boot @LoadBalanced Example
Spring Boot @Query Example
Spring Boot @Modifying Example
Spring Boot @Param Example
Spring Boot JPA @Transient Example
Spring Boot JPA @Enumerated Example
Spring Boot JPA @Temporal Example
Spring Boot @CreatedBy Example
Spring Boot @LastModifiedDate Example
Spring Boot @IdClass Example
Spring Boot
Comments
Post a Comment