Spring wont read .env

Question

My app wont get data from .env file. I have set

spring.config.import=optional:file:.env[.properties] 

in my application.properties. If i change this, it will immediately say file does not exist. So it sees the file (probably) but wont acces any data in it (returning null).

I tried implement dependency:

implementation 'io.github.cdimascio:java-dotenv:5.2.2'

I tried get values with:

@Value("${JWT_SECRET_KEY}")
  private String jwtSecret;

and

System.getenv();

I tried remove .env from gitignore I tried different imports like:

spring.config.import=optional:file:.env[.properties]
spring.config.import=file:.env[.properties] 

in application.properties I tried add: JWT_SECRET_KEY=${JWT_SECRET_KEY} directly in application.properties. I tried @ComponentScan with path annotation I tried get values with import org.springframework.core.env.Environment; I tried use envFile plugin in Intellij

Im working in Intellij, using corretto-17, SpringBoot, Gradle. .env is in root dir of a project.

Answer 1

Spring only can read .properties and YAML files, which it determines based on the file extension. To read random files that are in properties format, you can create a custom property source as shown below.

Create a class that implements the EnvironmentPostProcessor interface and override the postProcessEnvironment() method. In this method, you can add the custom PropertySource to the Environment object.

public class CustomPropertySourceEnvironmentPostProcessor implements EnvironmentPostProcessor {

    @Override
    public void postProcessEnvironment(ConfigurableEnvironment environment, SpringApplication application) {
        PropertySource<?> customPropertySource = new PropertiesPropertySource("env", properties);
        environment.getPropertySources().addFirst(customPropertySource);
    }
}

The properties is a Java Properties object that you can create using Spring Resource injection.

@Value("classpath:.env")
private Resource resource;

How to turn a Resource into Properties is a fairly trivial exercise that I'll leave to you.