javadotenv

Just loads your environment variables from your .env file.

Javadotenv was inspired on dotenv for Node.js and dotenv for Ruby.

It works with Java 6+ versions and its only dependency is Sl4j.

Not separating config from code is a violation of The Twelve-Factor App methodology.

Usage

First create your .env file and place it under your default package. If you are using gradle or maven, it should be under src/main/resources. This file follows the Java properties format:

KEY=VALUE
DATABASE_URL=VALUE2

As earlier as possible, load your .env file.

new Dotenv.Builder().build().load();

Now, these properties should be accessible through System.getenv static method.

Configuration

resource

It is also possible to specify the resource to be loaded:

new Dotenv.Builder().resource(".env.other").build().load();

The only constraint is that this file should be acessible via ClassPath.

silent

When your .env or specified file is not available, it will log a warn message. If you don't want to see this message, this is what you have to do:

new Dotenv.Builder().silent(true).build().load();

FAQ

Should I commit my .env file?

My advice is No. It will prevent situations where you have Production pointing to Development keys. And please, make sure you add the .env to your .gitignore file.

When should I run it?

My advice is to run as soon as possible. If you have access to the main method, then it should be the first line of it.

What I should do if I am using Tomcat?

If you are using Tomcat or a similar web container, you can add a ServletContextListener and register it in the web.xml, preferably in the beginning of it:

<listener>
  <listener-class>
    com.myapp.listener.DotenvContextListener
  </listener-class>
</listener>

package com.myapp.listener;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

public class DotenvContextListener implements ServletContextListener {

  @Override
  public void contextInitialized(ServletContextEvent arg0) {
      new Dotenv.Builder().build().load();
  }

  public void contextDestroyed(ServletContextEvent arg0) {  }

}