A twelve-factor configuration library for Java 8+.
Features:
- seamless integration with Guice (prefer Spring? see here);
- zero dependencies;
- available in Maven Central.
<dependency>
<groupId>com.github.shyiko.dotenv</groupId>
<artifactId>dotenv</artifactId>
<version>0.1.1</version>
</dependency>ENV resolution order (sources higher in the list take precedence over those located lower):
- System.getenv()
.envfile in current working directory (might not exist).envfile on the classpath
(java example)
Let's assume you have a jar file (say app.jar) which contains .env file (e.g. printf "SCHEME=http\nHOST=localhost\n# comment\nPORT=8080" > src/main/resources/.env) and Main.java with the following public static void main(...):
Map<String, String> dotEnv = DotEnv.load();
System.out.println(dotEnv.get("SCHEME") + "://" + dotEnv.get("HOST") + ":" + dotEnv.get("PORT"))Executing the following
printf "HOST=0.0.0.0" > .env
PORT=5050 app.jarwill then output http://0.0.0.0:5050
Integration with Guice
<dependency>
<groupId>com.github.shyiko.dotenv</groupId>
<artifactId>dotenv-guice</artifactId>
<version>0.1.1</version>
</dependency>(Main.java)
static class S {
private final String scheme;
private final String host;
private final int port;
@Inject
public S(
@DotEnvValue("SCHEME") String scheme,
@DotEnvValue("HOST") String host,
@DotEnvValue("PORT") int port
) {
this.scheme = scheme;
this.host = host;
this.port = port;
}
public void run() {
System.out.println(scheme + "://" + host + ":" + port);
}
}
public static void main(String[] args) {
Injector injector = Guice.createInjector(new DotEnvModule()/*, ... */);
S s = injector.getInstance(S.class);
s.run();
}Integration with Spring
(Main.java)
static class S {
private final String scheme;
private final String host;
private final int port;
@Autowired
public S(
@Value("${SCHEME}") String scheme,
@Value("${HOST}") String host,
@Value("${PORT}") int port
) {
this.scheme = scheme;
this.host = host;
this.port = port;
}
public void run() {
System.out.println(scheme + "://" + host + ":" + port);
}
}
public static void main(String[] args) {
ConfigurableApplicationContext ctx = new AnnotationConfigApplicationContext();
ctx.getEnvironment().getPropertySources().addFirst(
new MapPropertySource("dotenv", new HashMap<>(DotEnv.load()))
);
ctx.refresh();
S s = ctx.getBeanFactory().createBean(S.class);
s.run();
}git clone https://github.com/shyiko/dotenv && cd dotenv
./mvnw # shows how to build, test, etc. projectAll code, unless specified otherwise, is licensed under the MIT license.
Copyright (c) 2017 Stanley Shyiko.