A very lightweight configuration manager built along the lines of spring boot configuration (Without the overhead of spring)
You can get configuraion elements from different source with a well-defined heirarchy precedence.
The following is the configuration-source herirachy from top to bottom :
- System Property (example :
java -Dconfig.key=configValue - Environment Variable (example :
export config_key=configValue - Environment specific application-{env}.properties file
- application.properties file
To set the configuration environment,
- Set the system property
-Dio.github.sidgoyal.config.env=dev - Set the environment variable
io_github_sidgoyal_config_env=dev
A lot of traditional java properties are structured with . (ex : `service.endpoint=localhost)
such traditional java properties do not work very well with environemnt variables
So, Environment variables by default are separated by _
You can change the default separator by setting it in the builder :
new ConfigManagerBuilder().setEnvSeparator("__")
You can also add a prefix to the environment variables :
new ConfigManagerBuilder().setEnvPrefix("prefix")
Use ConfigManagerBuilder to build a ConfigManager instance
Load a property using the configurationManger instance:
configManager.getProperty("key");