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Retrieving a configuration

To retrieve a configuration from Gestalt we need the path to the configuration as well as what type of class.

getConfig path options​

Gestalt is not case sensitive. Since Gestalt interops between Environment Variables and other sources with various cases, all strings in Gestalt are normalized to a lower case. By default, Gestalt uses dot notation and allows indexing into arrays using a '[0]'.
If you want to use a different path style you can provide your own custom lexer to Gestalt. The SentenceLexer is used to convert the path passed to the Gestalt getConfig interface into tokens that Gestalt can use to navigate to your sub node.

  // load a whole class, this works best with pojo's
  HttpPool pool = gestalt.getConfig("http.pool", HttpPool.class);
  // or get a specific config value from a class
  short maxTotal  gestalt.getConfig("HTTP.pool.maxTotal", Short.class);
  // get with a default if you want a fallback from code
  long maxConnectionsPerRoute = gestalt.getConfig("http.Pool.maxPerRoute", 24, Long.class);

  // get a list of Host objects, or an PlaceHolder collection if there is no hosts found.
  LinkedList<Host> hosts = gestalt.getConfig("db.hosts", new LinkedList(), new TypeCapture<LinkedList<Host>>() {});

  // Get a class at a specific list index. 
  Host host = gestalt.getConfig("db.hosts[2]", Host.class);
  // get a value of a class from a specific list index.
  String password = gestalt.getConfig("db.hosts[2].password", String.class);

When decoding a path we do use path mappers to try different cases, but that only applies to the sub-tree starting at the path asked for. So if you call gestalt.getConfig("http.pool", HttpPool.class) it will try and map the cases for nodes under path http.pool but not the nodes in the path http-pool.

  // given the record. 
  public record HttpPool(String poolSize, int timeout) {}

And the properties:

booking.service.pool.size = 10
booking-service.timeout = 10

When getting the config will fail, because booking.service will not match booking-service so it will not find the timeout.

  HttpPool pool = gestalt.getConfig("booking.service", HttpPool.class);

But given the properties

booking.service.pool.size = 10
booking.service.timeout = 10

These calls will succeed. When decoding poolSize it will first try a lowercase match of poolsize, but will not find the node, so it will try pool.size for a combined path of booking.service.pool.size which it will find.

  HttpPool pool = gestalt.getConfig("booking.service", HttpPool.class);

Retrieving Primitive and boxed types​

Getting primitive and boxed types involves calling Gestalt and providing the class of the type you are trying to retrieve.

Short myShortWrapper = gestalt.getConfig("http.pool.maxTotal", Short.class);
short myShort = gestalt.getConfig("http.pool.maxTotal", short.class);
String serviceMode = gestalt.getConfig("serviceMode", String.class);

Gestalt will automatically decode and provide the value in the type you requested.