CoralConfig is a configuration framework that offers a fluent API, aliases, deprecation support, default values, strongly typed configuration types (including enum), and more. It provides a robust solution to manage the many configuration parameters and their types that applications typically require.
public class Basics {
public static final ConfigKey<Integer> MAX_RETRIES = intKey().def(4); // or intKey(4)
private final int maxRetries;
public Basics(Configuration config) {
this.maxRetries = config.get(MAX_RETRIES);
}
}To create an empty configuration:
MapConfiguration mc = new MapConfiguration(Basics.class);To get the default value:
int maxRetries = mc.get(MAX_RETRIES); // => 4 (the default)To overwrite a default value:
mc.overwriteDefault(MAX_RETRIES, 6);
int maxRetries = mc.get(MAX_RETRIES); // => 6 (overwritten default)To configure (add) a value so this value is returned instead of the (overwritten or not) default value:
mc.add(MAX_RETRIES, 2);
int maxRetries = mc.get(MAX_RETRIES); // => 2 (configured)To create a configuration with some values, you can pass a list of params to the constructor:
MapConfiguration mc = new MapConfiguration("maxRetries=1 username=saoj heartbeat=30",
Basics.class);
int maxRetries = mc.get(MAX_RETRIES); // => 1 (configured)The configuration can handle multiple holder classes with distinct configuration keys. The configuration enforces that there are no duplicate keys in each holder class as well as across all holder classes.
public class Client {
public static final ConfigKey<Integer> HEARTBEAT = intKey(5);
}
public class TcpClient extends Client {
public static final ConfigKey<String> USERNAME = stringKey().def("saoj");
}Simply pass a list of holder classes:
MapConfiguration mc = new MapConfiguration("heartbeat=2 username=rpaiva",
Client.class, TcpClient.class);If you get the type of the config key wrong, it won't even compile:
// DOESN'T COMPILE (wrong type)
String maxRetries = mc.get(MAX_RETRIES);Don't like the name of a configuration key? Simply create an alias:
public class Client {
public static final ConfigKey<Integer> HEARTBEAT_INTERVAL = intKey().def(5);
public static final ConfigKey<Integer> HEARTBEAT = intKey().alias(HEARTBEAT_INTERVAL);
}We did not like the name heartbeat so we created heartbeatInterval as the primary config key and added heartbeat as an alias for backwards compatibility. Now we can do:
MapConfiguration mc = new MapConfiguration(Client.class);
int heartbeatInterval = mc.get(HEARTBEAT_INTERVAL); // => 5 (default)
// This also works with the default value of the primary config key!
int heartbeat = mc.get(HEARTBEAT); // => 5 (default)And if you declare a value for the new config key heartbeatInterval then the primary key together with all its aliases will get the declared value:
mc.add(HEARTBEAT_INTERVAL, 2);
int heartbeatInterval = mc.get(HEARTBEAT_INTERVAL); // => 2 (configured)
// The alias also gets the declared value!
int heartbeat = mc.get(HEARTBEAT); // => 2 (configured)or if you do this instead:
mc.add(HEARTBEAT, 2);
// The primary key gets the value declared for its alias!
int heartbeatInterval = mc.get(HEARTBEAT_INTERVAL); // => 2 (configured)
int heartbeat = mc.get(HEARTBEAT); // => 2 (configured)You can have as many aliases as you want:
public class Client {
public static final ConfigKey<Integer> HEARTBEAT_INTERVAL = intKey().def(5);
public static final ConfigKey<Integer> HEARTBEAT = intKey().alias(HEARTBEAT_INTERVAL);
public static final ConfigKey<Integer> HEARTBEAT_TIME = intKey().alias(HEARTBEAT_INTERVAL);
}Chose a bad name for a configuration? Simply deprecate it:
public class Client {
public static final ConfigKey<Integer> HEARTBEAT_INTERVAL = intKey().def(5);
public static final ConfigKey<Integer> HEARTBEAT = intKey().deprecated(HEARTBEAT_INTERVAL);
}We chose a bad name by mistake (heartbeat) so we created heartbeatInterval as the primary config key and added heartbeat as deprecated for backwards compatibility. Now we can do:
MapConfiguration mc = new MapConfiguration(Client.class);
int heartbeatInterval = mc.get(HEARTBEAT_INTERVAL); // => 5 (default)
// This also works with the default value of the primary config key!
int heartbeat = mc.get(HEARTBEAT); // => 5 (default)And if you declare a value for the new config key heartbeatInterval then the primary key together with all its deprecated keys will get the declared value:
mc.add(HEARTBEAT_INTERVAL, 2);
int heartbeatInterval = mc.get(HEARTBEAT_INTERVAL); // => 2 (configured)
// The deprecated key also gets the declared value!
int heartbeat = mc.get(HEARTBEAT); // => 2 (configured)or if you do this instead:
mc.add(HEARTBEAT, 2);
// The primary key gets the value declared for its deprecated keys!
int heartbeatInterval = mc.get(HEARTBEAT_INTERVAL); // => 2 (configured)
int heartbeat = mc.get(HEARTBEAT); // => 2 (configured)You can have as many deprecated configuration keys as you want:
public class Client {
public static final ConfigKey<Integer> HEARTBEAT_INTERVAL = intKey().def(5);
public static final ConfigKey<Integer> HEARTBEAT = intKey().deprecated(HEARTBEAT_INTERVAL);
public static final ConfigKey<Integer> HEARTBEAT_TIME = intKey().deprecated(HEARTBEAT_INTERVAL);
}And finally, if you want to know the deprecated configuration keys that you are still using, you can add a DeprecatedListener to your configuration. Below a full example:
public class DeprecationBasics {
public static final ConfigKey<Integer> MAX_NUMBER_OF_RETRIES = intKey().def(4);
public static final ConfigKey<Integer> MAX_RETRIES = intKey().deprecated(MAX_NUMBER_OF_RETRIES);
private final int maxRetries;
public DeprecationBasics(Configuration config) {
this.maxRetries = config.get(MAX_RETRIES); // using deprecated key!
}
public static void main(String[] args) {
MapConfiguration config = new MapConfiguration(DeprecationBasics.class);
DeprecatedListener listener = new DeprecatedListener() {
@Override
public void deprecatedConfig(ConfigKey<?> deprecatedKey, ConfigKey<?> primaryKey) {
DeprecatedListener.super.deprecatedConfig(deprecatedKey, primaryKey);
}
};
config.addListener(listener);
new DeprecationBasics(config);
}
}When you run the program above you see in the stdout:
---CoralConfig---> You are using a deprecated config key!
holder=com.coralblocks.coralconfig.example.DeprecationBasics
deprecatedKey=MAX_RETRIES("maxRetries")
inFavorOf=MAX_NUMBER_OF_RETRIES("maxNumberOfRetries")
@Test
public void testEnum() {
enum TestEnum { BALL, BOB, BILL }
class Base {
public static final ConfigKey<TestEnum> MY_ENUM = enumKey(TestEnum.class, TestEnum.BOB);
}
MapConfiguration mc = new MapConfiguration(Base.class);
assertEquals(TestEnum.BOB, mc.get(Base.MY_ENUM)); // test default
mc.overwriteDefault(Base.MY_ENUM, TestEnum.BILL);
assertEquals(TestEnum.BILL, mc.get(Base.MY_ENUM)); // test overwritten default
mc.add(Base.MY_ENUM, TestEnum.BALL);
assertEquals(TestEnum.BALL, mc.get(Base.MY_ENUM)); // test configured
mc.remove(Base.MY_ENUM);
assertEquals(TestEnum.BILL, mc.get(Base.MY_ENUM)); // test overwritten default
mc.overwriteDefault(Base.MY_ENUM, null); // String and Enum support NULL !!!
assertEquals(null, mc.get(Base.MY_ENUM)); // test overwritten default
mc.removeOverwrittenDefault(Base.MY_ENUM);
assertEquals(TestEnum.BOB, mc.get(Base.MY_ENUM)); // test default
}