io.vertx.config

Interface ConfigRetriever

public interface ConfigRetriever

Defines a configuration retriever that read configuration from ConfigStore and tracks changes periodically.

Author:

Clement Escoffier

Method Summary

Modifier and Type	Method and Description
void	close() Closes the retriever.
ReadStream<JsonObject>	configStream()
static ConfigRetriever	create(Vertx vertx) Creates an instance of the default implementation of the ConfigRetriever, using the default settings (json file, system properties and environment variables).
static ConfigRetriever	create(Vertx vertx, ConfigRetrieverOptions options) Creates an instance of the default implementation of the ConfigRetriever.
JsonObject	getCachedConfig() Gets the last computed configuration.
Future<JsonObject>	getConfig() Like getConfig(Handler) but returns a Future of the asynchronous result
void	getConfig(Handler<AsyncResult<JsonObject>> completionHandler) Reads the configuration from the different ConfigStore and computes the final configuration.
void	listen(Handler<ConfigChange> listener) Registers a listener receiving configuration changes.
ConfigRetriever	setBeforeScanHandler(Handler<Void> handler) Registers a handler called before every scan.
ConfigRetriever	setConfigurationProcessor(java.util.function.Function<JsonObject,JsonObject> processor) Registers a handler that process the configuration before being injected into getConfig(Handler) or listen(Handler).

Method Detail

create

static ConfigRetriever create(Vertx vertx,
                              ConfigRetrieverOptions options)

Creates an instance of the default implementation of the ConfigRetriever.

Parameters:

vertx - the vert.x instance

options - the options, must not be null, must contain the list of configured store.

Returns:

the created instance.

create

static ConfigRetriever create(Vertx vertx)

Creates an instance of the default implementation of the ConfigRetriever, using the default settings (json file, system properties and environment variables).

Parameters:

vertx - the vert.x instance

Returns:

the created instance.

getConfig

void getConfig(Handler<AsyncResult<JsonObject>> completionHandler)

Reads the configuration from the different ConfigStore and computes the final configuration.

Parameters:

completionHandler - handler receiving the computed configuration, or a failure if the configuration cannot be retrieved

getConfig

Future<JsonObject> getConfig()

Like getConfig(Handler) but returns a Future of the asynchronous result

close

void close()

Closes the retriever.

getCachedConfig

JsonObject getCachedConfig()

Gets the last computed configuration.

Returns:

the last configuration

listen

void listen(Handler<ConfigChange> listener)

Registers a listener receiving configuration changes. This method cannot only be called if the configuration is broadcasted.

Parameters:

listener - the listener

setBeforeScanHandler

ConfigRetriever setBeforeScanHandler(Handler<Void> handler)

Registers a handler called before every scan. This method is mostly used for logging purpose.

Parameters:

handler - the handler, must not be null

Returns:

the current config retriever

setConfigurationProcessor

ConfigRetriever setConfigurationProcessor(java.util.function.Function<JsonObject,JsonObject> processor)

Registers a handler that process the configuration before being injected into getConfig(Handler) or listen(Handler). This allows the code to customize the configuration.

Parameters:

processor - the processor, must not be null. The method must not return null. The returned configuration is used. If the processor does not update the configuration, it must return the input configuration. If the processor throws an exception, the failure is passed to the getConfig(Handler) handler.

Returns:

the current config retriever

configStream

ReadStream<JsonObject> configStream()

Returns:

the stream of configurations. It's single stream (unicast) and that delivers the last known config and the successors periodically.