...
Sample usage:
| Code Block | ||||
|---|---|---|---|---|
| ||||
// Generate RequestID and InvocationID which will be used when logging and in HTTP requests
RequestDiagnosticContext diagnosticContext = RequestDiagnosticContext.create();
// Read necessary properties from the environment
final EnvProperties env = EnvProperties.fromEnvironment();
// Create the client and use it to get the configuration
CbsClientFactory.createCbsClient(env)
.flatMap(cbsClient -> cbsClient.get(diagnosticContext))
.subscribe(
jsonObject -> {
// do a stuff with your JSON configuration using GSON API
final int port = Integer.parseInt(jsonObject.get("collector.listen_port").getAsString());
// ...
},
throwable -> {
logger.warn("Ooops", throwable);
}); |
Note that a subscribe handler can/will be called in separate thread asynchronously after CBS address lookup succeeds and CBS service call returns a result.
If you are interested in calling CBS periodically and react only when the configuration changed you can use updates method:
| Code Block | ||||
|---|---|---|---|---|
| ||||
// Generate RequestID and InvocationID which will be used when logging and in HTTP requests
RequestDiagnosticContext diagnosticContext = RequestDiagnosticContext.create();
// Read necessary properties from the environment
final EnvProperties env = EnvProperties.fromEnvironment();
// Polling properties
final Duration initialDelay = Duration.ofSeconds(5);
final Duration period = Duration.ofMinutes(1);
// Create the client and use it to get the configuration
CbsClientFactory.createCbsClient(env)
.flatMapMany(cbsClient -> cbsClient.updates(diagnosticContext, initialDelay, period))
.subscribe(
jsonObject -> {
// do a stuff with your JSON configuration using GSON API
final int port = Integer.parseInt(jsonObject.get("collector.listen_port").getAsString());
// ...
},
throwable -> {
logger.warn("Ooops", throwable);
}); |
The most significant change is in line 13. We are using flatMapMany since we want to map one CbsClient to many JsonObject updates. After 5 seconds CbsClient will call CBS every minute. If the configuration has changed it will pass the JsonObject downstream - in our case consumer of JsonObject will be called.
Notes about reactive programming
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