import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;
+/**
+ * The class fetches incoming requests from DMAAP. It uses the timeout parameter
+ * that lets the MessageRouter keep the connection with the Kafka open until
+ * requests are sent in.
+ *
+ * <p>
+ * this service will regularly check the configuration and start polling DMaaP
+ * if the configuration is added. If the DMaaP configuration is removed, then
+ * the service will stop polling and resume checking for configuration.
+ *
+ * <p>
+ * Each received request is processed by {@link DmaapMessageHandler}.
+ */
@Component
-public class DmaapMessageConsumer implements Runnable {
+public class DmaapMessageConsumer {
+
+ protected static final Duration TIME_BETWEEN_DMAAP_RETRIES = Duration.ofSeconds(10);
private static final Logger logger = LoggerFactory.getLogger(DmaapMessageConsumer.class);
- final Duration TIME_BETWEEN_DMAAP_POLLS = Duration.ofSeconds(10);
private final ApplicationConfig applicationConfig;
- @Value("${server.port}")
- private int localServerPort;
+ private DmaapMessageHandler dmaapMessageHandler = null;
+ private MRConsumer messageRouterConsumer = null;
+
+ @Value("${server.http-port}")
+ private int localServerHttpPort;
@Autowired
public DmaapMessageConsumer(ApplicationConfig applicationConfig) {
this.applicationConfig = applicationConfig;
-
- Thread thread = new Thread(this);
- thread.start();
}
- private boolean isDmaapConfigured() {
- Properties consumerCfg = applicationConfig.getDmaapConsumerConfig();
- Properties producerCfg = applicationConfig.getDmaapPublisherConfig();
- return (consumerCfg != null && consumerCfg.size() > 0 && producerCfg != null && producerCfg.size() > 0);
+ /**
+ * Starts the consumer. If there is a DMaaP configuration, it will start polling
+ * for messages. Otherwise it will check regularly for the configuration.
+ *
+ * @return the running thread, for test purposes.
+ */
+ public Thread start() {
+ Thread thread = new Thread(this::messageHandlingLoop);
+ thread.start();
+ return thread;
}
- @Override
- public void run() {
- while (sleep(TIME_BETWEEN_DMAAP_POLLS) && isDmaapConfigured()) {
+ private void messageHandlingLoop() {
+ while (!isStopped()) {
try {
- Iterable<String> dmaapMsgs = fetchAllMessages();
- if (dmaapMsgs != null && Iterables.size(dmaapMsgs) > 0) {
- logger.debug("Fetched all the messages from DMAAP and will start to process the messages");
- for (String msg : dmaapMsgs) {
- processMsg(msg);
+ if (isDmaapConfigured()) {
+ Iterable<String> dmaapMsgs = fetchAllMessages();
+ if (dmaapMsgs != null && Iterables.size(dmaapMsgs) > 0) {
+ logger.debug("Fetched all the messages from DMAAP and will start to process the messages");
+ for (String msg : dmaapMsgs) {
+ processMsg(msg);
+ }
}
+ } else {
+ sleep(TIME_BETWEEN_DMAAP_RETRIES); // wait for configuration
}
} catch (Exception e) {
- logger.warn("{}: cannot fetch because of ", this, e.getMessage(), e);
- sleep(TIME_BETWEEN_DMAAP_POLLS);
+ logger.warn("Cannot fetch because of {}", e.getMessage());
+ sleep(TIME_BETWEEN_DMAAP_RETRIES);
}
}
}
- private Iterable<String> fetchAllMessages() throws ServiceException, IOException {
+ protected boolean isStopped() {
+ return false;
+ }
+
+ protected boolean isDmaapConfigured() {
+ Properties consumerCfg = applicationConfig.getDmaapConsumerConfig();
+ Properties producerCfg = applicationConfig.getDmaapPublisherConfig();
+ return (consumerCfg != null && consumerCfg.size() > 0 && producerCfg != null && producerCfg.size() > 0);
+ }
+
+ protected Iterable<String> fetchAllMessages() throws ServiceException, IOException {
Properties dmaapConsumerProperties = this.applicationConfig.getDmaapConsumerConfig();
- MRConsumer consumer = MRClientFactory.createConsumer(dmaapConsumerProperties);
+ MRConsumer consumer = getMessageRouterConsumer(dmaapConsumerProperties);
MRConsumerResponse response = consumer.fetchWithReturnConsumerResponse();
if (response == null || !"200".equals(response.getResponseCode())) {
- throw new ServiceException("DMaaP NULL response received");
+ String errorMessage = "DMaaP NULL response received";
+ if (response != null) {
+ errorMessage = "Error respons " + response.getResponseCode() + " " + response.getResponseMessage()
+ + " from DMaaP.";
+ }
+ throw new ServiceException(errorMessage);
} else {
logger.debug("DMaaP consumer received {} : {}", response.getResponseCode(), response.getResponseMessage());
return response.getActualMessages();
private void processMsg(String msg) throws IOException {
logger.debug("Message Reveived from DMAAP : {}", msg);
- createDmaapMessageHandler().handleDmaapMsg(msg);
+ getDmaapMessageHandler().handleDmaapMsg(msg);
}
- private DmaapMessageHandler createDmaapMessageHandler() throws IOException {
- String agentBaseUrl = "http://localhost:" + this.localServerPort;
- AsyncRestClient agentClient = new AsyncRestClient(agentBaseUrl);
- Properties dmaapPublisherProperties = applicationConfig.getDmaapPublisherConfig();
- MRBatchingPublisher producer = MRClientFactory.createBatchingPublisher(dmaapPublisherProperties);
-
- return new DmaapMessageHandler(producer, agentClient);
+ protected DmaapMessageHandler getDmaapMessageHandler() throws IOException {
+ if (this.dmaapMessageHandler == null) {
+ String agentBaseUrl = "http://localhost:" + this.localServerHttpPort;
+ AsyncRestClient agentClient = new AsyncRestClient(agentBaseUrl);
+ Properties dmaapPublisherProperties = applicationConfig.getDmaapPublisherConfig();
+ MRBatchingPublisher producer = MRClientFactory.createBatchingPublisher(dmaapPublisherProperties);
+ this.dmaapMessageHandler = new DmaapMessageHandler(producer, agentClient);
+ }
+ return this.dmaapMessageHandler;
}
- private boolean sleep(Duration duration) {
+ protected void sleep(Duration duration) {
try {
Thread.sleep(duration.toMillis());
- return true;
} catch (Exception e) {
logger.error("Failed to put the thread to sleep", e);
- return false;
}
}
+
+ protected MRConsumer getMessageRouterConsumer(Properties dmaapConsumerProperties) throws IOException {
+ if (this.messageRouterConsumer == null) {
+ this.messageRouterConsumer = MRClientFactory.createConsumer(dmaapConsumerProperties);
+ }
+ return this.messageRouterConsumer;
+ }
+
}