Implement review remarks

src/main/java/com/deviceinsight/kafka/health/KafkaConsumingHealthIndicator.java

@@ -2,9 +2,8 @@ package com.deviceinsight.kafka.health;
 
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 
-import com.deviceinsight.kafka.health.cache.CacheService;
+import com.github.benmanes.caffeine.cache.Cache;
-import com.deviceinsight.kafka.health.cache.CaffeineCacheServiceImpl;
+import com.github.benmanes.caffeine.cache.Caffeine;
-
 import com.google.common.annotations.VisibleForTesting;
 import org.apache.kafka.clients.consumer.Consumer;
 import org.apache.kafka.clients.consumer.ConsumerConfig;
@@ -35,6 +34,7 @@ import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
 import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.stream.StreamSupport;
@@ -44,8 +44,7 @@ import javax.annotation.PreDestroy;
 
 public class KafkaConsumingHealthIndicator extends AbstractHealthIndicator {
 
-	private static final Logger logger = LoggerFactory.getLogger(
+	private static final Logger logger = LoggerFactory.getLogger(KafkaConsumingHealthIndicator.class);
-			com.deviceinsight.kafka.health.KafkaConsumingHealthIndicator.class);
 	private static final String CONSUMER_GROUP_PREFIX = "health-check-";
 
 	private final Consumer<String, String> consumer;
@@ -59,7 +58,7 @@ public class KafkaConsumingHealthIndicator extends AbstractHealthIndicator {
 
 	private final ExecutorService executor;
 	private final AtomicBoolean running;
-	private final CacheService<String> cacheService;
+	private final Cache<String, String> cache;
 
 	private KafkaCommunicationResult kafkaCommunicationResult;
 
@@ -83,9 +82,13 @@ public class KafkaConsumingHealthIndicator extends AbstractHealthIndicator {
 
 		this.executor = Executors.newFixedThreadPool(2);
 		this.running = new AtomicBoolean(true);
-		this.cacheService = new CaffeineCacheServiceImpl(calculateCacheExpiration(sendReceiveTimeoutMs));
+		this.cache = Caffeine.newBuilder()
+				.expireAfterWrite(calculateCacheExpiration(sendReceiveTimeoutMs), TimeUnit.MILLISECONDS)
+				.recordStats()
+				.build();
 
-		this.kafkaCommunicationResult = KafkaCommunicationResult.failure(topic, new RejectedExecutionException("Kafka Health Check is starting."));
+		this.kafkaCommunicationResult = KafkaCommunicationResult.failure(topic,
+				new RejectedExecutionException("Kafka Health Check is starting."));
 	}
 
 	@PostConstruct
@@ -102,7 +105,7 @@ public class KafkaConsumingHealthIndicator extends AbstractHealthIndicator {
 			while (running.get()) {
 				if (messageNotReceived()) {
 					this.kafkaCommunicationResult = KafkaCommunicationResult.failure(topic,
-							new RejectedExecutionException("Ignore health check, already running..."));
+							new RejectedExecutionException("No message received."));
 				} else {
 					this.kafkaCommunicationResult = KafkaCommunicationResult.success(topic);
 				}
@@ -161,31 +164,21 @@ public class KafkaConsumingHealthIndicator extends AbstractHealthIndicator {
 
 	private void sendMessage() {
 
-		Future<Void> sendReceiveTask = null;
-
 		try {
-
+			sendKafkaMessage();
-			sendReceiveTask = executor.submit(() -> {
-				sendKafkaMessage();
-				return null;
-			});
-
-			sendReceiveTask.get(sendReceiveTimeoutMs, MILLISECONDS);
-			this.kafkaCommunicationResult = KafkaCommunicationResult.success(topic);
 
 		} catch (ExecutionException e) {
 			logger.warn("Kafka health check execution failed.", e);
 			this.kafkaCommunicationResult = KafkaCommunicationResult.failure(topic, e);
 		} catch (TimeoutException | InterruptedException e) {
 			logger.warn("Kafka health check timed out.", e);
-			sendReceiveTask.cancel(true);
 			this.kafkaCommunicationResult = KafkaCommunicationResult.failure(topic, e);
 		} catch (RejectedExecutionException e) {
 			logger.debug("Ignore health check, already running...");
 		}
 	}
 
-	private void sendKafkaMessage() throws Exception {
+	private void sendKafkaMessage() throws InterruptedException, ExecutionException, TimeoutException {
 
 		String message = UUID.randomUUID().toString();
 		long startTime = System.currentTimeMillis();
@@ -193,7 +186,7 @@ public class KafkaConsumingHealthIndicator extends AbstractHealthIndicator {
 		logger.debug("Send health check message = {}", message);
 
 		producer.send(new ProducerRecord<>(topic, message, message)).get(sendReceiveTimeoutMs, MILLISECONDS);
-		cacheService.write(message);
+		cache.put(message, message);
 
 		logger.debug("Kafka health check succeeded. took= {} msec", System.currentTimeMillis() - startTime);
 	}
@@ -201,7 +194,7 @@ public class KafkaConsumingHealthIndicator extends AbstractHealthIndicator {
 	private boolean messageNotReceived() {
 
 		return StreamSupport.stream(consumer.poll(Duration.ofMillis(pollTimeoutMs)).spliterator(), false)
-				.noneMatch(msg -> cacheService.get(msg.key()) == null);
+				.noneMatch(msg -> cache.getIfPresent(msg.key()) == null);
 	}
 
 

src/main/java/com/deviceinsight/kafka/health/cache/CacheService.java

@@ -1,8 +0,0 @@
-package com.deviceinsight.kafka.health.cache;
-
-public interface CacheService<T> {
-
-	void write(T entry);
-
-	T get(T entry);
-}

src/main/java/com/deviceinsight/kafka/health/cache/CaffeineCacheServiceImpl.java

@@ -1,28 +0,0 @@
-package com.deviceinsight.kafka.health.cache;
-
-import com.github.benmanes.caffeine.cache.Cache;
-import com.github.benmanes.caffeine.cache.Caffeine;
-
-import java.util.concurrent.TimeUnit;
-
-public class CaffeineCacheServiceImpl implements CacheService<String> {
-
-	private final Cache<String, String> cache;
-
-	public CaffeineCacheServiceImpl(long expireAfterWrite) {
-		this.cache = Caffeine.newBuilder()
-				.expireAfterWrite(expireAfterWrite, TimeUnit.MILLISECONDS)
-				.recordStats()
-				.build();
-	}
-
-	@Override
-	public void write(String entry) {
-		this.cache.put(entry, entry);
-	}
-
-	@Override
-	public String get(String entry) {
-		return this.cache.getIfPresent(entry);
-	}
-}