BAEL-5680: Guide to Check if Apache Kafka Server is Running (#12600)

Co-authored-by: Tapan Avasthi <tavasthi@Tapans-MacBook-Air.local>

apache-kafka-2/README.md

@@ -0,0 +1,6 @@
+## Apache Kafka
+
+This module contains articles about Apache Kafka.
+
+##### Building the project
+You can build the project from the command line using: *mvn clean install*, or in an IDE.

apache-kafka-2/log4j.properties

@@ -0,0 +1 @@
+log4j.rootLogger=INFO, stdout

apache-kafka-2/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>apache-kafka-2</artifactId>
+    <name>apache-kafka-2</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.kafka</groupId>
+            <artifactId>kafka-clients</artifactId>
+            <version>${kafka.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+            <version>${org.slf4j.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-log4j12</artifactId>
+            <version>${org.slf4j.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>kafka</artifactId>
+            <version>${testcontainers-kafka.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>${testcontainers-jupiter.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>net.java.dev.jna</groupId>
+            <artifactId>jna</artifactId>
+            <version>5.7.0</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>${lombok.version}</version>
+            <scope>provided</scope>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <kafka.version>2.8.0</kafka.version>
+        <testcontainers-kafka.version>1.15.3</testcontainers-kafka.version>
+        <testcontainers-jupiter.version>1.15.3</testcontainers-jupiter.version>
+        <lombok.version>1.18.20</lombok.version>
+    </properties>
+
+</project>

apache-kafka-2/src/main/java/com/baeldung/kafka/KafkaAdminClient.java

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+package com.baeldung.kafka;
+
+import java.util.Collection;
+import java.util.Properties;
+import java.util.concurrent.ExecutionException;
+
+import org.apache.kafka.clients.admin.AdminClient;
+import org.apache.kafka.common.Node;
+
+public class KafkaAdminClient {
+    private final AdminClient client;
+
+    public KafkaAdminClient(String bootstrap) {
+        Properties props = new Properties();
+        props.put("bootstrap.servers", bootstrap);
+        props.put("request.timeout.ms", 3000);
+        props.put("connections.max.idle.ms", 5000);
+
+        this.client = AdminClient.create(props);
+    }
+
+    public boolean verifyConnection() throws ExecutionException, InterruptedException {
+        Collection<Node> nodes = this.client.describeCluster()
+            .nodes()
+            .get();
+        return nodes != null && nodes.size() > 0;
+    }
+
+    public static void main(String[] args) throws ExecutionException, InterruptedException {
+        String defaultBootStrapServer = "localhost:9092";
+        KafkaAdminClient kafkaAdminClient = new KafkaAdminClient(defaultBootStrapServer);
+        System.out.println(kafkaAdminClient.verifyConnection());
+    }
+
+}

apache-kafka-2/src/test/java/com/baeldung/kafka/KafkaConnectionLiveTest.java

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+package com.baeldung.kafka;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.testcontainers.containers.KafkaContainer;
+import org.testcontainers.junit.jupiter.Container;
+import org.testcontainers.junit.jupiter.Testcontainers;
+import org.testcontainers.utility.DockerImageName;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+// This live test needs a running Docker instance so that a kafka container can be created
+
+@Testcontainers
+class KafkaConnectionLiveTest {
+
+    @Container
+    private static final KafkaContainer KAFKA_CONTAINER = new KafkaContainer(DockerImageName.parse("confluentinc/cp-kafka:5.4.3"));
+    private KafkaAdminClient kafkaAdminClient;
+
+    @BeforeEach
+    void setup() {
+        KAFKA_CONTAINER.addExposedPort(9092);
+        this.kafkaAdminClient = new KafkaAdminClient(KAFKA_CONTAINER.getBootstrapServers());
+    }
+
+    @AfterEach
+    void destroy() {
+        KAFKA_CONTAINER.stop();
+    }
+
+    @Test
+    void givenKafkaIsRunning_whenCheckedForConnection_thenConnectionIsVerified() throws Exception {
+        boolean alive = kafkaAdminClient.verifyConnection();
+        assertThat(alive).isTrue();
+    }
+
+}

pom.xml

@@ -338,6 +338,7 @@
 
                 <module>apache-cxf-modules</module>
                 <module>apache-kafka</module>
+                <module>apache-kafka-2</module>
                 <module>apache-libraries</module>
                 <module>apache-olingo</module>
                 <module>apache-poi</module>
@@ -769,6 +770,7 @@
 
                 <module>apache-cxf-modules</module>
                 <module>apache-kafka</module>
+                <module>apache-kafka-2</module>
                 <module>apache-libraries</module>
                 <module>apache-olingo</module>
                 <module>apache-poi</module>