Creating a Kafka Java Project using Gradle (build.gradle)
Learn how to create a Java project using Gradle that can interact with Kafka cluster
Before developing Kafka producers and consumers in Java, we'll have to set up a simple Kafka Java project that includes common dependencies that we'll need, namely:
Kafka dependencies
Logging dependencies
Follow these steps to create a Java project with the above dependencies.
In IntelliJ IDEA, create a new Java Gradle project (File > New > Project)
Then add your Gradle project attributes
The build tool Gradle contains a build.gradle file. The build.gradle is a default Gradle file that carries all the information regarding the Group and Version values . The user needs to define all the necessary project dependencies in the build.gradle file. Go to the build.gradle file.
Define the Kafka Dependencies in the dependencies { ... } block.
Add a dependency for Kafka client and logging dependencies as shown below
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dependencies {
// https://mvnrepository.com/artifact/org.apache.kafka/kafka-clients
implementation 'org.apache.kafka:kafka-clients:3.0.0'
// https://mvnrepository.com/artifact/org.slf4j/slf4j-api
implementation 'org.slf4j:slf4j-api:1.7.32'
// https://mvnrepository.com/artifact/org.slf4j/slf4j-simple
implementation 'org.slf4j:slf4j-simple:1.7.32'
testImplementation 'org.junit.jupiter:junit-jupiter-api:5.6.0'
testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine'
}Load the Gradle changes with the menu from the right hand side to import the dependencies
Now, we have set all the required dependencies. Let's try the Simple Hello World example.
Create a java package say, io.conduktor.demos.kafka.HelloWorld
While creating the java package, follow the package naming conventions. Finally, create the sample application program as shown below.
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package io.conduktor.demos.kafka;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class HelloWorld {
private static final Logger log = LoggerFactory.getLogger(HelloWorld.class);
public static void main(String[] args) {
log.info("Hello World");
}
}Run the application (the play green button on line 9 in the screenshot below) and verify that it runs and prints the message, and exits with code 0. This means that your Java application has run successfully.
Expand the 'External Libraries' on the Project panel and verify that it displays the dependencies that we added for the project in build.gradle file
We have created a sample Java project that includes all the needed dependencies. This will form the basis for creating Java producers and consumers next.