How to Use Maven Random Port in Java Cucumber Tests

Описание: Learn how to effectively set a random port in your Java Cucumber tests using Maven plugins, ensuring smooth integration testing with Kafka and services.
---
This video is based on the question https://stackoverflow.com/q/76628419/ asked by the user 'paul' ( https://stackoverflow.com/u/854207/ ) and on the answer https://stackoverflow.com/a/76628507/ provided by the user 'Freeman' ( https://stackoverflow.com/u/252518/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Use maven random port in java cucumber test

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
How to Use Maven Random Port in Java Cucumber Tests

When developing microservices or applications that rely on communication between services and brokers like Kafka, it's common to face the challenge of managing server ports. Specifically, when running tests, you want to avoid port conflicts. A popular solution is to leverage Maven to allocate a random port dynamically. In this guide, we'll explore how to accomplish this in your Java Cucumber tests using the build-helper-maven-plugin and maven-surefire-plugin.

The Problem: Null Value for Service Port

Suppose you are using a Maven plugin to reserve random ports for your service and Kafka. After configuring your project, you may encounter an issue where you’re trying to access the port through System.getProperty("service.port") in your Cucumber steps, but you keep receiving a null value. This can be frustrating and lead to failed tests or, worse, misleading outcomes.

The Solution: Proper Configuration

To resolve this issue, you need to ensure the captured ports are correctly passed down to your testing phase. Here’s how to achieve that by following these steps:

1. Plugin Configuration

You must first define two relevant plugins in your pom.xml:

Build Helper Plugin

This plugin reserves the specified ports during the build phase.

[[See Video to Reveal this Text or Code Snippet]]

Surefire Plugin

This plugin is utilized to execute your integration tests. Importantly, you need to specify the argument line to pass in the random port.

[[See Video to Reveal this Text or Code Snippet]]

2. Adjust Execution Order

If you still encounter issues, ensure the order of execution in your <plugins> section allows for the build-helper-maven-plugin to execute before the maven-surefire-plugin. This change ensures that the ports are reserved before trying to run the tests.

3. Update Your Test Code

Within your Cucumber step definitions, you can now retrieve the port seamlessly:

[[See Video to Reveal this Text or Code Snippet]]

This should return the dynamically allocated port number instead of null.

Conclusion

By correctly configuring Maven plugins and their execution order, you can successfully reserve random ports for your services during integration tests with Cucumber. This allows for a smooth testing experience without port conflicts. Implement these changes and you should be well on your way to resolving your port issue!

Good luck with your testing and integration!