Setting up a streaming application with platforms like Redpanda requires integration testing to ensure correct configuration, and two popular Java-based libraries for this purpose are Testcontainers and Zerocode. Testcontainers allows testing within Docker containers, making it suitable for simulating data streams using Redpanda nodes, while Zerocode offers a declarative testing approach through JSON/YAML scenarios, suitable for end-to-end testing of data streams. Both tools enable testing the functionality of producers and consumers, with Testcontainers requiring a Java setup and Docker knowledge, while Zerocode relies on scenario files and configurations. Successful integration testing confirms that data streams are properly configured, and any errors in the setup will be visible through test logs.