Скачать или смотреть Resolving the Excessive Startup Time Issue in Spring Boot with Vaadin

Discover how to troubleshoot and resolve excessive startup times in your Spring Boot and Vaadin applications for a smoother development experience.
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Troubleshooting Excessive Startup Times in Spring Boot with Vaadin

When developing applications using Spring Boot and Vaadin, you may encounter an issue where the application takes an unusually long time to start, sometimes stretching over several minutes. For developers, this not only delays testing but can also hamper productivity. In this guide, we will explore the underlying reasons for this prolonged startup time and provide a step-by-step guide to resolving it effectively.

Understanding the Problem

A developer facing long startup times reported that, although they had tried several solutions to mitigate the issue, they were still experiencing delays during initialization, specifically between the processes of "Mapping servlets" and "Starting Frontend compilation." This gap could extend up to five minutes, making it difficult to manage the development cycle efficiently.

Their setup consisted of:

Spring Boot version: 2.4.4

Vaadin version: 14.3.9

Java version: 11

Development environment: STS 4.10 on Windows 10

With debugging enabled, the developer could see a clear delay between key application lifecycle events, but determining the cause remained elusive.

Analyzing the Configuration Issue

After seeking community insights, it became clear that the issue stemmed from a configuration error rather than from the frameworks themselves. The developer was using the YAML format for their application properties to whitelist packages. However, the format they used was not recognized as valid by Vaadin.

Incorrect Whitelisting Configuration

Initially, the developer set their whitelisted packages in the following incorrect way:

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

This format was auto-suggested by the IDE and led to confusion since it appeared correct at first glance.

Correct Whitelisting Configuration

The correct way to configure whitelisted packages in Vaadin is as follows:

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

If you have multiple packages to whitelist, separate them with commas:

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

Solution and Result

Upon correcting the package whitelist format, the application startup time improved drastically to just a few seconds. This simple change can save developers considerable time and improve the overall development workflow.

Conclusion

In summary, while long startup times in Spring Boot applications using Vaadin can appear daunting, often the root cause is linked to simple configuration errors. By ensuring correct settings and paying close attention to framework guidelines, developers can significantly improve their application startup times.

If you're experiencing similar issues, we urge you to review your configuration settings closely. Happy coding!