Скачать или смотреть Resolving the OptaPlanner Integration Issue with Spring Boot

Learn how to troubleshoot and fix the integration issue between `OptaPlanner` and `Spring Boot`, ensuring your app runs smoothly without exceptions.
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This video is based on the question https://stackoverflow.com/q/64050728/ asked by the user 'Billy Billy' ( https://stackoverflow.com/u/11475227/ ) and on the answer https://stackoverflow.com/a/64059299/ provided by the user 'Geoffrey De Smet' ( https://stackoverflow.com/u/472109/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Troubleshooting OptaPlanner Integration with Spring Boot

If you've recently attempted to integrate OptaPlanner into a Spring Boot application and encountered frustrating error messages, you're not alone! Many developers face this challenge due to package structure and file placement of configuration files. In this guide, we'll explore the common causes of the issue and how to resolve them effectively.

The Problem: Error Messages Explained

When you try to run your Spring Boot application, you may come across an error such as:

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

These messages indicate that Spring Boot cannot locate your ConstraintProvider class or the necessary constraints.drl rules file. This situation usually arises from how files and classes are structured within your project.

Understanding the Error Message

The crucial part of the error you should pay attention to is:

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

This indicates a failure in locating files essential for configuring and running OptaPlanner. Here’s what you should check and adjust:

Key Areas to Investigate

Package Structure:

Confirm that your @ ConstraintProvider class resides in a subpackage of the package where your @ SpringBootApplication class is declared.

Consider moving your ConstraintProvider class to the same package or a subpackage of your Application class.

Resource File Location:

Ensure that the constraints.drl file is correctly located in the resources directory (src/main/resources). For example, it should be in src/main/resources/org/optaplanner/examples.

Solver Configuration:

There might be misplacement of your solverConfig.xml file. This file should ideally be located at src/main/resources/solverConfig.xml. You can also specify its location via application.properties if it’s in a different path.

Solutions to Resolve the Issue

Move the Configuration File

To fix the path issue, move your configuration file as follows:

From: src/main/resources/org/optaplanner/examples/cloudBalancingSolverConfig.xml

To: src/main/resources/solverConfig.xml

Update the Rules File Reference

If your solverConfig.xml references a specific rules file, ensure that the path matches and follows this structure. You can:

Use directly the rules file as constraints.drl in appropriate directory without referencing fooScoreRules.drl.

Example Configuration

Your constraints.drl should be declared as:

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

Testing Your Changes

After implementing the suggested changes:

Clean and rebuild your project to ensure that all references are correctly updated.

Run your Spring Boot application again to confirm that the integration is successful.

Conclusion

Integrating OptaPlanner with Spring Boot can present some hurdles, primarily related to file structure and configuration pathways. By ensuring that your packages are aligned correctly and your configuration files are in their designated places, you can effectively eliminate the issues you're facing. Remember, clarity in structure can save you from a lot of headache in the long run. Happy coding!