Скачать или смотреть How to Fix CsvReader Class Not Reading Filename from application.properties in Spring Boot

Learn how to resolve the issue with the `CsvReader` class not correctly reading the filename from `application.properties` in your Spring Boot application.
---
This video is based on the question https://stackoverflow.com/q/64629135/ asked by the user 'E-men' ( https://stackoverflow.com/u/10537305/ ) and on the answer https://stackoverflow.com/a/64629411/ provided by the user 'Niyas' ( https://stackoverflow.com/u/3441699/ ) 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: Spring boot: CsvReader class not reading filename from application.properties correctly

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.
---
Introduction

If you are getting started with Spring Boot, you may encounter issues integrating configuration files into your application. One common problem is having classes that don't read values from application.properties as intended. For example, you may find yourself hardcoding the file name in your CsvReader class, while you want to utilize a path defined in application.properties().

In this guide, we'll explore why your CsvReader class isn't reading the filename correctly from application.properties and discuss the solutions step by step.

Problem Overview

In your Spring Boot application setup, the file path for your CSV input file is defined within application.properties as:

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

You can correctly read this filename into the inputFilename field of your ValidationController class and display it on the /parameters webpage. However, the CsvReader class still utilizes a hardcoded file path:

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

This design defeats the purpose of using a centralized configuration file and produces issues when you want to dynamically change the input file location.

Solution: Making CsvReader Spring-Compatible

To solve the problem of the CsvReader class not reading the filename from application.properties, you have two viable options:

1. Use Dependency Injection

The first approach involves making the CsvReader a Spring-managed component, allowing you to inject the inputFilename directly.

Step-by-Step Implementation:

Annotate the CsvReader Class: Use the @ Component annotation to make it a Spring bean.

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

Inject Into Your Application: Modify ValidationApplication.java to call the read method on your CsvReader bean.

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

2. Pass Filename Through Constructor

Alternatively, if you prefer not to use Spring's dependency injection, you can pass the filename to the CsvReader via its constructor.

Step-by-Step Implementation

Modify the CsvReader Constructor:

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

Update ValidationApplication.java to Instantiate CsvReader:

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

Conclusion

By following the steps outlined in either method, you'll enable your CsvReader class to dynamically utilize the input filename defined in application.properties, which promotes cleaner code and improves maintainability. Spring Boot's bean system helps simplify configuration management, making your application easier to manage and update.

Now you can enjoy the benefits of having a well-structured and maintainable Spring Boot application.



If you have any further questions or need additional clarification, don't hesitate to reach out. Happy coding!