Скачать или смотреть How to Fix the java.lang.IllegalArgumentException for LocalDateTime in Spring Boot

Discover the solution to the `java.lang.IllegalArgumentException` encountered while working with `LocalDateTime` in Java Spring Boot applications. Learn step-by-step how to format your date parameters correctly.
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This video is based on the question https://stackoverflow.com/q/72811739/ asked by the user 'Kirill_Yudaev' ( https://stackoverflow.com/u/19449773/ ) and on the answer https://stackoverflow.com/a/72812365/ provided by the user 'Lazaros Chatzimichalakis' ( https://stackoverflow.com/u/18187974/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Understanding the java.lang.IllegalArgumentException Issue in Spring Boot

As a beginner in Java, encountering exceptions can be quite daunting. One common problem you might run into when using Spring Boot, Hibernate, and Java's LocalDateTime is the java.lang.IllegalArgumentException. This exception indicates that the parameter value you are trying to pass does not match the expected type. Specifically, you might see an error message like:

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

In this post, we'll explore the root cause of this issue and provide you with a clear solution to resolve it effectively.

The Problem Explained

In your case, the exception arises during a GET request intended to fetch data based on the provided local date and time parameter (2019-05-15,23:00). Here’s an outline of the relevant parts of your code:

You have a LocalDateTime variable named dateTimeAppointment in your entity model, which is annotated to expect a timestamp.

Your ClientController handles GET requests and calls the CriteriaService to retrieve clients based on the provided parameter pair (name, value).

The exception indicates that the value you provided does not conform to the LocalDateTime type, leading to an unsupported format error.

Understanding these points can help you identify what went wrong.

Solution: Formatting the DateTime Parameter

The heart of the solution lies in correctly parsing the date string into the LocalDateTime format that Java expects. Here's how you can fix it step-by-step:

Step 1: Create a DateTimeFormatter

You will need to define a DateTimeFormatter that matches the way your date and time string is formatted. Since your input is 2019-05-15,23:00, you should set up the formatter as follows:

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

This formatter will allow you to correctly interpret the input string.

Step 2: Parse the String into LocalDateTime

Once you have your formatter, you can parse the value that you receive from the request parameters. Modify your code in the CriteriaService class:

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

Complete Implementation Example

Here’s how the modified CriteriaService could look:

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

Conclusion

By following these steps, you should be able to resolve the java.lang.IllegalArgumentException and correctly handle LocalDateTime values in your Spring Boot application. Remember to always ensure that the date formats both in your input parameters and the Java application logic are aligned.

With this newfound knowledge, you can move forward in your Java journey with confidence. Happy coding!