How to Handle Deprecated Jwts.parser() in Java 21 with Spring Security

Описание: Learn how to adapt your JWT token handling in Spring Security with Java 21 as `Jwts.parser()` and related methods are deprecated.
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Handling Deprecated Jwts.parser() in Java 21 with Spring Security

In recent updates to Java libraries, particularly with the introduction of Java 21, it's not uncommon to encounter some methods within libraries that you might be using being deprecated. One such instance is the Jwts.parser() method within the JJWT library when working with JWT (JSON Web Tokens) in a Spring Security context. This can lead to confusion, especially for developers who are learning and implementing JWTs in their applications. This post will guide you through this problem and present a solution that complies with the latest practices.

The Problem: Deprecated Methods in JJWT

When following a guide on Spring Security and JWTs, you might have come across code segments that look like this:

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

This approach has served many developers well, but as of Java 21 and the latest version of the JJWT library (0.12.5), several commonly used methods are marked as deprecated, including:

getBody()

parseSignedClaims()

setSigningKey()

Such deprecations can create uncertainty when trying to authenticate and authorize users via JWTs in your Spring Boot applications. Many developers have reached out for help in adapting to these changes effectively, and this post will address exactly that.

The Solution: Updated Code for JWT Claims Extraction

To handle the deprecated methods effectively, you can use new approaches that align with the recommended practices for your JWT handling. Here’s how you can update your methods.

Extracting Claims

First, the method to extract claims from a JWT token needs to be rewritten as follows:

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

With this new method, we’ve replaced setSigningKey with verifyWith, and changed getBody() to getPayload(), ensuring compatibility with the newer versions of the JJWT library.

Generating a JWT Token

Furthermore, let’s revise the token generation method to ensure it adheres to best practices. It should look as follows:

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

This method is still valid and can be used to generate a new JWT token for a user upon authentication.

Conclusion

Navigating through deprecated methods in libraries can be challenging, especially for those still grasping the concepts of Spring Security and JWTs. However, by adapting your code to use verifyWith and getPayload(), you can ensure your application remains up-to-date with the latest practices in the Java ecosystem.

Feel free to reach out if you have any further questions or need clarification on JWT handling in Spring Security! Happy coding!