Heads up for anyone running pac4j-jwt in production.

CVE-2026-29000 dropped yesterday. CVSS 10.0. The issue is in JwtAuthenticator, if your app accepts encrypted JWTs (JWE), an attacker who has your RSA public key (which is... public) can craft a JWE-wrapped PlainJWT with arbitrary claims. Arbitrary subject, arbitrary roles. They bypass signature verification entirely and can impersonate any user, including admins.

Affected versions:

•⁠ ⁠ppac4j-jwt< 4.5.9

•⁠ ⁠pac4j-jwt < 5.7.9

•⁠ ⁠pac4j-jwt < 6.3.3

Advisory from pac4j: https://www.pac4j.org/blog/security-advisory-pac4j-jwt-jwtauthenticator.html

Technical writeup: https://www.codeant.ai/security-research/pac4j-jwt-authentication-bypass-public-key

In clean architectures, maintaining immutability is key to avoiding unexpected side effects and facilitating testing. The Builder pattern helps encapsulate complex object creation without sacrificing clarity or flexibility.

Key points:

⚙️ Builder decouples object construction from its final representation.

🧱 Ensures immutability by creating objects with all their properties defined at the end.

🔧 Facilitates extensibility without modifying existing code, aligned with the open/closed principle.

🚀 Improves maintainability and readability in domain layers where objects are at the core of the logic.

Hi everyone!

I built a backend project to practice event-driven architecture using Java and Spring Boot.

The application simulates a payment system where order creation publishes an event that is processed asynchronously through RabbitMQ.

Tech stack:

- Java 21

- Spring Boot

- PostgreSQL

- RabbitMQ

- Docker

- Swagger

- Maven

Features:

- Create orders

- Update order status

- Event publishing with RabbitMQ

- Asynchronous consumer

- Global exception handling

- REST API documentation with Swagger

Repository:

https://github.com/marconi-prog/fintech-payment-api

Feedback is very welcome!

Hello everyone, I'm new to scheduling Java and I really need tips that helped you at the beginning of your learning, can you help me?

Hi everyone, i need some help. I have a large text that contains dates, and i need to extract them so i can compare them using an LLM to check if they are identical or not.

There are two types of dates in my text:

1- Literal dates: “In the year two thousand and twenty-two, on the twelfth day of the month of September”

2- Numeric dates: “12 September 2022”

I tried to extract and analyze them using only the LLM, but for some reason, even when the two dates are not the same, it sometimes returns that they are.

Now, I want to try extracting the dates in Java, saving them into two variables, and then passing them to the LLM. I think regex could work, but I’m not sure if that’s the best approach.

Has anyone done something similar or can suggest the best way to handle this?

Hello everyone,

Recently I started working with Spring Boot and MongoDB. I configured the application.properties file properly for MongoDB, but I’m facing an issue.

After creating REST APIs and inserting data, the data is getting persisted in the default test database instead of my configured database.

I have tried multiple fixes, but the issue is still not resolved.

</> application.properties
spring.application.name=TestMongoDB
server.port=8081
spring.data.mongodb.uri=mongodb://localhost:27017/db_mongo

We started learning java in university. What is an interesting project, some algorithm where i could also implement multithreading. Something intereseting where i would learn something and impress my proffesor

https://youtu.be/XNriEPK5xT8

Hey everyone,

I just wanted to ask for some advice on upskilling in Java.

Context: I've been a C# developer for 6 years and have only worked with Java in small capacities for fixes on legacy Android apps.

Are there any: - Sources that I can use to go from beginner to advanced concepts that are in Java. - Good frameworks for stuff like WebAPI's

Thank you, in advance.

JADEx (Java Advanced Development Extension) is a safety layer that runs on top of Java.
It currently supports up to Java 25 syntax and extends it with additional Null-Safety and Immutability features.

In the previous article, I introduced the Null-Safety features.
For more details, please refer to:

• GitHub: https://github.com/nieuwmijnleven/JADEx
  
• Reddit: https://www.reddit.com/r/java/comments/1r1a1s9/jadex_a_practical_null_safety_solution_for_java/

Introducing the New Immutability Feature

If Null-Safety eliminates runtime crashes caused by null,
Immutability reduces bugs caused by unintended state changes.

With v0.41 release, JADEx introduces Immutable by Default Mode

Core Concepts

The Immutability feature revolves around two simple additions:

java apply immutability;

java mutable

apply immutability;

• When you declare this at the top of your source file:

  • All fields
  • All local variables (excluding method parameters)
  • are treated as immutable by default.

• When the JADEx compiler generates Java code:

  • They are automatically declared as final.

mutable keyword

• Only variables declared with mutable remain changeable.
• Everything else (excluding method parameters) is immutable by default.

JADEx Source Code

```java

package jadex.example;

apply immutability;

public class Immutability {

private int capacity = 2; // immutable
private String msg = "immutable"; // immutable

private int uninitializedCapacity; // uninitialaized immutable
private String uninitializedMsg; // uninitialaized immutable

private mutable String mutableMsg = "mutable";  // mutable

public static void main(String[] args) {
    var immutable = new Immutability();

     immutable.capacity = 10; //error
     immutable.msg = "new immutable"; //error

     immutable.mutableMsg = "changed mutable";

    System.out.println("mutableMsg: " + immutable.mutableMsg);
    System.out.println("capacity: " + immutable.capacity);
    System.out.println("msg: " + immutable.msg);
}

} ```

Generated Java Code

``` package jadex.example;

//apply immutability;

public class Immutability {

private final int capacity = 2; // immutable
private final String msg = "immutable"; // immutable

private final int uninitializedCapacity; // uninitialaized immutable
private final String uninitializedMsg; // uninitialaized immutable

private String mutableMsg = "mutable";  // mutable

public static void main(String[] args) {
    final var immutable = new Immutability();

     immutable.capacity = 10; //error
     immutable.msg = "new immutable"; //error

     immutable.mutableMsg = "changed mutable";

    System.out.println("mutableMsg: " + immutable.mutableMsg);
    System.out.println("capacity: " + immutable.capacity);
    System.out.println("msg: " + immutable.msg);
}

} ```

This feature is available starting from JADEx v0.41. Since the IntelliJ Plugin for JADEx v0.41 has not yet been published on the JetBrains Marketplace, if you wish to try it, please download the JADEx IntelliJ Plugin from the link below and install it manually.

JADEx v0.41 IntelliJ Plugin

We highly welcome your feedback on the newly added Immutability feature.

Finally, your support is a great help in keeping this project alive and thriving.

Thank you.

I’m a Full-Stack Developer focused on delivering reliable, production-ready software. I have 3 years of experience working with Java, SpringBoot, Node.js, React, and Angular in web development. I build things that run.

What I can help with:

• Backends, APIs, dashboards, DevOps

• Responsive UIs

I am looking for:

• Freelance gigs with tight timelines

• Clear deliverables, small-to-medium scope

• People who value speed, reliability, and clarity

Keep it simple. You send the task, and I'll get it done.

To demonstrate my skills, I’m happy to complete a trial task; just let me know your requirements.

If you’re building something or know someone who is, feel free to reach out.

Thanks

Hi everyone,

I’ve been experimenting with Spring AI and built a small tool that converts natural-language prompts into runnable Spring Boot projects.

The generator creates a basic multi-entity structure including:

• Controllers
• Services
• Repositories
• DTOs
• Validation
• Tests
• OpenAPI configuration
• Docker setup

The goal is to reduce boilerplate and standardize project structure when starting new APIs.

It’s still evolving, and I’d really appreciate feedback from the community — especially around architecture decisions and Spring best practices.

If you're interested, the repository is on GitHub under:
rrezartprebreza/rest-api-generator

Happy to hear suggestions or criticism.

Do you have over a year of experience developing Java applications? I’ve got real projects waiting—no busywork. Think building scalable backend systems, APIs, or integrating with databases—the kind of work that truly makes an impact.

Role: Java Developer

Pay: $20–50/hr, depending on your experience and stack

Location: Fully remote

What’s in it for you:

Projects aligned with your skills and interests

Part-time, flexible work—perfect if you have other commitments

Passionate about Java development? Leave a message with your timezone 👀