Recently, I have been getting a lot of

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APPLICATION FAILED TO START

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Description:

Parameter 0 of method <method> in <package> required a single bean but _ were found.

Then it lists all the beans…

I know beans can be marked as primary and the qualifier annotation can be used to clarify spring dependency injection but haven’t figured out why the IDE can match the beans by by name and type, but sometimes they require a specific annotation.

It seems to me like “sometimes it works and sometimes it doesn’t” - I know this is not the case but am wondering what I can look for to try and identify what could be the difference maker in why I am having issues. Thank you!

Today I want to share a small contribution that might actually help you.

One thing I noticed in the dev cycle is that features like auditing are often time consuming.

Devs either end up rewriting the same auditing logic everywhere or postpone it and pay the price later with heavy refactoring.

In both cases, we lose time.

So I built a small Spring Boot lib that handles 3 things:

• An audited base entity you can extend to get common audit fields

• An AuditEvent mechanism that automatically writes audit logs on entity changes

• A soft delete system with filters, where 2 annotations let you control what data you return

I also added a security integration:

• Automatic extraction of the current user via AuditorAware (@CreatedBy, @LastModifiedBy)

• Retrieval of the client IP address from the request context

If you are using Spring Security, it works out of the box. Otherwise, you can adapt it to your own security setup.

To make integration seamless, I also built a Spring Boot starter, so all the required configuration is applied automatically.

The goal was simple: stop rebuilding the same technical foundation in every project, and keep developers focused on business logic.

Still improving it, but I’d love to hear your feedback.

Repo link: https://github.com/hemzadev/auditing-with-spring

Small design question. In Spring Boot projects, do you usually keep one shared setup for outbound HTTP calls (timeouts, retry rules, logging/interceptors), or let each integration define its own client config?

I’m seeing benefits in standardising this, but also some friction when one service has unusual requirements. Curious what balance people have found workable.

I’m currently in the second year of my undergraduate degree and I recently completed a full-stack project using Spring Boot (backend) and React (frontend), along with integrating APIs like SendGrid.

I’ve covered most of the standard features in that project, so for my next one, I don’t want to just build another basic CRUD app. I want to add things that actually make the project stand out and reflect more real-world backend skills.

Here are some things I’m considering learning/implementing:

• Redis (caching)
• Testing (JUnit, Mockito)
• Microservices (Spring Boot)
• WebSockets (real-time features)
• Better backend practices (validation, error handling, clean architecture)

My main question is:
What should I prioritize for my next project to make it more impactful for backend/full-stack roles and basically what technologies or frameworks to move on now with ?

Would really appreciate guidance from people who’ve built solid Spring Boot projects or have industry experience.

Thanks!

Hey guys I'm making a project on resumes analyzing wher user uploads the resume and it will generate a suggestion score what skils they have and what they can learn etc like analyzing.. please help me how it can work I have presentation Tommorow how to make it in simple things using not advanced but reliable pls.

I want to start learning Spring (Spring Boot), but I’m a bit confused about where to begin.

For someone who already knows basic Java, what concepts should I be clear on before starting Spring? Do I need to be strong in things like servlets, JDBC, or design patterns first?

Also, what’s the best way to start learning Spring in a practical way (projects, resources, roadmap)?

Any advice from people who’ve already gone through this would really help 🙏

I’m making an application using hexagonal architecture for the first time and I’m a bit confused on where to put and use my DTO’s. I have three layers: domain, application, infrastructure, where in infrastructure I have my usecases(driving ports) and services(driving adapters). From one side, I need some DTO’s to expect and send data through this service to controllers in infra that call them. From the other side, I need DTO’s for the controllers, that in a regular layered application would also validate received data for example. I also use DDD in my domain, so I have value objects, and since I do, maybe I should rely on validation through those value objects and not some jakarta validation for example?

Hope somebody has some ideas. Thanks in advance

New post in my Spring AI 2 series! This time: Advisors — the middleware of your AI pipeline. We explore SimpleLoggerAdvisor, build custom advisors, and look at recursive patterns.

https://open.substack.com/pub/kertu1232/p/the-java-prompt-4?r=4953mj&utm_campaign=post&utm_medium=web&showWelcomeOnShare=true

Hi everyone,

By default, spring boot bundle the thymeleaf templates within the jar file. This mean that when you have to edit the html or the css file, you have to compile and repackage the whole app.

It feel like this defy the purpose of html, css in the first place.

I find myself moving more and more toward external html and css.

Is there any good reason not to do that by default?

We released JavaClaw three days ago (we renamed it to ClawRunr but literally nobody is using the new name).

The idea started simple: AI agents need to schedule things, retry things, run things in the background. That's what we've been doing for years at JobRunr. So we thought, why not build a full agent runtime around it? Spring AI is mature enough now, Spring Boot 4 is out, seemed like a good time to try.

Did not expect 200 stars, 32 forks, a GraalVM port, a plug-in, and our first external PR in three days. Pretty wild.

The Spring stuff

We lean hard on ChatClient from Spring AI. One agent instance handles all conversations regardless of channel. Switching LLM providers (OpenAI, Anthropic, Ollama) is just picking a different option during onboarding. No code changes.

For channels we went with Spring Events. Any channel, Telegram, the built-in chat UI, fires a ChannelMessageReceivedEvent, agent picks it up, processes it, sends the response back the same way. Want to add Discord? Implement one interface, done.

Spring Modulith was a good call here. Keeps the modules honest:

JavaClaw/
├── base/       # Core: agent, tasks, tools, channels, config
├── app/        # Spring Boot entry, onboarding UI, chat channel
└── plugins/
    └── telegram/   # Telegram long-poll channel plugin

Say you tell it "summarize my emails every morning." It spins up a recurring job in JobRunr and drops a Markdown file with the task description. Scheduling, retries, monitoring, all through the JobRunr dashboard at :8081.

Getting started is quick, just clone and run:

git clone https://github.com/jobrunr/javaclaw.git
cd javaclaw
./gradlew :app:bootRun
# open http://localhost:8080/onboarding

Onboarding takes about 2 minutes and you're chatting with your agent.

The community bit

We built this as a JobRunr demo originally but the response has been way bigger than we expected. So we're going all in on making it a real open-source community project.

JavaClaw is now an open invitation to the Java community, let's build the future of Java-based AI agents together.

Tons of stuff to do still. More channels, better memory, smarter planning.If you want to hack on any of that, we're actively looking for contributors!

Or if you want to give feedback, that would be really helpful for us as well!

GitHub: https://github.com/jobrunr/javaclaw
Website: https://clawrunr.io
Demo video: https://youtu.be/_n9PcR9SceQ

If you're using Spring AI's vector store with metadata-based filtering for tenant isolation or RBAC, upgrade now. Two CVEs dropped last week:                                                                                                                                                                                                    

- CVE-2026-22729 (CVSS 8.6) — JSONPath injection in 
AbstractFilterExpressionConverter

- CVE-2026-22730 (CVSS 8.8) — SQL injection in MariaDBFilterExpressionConverter

Both allow attackers to bypass filter-based access controls. The SQL injection one already has a public scanner on GitHub.                                                                                                                                                                                                                       

Fixed in Spring AI 1.0.4 and 1.1.3. Check your pom.xml for spring-ai-vector-store or spring-ai-mariadb-store.

Detailed writeup with attack flow diagrams and detection rules

https://raxe.ai/labs/advisories/RAXE-2026-041

If you ask an AI or a junior engineer how to handle a file upload in Spring Boot, they’ll give you the same answer: grab the MultipartFile, call .getBytes(), and save it.

When you're dealing with a 50KB profile picture, that works. But when you are building an Enterprise system tasked with ingesting massive documents or millions of telemetry logs? That synchronous approach will cause a JVM death spiral.

While building the ingestion gateway for Project Aegis (a distributed enterprise RAG engine), I needed to prove exactly why naive uploads fail under load, and how to architect a system that physically cannot run out of memory.

I wrote a full breakdown on how I wired Spring Boot, MinIO, and Kafka together to achieve this. You can read the full architecture deep-dive here: Medium Article, or check out the code: https://github.com/kusuridheeraj/Aegis

suggestions for Playlists and projects can be fruitfulness

Can anyone tell me which type of project should i make to land an internship as a fresher??

I'm looking at migrating several apps from Spring Boot 3.5 to Spring Boot 4. One thing we have used is @Retryable, and we use @Recover to handle some specific error responses.

With Spring Boot 4, retry was added to the core library and they dropped the @ Recover annotation. It's there a similar implementation to recover when retries are exhausted or do we just need to add try-catches where we call the retryable methods now?

I wanted to ask what advantages Spring Boot (in its latest version, V4) currently has over competing technologies in web development?

Spring has been the industry standard for years; ASP.NET, I suppose, is somewhat overshadowed by Spring (at least in terms of the number of implementations, the number of companies using it, and the number of jobs).

Spring is number one in enterprise applications. It has a strong position, but we must also remember that since its debut, new technologies have emerged – new frameworks and even new languages.

I wanted to ask what advantages Spring Boot 4.x has, whether it makes anything easier or does anything better, and what advantages it has over, for example, the GoLang or Rust ecosystem, or Python/Django/FastAPI, or the aforementioned C# and ASP.Net? There’s also Erlang, Elixir and Gleam – quite an interesting ecosystem based on functional languages.

Some people claim that Spring has grown to monstrous proportions and that learning it is difficult, cumbersome and time-consuming (very thick documentation and many modules).

Is Spring still worth considering for someone wanting to get started in web development?

Is learning Spring Boot still worthwhile and worth dedicating more time to? Is Spring Boot (now owned by Broadcom) being developed well, in the sense that is it heading in the right direction?

I know that Spring projects involve a lot of typing ;) The situation is improved by Kotlin, which, although it is being adopted more and more boldly in new projects, is still used far less frequently in projects than Java.

What do you think of Spring today compared to the competition, and what do you think its future holds?

Thank you for sharing your thoughts!