Simon Martinelli @simas_ch Twitter profile

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Simon Martinelli

1 year

One of the most important things as a software developer is to understand the business. If you don't understand what the users want to do with your software you shouldn't write a single line of code.

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Simon Martinelli

@simas_ch

2 years

"Our application has 20 microservices". "Wow, how many developers are you?" "2" 🤯

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Simon Martinelli

@simas_ch

1 year

Most projects are not large enough for Microservices.

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Simon Martinelli

@simas_ch

5 months

OMG 😱 I feel more than honored to be part of this group of amazing people. Thanks to everyone who made this happen. It motivates me even more to share my knowledge and help many developers to be successful with Java.

Java Champions

@Java_Champions

5 months

Congratulations to new #Java Champion @simas_ch

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Simon Martinelli

@simas_ch

2 years

Just a reminder: Java enums are singletons

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Simon Martinelli

@simas_ch

4 months

I like gRPC. We are using it in a new project where the size of the message and performance are essential. Now I start to question why we use REST and not an RPC-style protocol with JSON over HTTP. RPC adds semantics to the interface.

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Simon Martinelli

@simas_ch

2 years

Just spotted it on SO: return questionsRepository .findAll() .stream() .filter(q->filter(q, embroyo)) .collect(Collectors.toList()); PLEASE learn what the where clause can do for you!

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Simon Martinelli

@simas_ch

4 years

Use @vaadin to avoid this

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Simon Martinelli

@simas_ch

5 months

Unpopular opinion: Very often Kafka could be replaced by traditional messaging.

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Simon Martinelli

@simas_ch

5 months

IntelliJ should display a warning when using Lombok Data on an Entity.

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Simon Martinelli

@simas_ch

1 year

Finally I have a working example with Angular 15, Spring 3 and JWT. I will blog about my journey next week.

GitHub - simasch/angular-springboot-demo

Contribute to simasch/angular-springboot-demo development by creating an account on GitHub.

github.com

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Simon Martinelli

@simas_ch

1 year

As a developer, going to the office is most often unnecessary. Usually, there is less communication/collaboration in the office than over Slack/Teams, but much more noise and distraction. Why do people still think that developers should work in the same room?

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Simon Martinelli

@simas_ch

5 months

I still can't believe that I'm a @Java_Champions . Thanks a lot for the apparel 🤩

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Simon Martinelli

@simas_ch

8 months

@daboigbae Code -> userId Database -> user_id

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Simon Martinelli

@simas_ch

1 year

With all the hype around Monolith, when will be the first Monolith conference?

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Simon Martinelli

@simas_ch

3 years

Goodbye Dockerfile. Say hello to mvn spring-boot:build-image Thank you @springboot

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Simon Martinelli

@simas_ch

2 months

How Netflix Really Uses Java - InfoQ. Also check out how big their Microservices are

How Netflix Really Uses Java

Paul Bakker discusses Netflix’s use of Java, emphasizing the use of microservices, RxJava, Hystrix and Spring Cloud.

www.infoq.com

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Simon Martinelli

@simas_ch

9 months

I've heard that using enums instead of boolean method parameters is better. Am I doing this right? public enum Bool { TRUE, FALSE }

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Simon Martinelli

@simas_ch

1 year

Be careful when replacing collect(Collectors.toList()) with toList() because toList returns an UnmodifiableList.

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Simon Martinelli

@simas_ch

7 months

I hate multi-module Maven projects

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Simon Martinelli

@simas_ch

2 years

When I started as a software engineer 27 years ago I had direct access to the end-user. Over the years more and more roles were added that do not add value to the solution.

Bilgin Ibryam

@bibryam

2 years

How a developer output (code) reaches the user

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Simon Martinelli

@simas_ch

11 months

Am I doing this right?

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Simon Martinelli

@simas_ch

3 months

The inconvenience of REST is that you get a 404 error regardless of whether the URL is wrong or the correct URL is called, but the resource does not exist. How do you handle that?

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Simon Martinelli

@simas_ch

2 years

All companies seem to use Kafka. I wonder what they used before Kafka, or are they just using Kafka because all companies are using Kafka?

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Simon Martinelli

@simas_ch

2 months

New developers should start in maintenance to feel the pain of fixing crappy code.

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Simon Martinelli

@simas_ch

4 years

DON'T use Lombok's @Data annotation with JPA! equals() and hashCode() will not be implemented the right way and toString() tirggers lazy loading:

The best way to implement equals, hashCode, and toString with JPA and Hibernate - Vlad Mihalcea

Bytecode enhancement and toString Last week, Mark Struberg, who is an Apache Software Foundation member and OpenJPA contributor, made the following statement: Basically, he says that implementing...

vladmihalcea.com

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Simon Martinelli

@simas_ch

4 years

Before you start learning Hibernate or any other O/R-Mapper you should learn SQL and the features of your database. Maybe you will realize that you event don't need O/R-Mapping

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Simon Martinelli

@simas_ch

2 years

Let's not fool ourselves. Small and medium businesses with applications with relatively few users do not have the same scalability requirements as Netflix or Facebook. I can't stress it enough: choose the architecture and platform based on the requirements, not the hype!

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Simon Martinelli

@simas_ch

3 months

If you hire an external consultant (like me 😅) keep this in mind 👇

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Simon Martinelli

@simas_ch

6 days

Do you really need Kafka?

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Simon Martinelli

@simas_ch

4 years

DON'T use Lombok's @Data annotation with JPA! equals() and hashCode() will not be implemented the right way and toString() tirggers lazy loading:

The best way to implement equals, hashCode, and toString with JPA and Hibernate - Vlad Mihalcea

Bytecode enhancement and toString Last week, Mark Struberg, who is an Apache Software Foundation member and OpenJPA contributor, made the following statement: Basically, he says that implementing...

vladmihalcea.com

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Simon Martinelli

@simas_ch

4 months

Hibernate is not the problem. The problem is how people use it because they don't fully understand how it works. Learn the tools you use! Don't assume how it should work check the manual and/or the source code. #learnyourtools

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Simon Martinelli

@simas_ch

3 months

Constructor make over in Java 22

Constructor Makeover in Java 22 | The IntelliJ IDEA Blog

Typically, we create alternative solutions for tasks that are necessary, but not officially permitted. For instance, executing statements before super() in a derived class constructor was not official

blog.jetbrains.com

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Simon Martinelli

@simas_ch

2 years

The best way to log SQL statements with Spring Boot Thanks to @vlad_mihalcea for sharing!

The best way to log SQL statements with Spring Boot - Vlad Mihalcea

Learn the best way to log SQL statements when using Spring Boot and why the default option should be avoided.

vladmihalcea.com

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Simon Martinelli

@simas_ch

6 months

A friend told me he doesn't take on projects that use Gradle because there is usually something wrong with the project, as developers using Gradle tend to create a custom build that only a few people understand.

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Simon Martinelli

@simas_ch

1 year

What a day! Just got an email from @spring_io : "Congratulations Simon Martinelli! Your talk, Do you really need Hibernate?, has been selected for Spring I/O 2023." I'm so excited to be part of this amazing conference again!

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Simon Martinelli

@simas_ch

3 years

If you use Lombok getter/setter why don't you use public fields? It's the same, isn't it?

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Simon Martinelli

@simas_ch

11 months

Spring Boot Application Testing and Development with Testcontainers

Spring Boot Application Testing and Development with Testcontainers | Docker

In this article, we’ll learn how Testcontainers support introduced in Spring Boot 3.1.0 simplifies testing and local development.

www.docker.com

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Simon Martinelli

@simas_ch

6 months

Spring Data JPA Repository's save method returns an entity. You should ALWAYS use that after the save call and not the entity you passed to save because internally EntityManager.merge may be called!

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Simon Martinelli

@simas_ch

3 months

What if Java developers could build web apps without touching JavaScript? 🤔

What if Java developers could build web apps without touching...

Vaadin Flow is an open-source framework for building web apps in Java. It includes a large library of UI components and offers a 100% Java API for building g...

www.youtube.com

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Simon Martinelli

@simas_ch

1 year

Spring Boot vs Quarkus

Spring Boot vs Quarkus | Baeldung

A practical comparison between Spring Boot and Quarkus, with a focus on performance.

www.baeldung.com

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Simon Martinelli

@simas_ch

3 months

I'm refactoring an Angular/Spring Boot app where front-end and back-end developers didn't talk. You wouldn't believe how much code I can delete on the client side by returning appropriate data in the API. #Fullstack #FightForSimplicity

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Simon Martinelli

@simas_ch

2 years

To all the people bashing #Log4J and arguing we should use the built-in logging off Java: keep in mind that Log4J is 20 years old. Where was Java logging then?

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Simon Martinelli

@simas_ch

7 months

If you use Lombok with Java 21 you must update to 1.18.30

[BUG] lombok 1.8.26 incompatible with JDK21 · Issue #3393 · projectlombok/lombok

Describe the bug Lombok 1.8.26 does not work with JDK21 (EA build 16) To Reproduce import lombok.Data; @Data public class Person { private String name; } $ javac -version javac 21-ea $ javac -cp lo...

github.com

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Simon Martinelli

@simas_ch

4 months

My next video will be about Spring Boot's Docker and Testcontainers support. Stay tuned!

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Simon Martinelli

@simas_ch

4 years

People on @StackOverflow don't read documentation. Most of the time I can help them by posting the right section from the docs. So today I want to thank all documentation writers! I really appreciate your work, that makes my live much easier. #RTFM

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Simon Martinelli

@simas_ch

1 year

Most applications I see have a too complicated architecture. KISS and YAGNI first, please!

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Simon Martinelli

@simas_ch

1 year

I hate this attitude that all tools, libraries and frameworks have to be free. As if the developers who demand it were working for free 🤨

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Simon Martinelli

@simas_ch

5 years

I really prefer properties file over yaml to configure @springboot . With yaml it's impossible to just copy one property by simply selecting the line.

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Simon Martinelli

@simas_ch

1 year

Spring Boot 3 comes with support for problem/json. Read the great article from @sivalabs how to use it:

Spring Boot 3 : Error Responses using Problem Details for HTTP APIs

Spring Framework 6 implemented the Problem Details for HTTP APIs specification, RFC 7807. In this article we will learn how to handle exceptions in SpringBoot 3 REST API(which uses Spring Framework...

www.sivalabs.in

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Simon Martinelli

@simas_ch

2 months

History strikes back. HTMX, and Hotwire to add dynamic behavior are getting a lot of traction lately. Something that Jakarta Faces (JSF) has already had for 15 years! AJAX was introduced in JSF 2.0 in May 2009

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Simon Martinelli

@simas_ch

3 years

A one to one mapping of entities to DTOs is an anti-pattern.

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Simon Martinelli

@simas_ch

2 years

The slides from my talk "You may not need JavaScript" at awesome #springio2022 #springio22 are online

You may not need JavaScript

Single page applications (SPA) have become the standard for web application development. Angular, React and Vue.js are the best-known. But does this client architecture fit every application? Or are...

speakerdeck.com

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Simon Martinelli

@simas_ch

3 years

If you are using Spring Data and want to know if for some condition a record exists use count instead of find. This may improve the performance because no entities are loaded and no lazy loading can be triggered.

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Simon Martinelli

@simas_ch

1 month

Working in IntelliJ without editor tabs for a few weeks. Never missed it. Give it a try:

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Simon Martinelli

@simas_ch

2 months

1 Microservice split into 15 Maven projects 🤷‍♂️

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Simon Martinelli

@simas_ch

2 years

I love my new 49" screen

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Simon Martinelli

@simas_ch

7 months

If you are a Java dev using Spring Boot and want to learn Koltin then I highly recommend the tutorial from @MarcoBehler

Spring Boot & Kotlin Tutorial - Crash Course For Java Devs

Let's write a Spring Boot application in Kotlin. We'll start from scratch with an empty skeleton project and then go about building a tiny CRUD REST service....

www.youtube.com

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Simon Martinelli

@simas_ch

4 years

Enterprise Architect, Solution Architect, Business Architect, System Architect, Software Architect, Integration Architect. And who has to do the work - the Software Engineer. We live in a strange industry.

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Simon Martinelli

@simas_ch

4 months

When using JPA/Hibernate, turn on SQL logging and watch it during development. If there are many SQL statements, you have a problem, and you must fix it! The Hibernate logger is "org.hibernate.SQL"

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Simon Martinelli

@simas_ch

3 months

It's amusing that developers can complain about a bit of XML in the Maven POM that they rarely touch but develop frontends with HTML all day long.

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Simon Martinelli

@simas_ch

2 years

When will companies understand that software developers are not resources and are therefore difficult to replace and not scalable?

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Simon Martinelli

@simas_ch

3 years

Distributed transaction patterns for microservices compared

Distributed transaction patterns for microservices compared | Red Hat Developer

As a consulting architect at Red Hat, I've had the privilege of working on legions of customer projects. Every customer brings their own challenges but I've

developers.redhat.com

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Simon Martinelli

@simas_ch

3 months

Most applications don’t need to scale because there are not millions of users

privv

@emil_priver

3 months

Why is this so accurate

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Simon Martinelli

@simas_ch

1 year

Serverless is the new mainframe. Prove me wrong.

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Simon Martinelli

@simas_ch

2 years

@sivalabs Same here. Btw. I was once asked in a job interview what my favorite pattern is. I answered: it's the pattern that best fits the problem. The interviewer didn't like my answer and finally, I didn't get the job.

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Simon Martinelli

@simas_ch

11 months

After some web app framework discussion at @spring_io with @tschuehly and @openwms I gave JSF a try (after about 10 years). What should I say? It just works. What I like about JSF is: 1. Code completion in Java IDEs 2. Component libraries like PrimeFaces 3. No need for HTMX (Ajax…

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Simon Martinelli

@simas_ch

2 years

Remember: You may not need DDD, Scrum, Microservices, K8S, Kafka, etc. The methods, processes, tools, and technology must follow the requirements. Remember: You may not need DDD, Scrum, Microservices, K8S, Kafka, etc. 🧵

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Simon Martinelli

@simas_ch

3 months

My son passed his driving test 🥳 Proud dad!

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Simon Martinelli

@simas_ch

3 years

It's funny and scary at the same time that people think that a modular monolith aka modulith is a complete new approach. This is what we've done 20 years ago...

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Simon Martinelli

@simas_ch

9 months

Great article! "I’ll always choose stability over flexibility for my build tool." That's also my reason why I never choose Gradle

Nicolas Frankel 🇺🇦🇬🇪

@nicolas_frankel

9 months

In this post, I’d like to shed some light on my stance regarding #gradle , so I can direct people to it instead of debunking the same "reasoning" repeatedly. #ant #maven #buildtools #hype #java

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Simon Martinelli

@simas_ch

29 days

Amazing! The best way to use React with a Java Backend 👇

Marcus Hellberg

@marcushellberg

29 days

Sneak peek of the next version of Hilla 🤫👀

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Simon Martinelli

@simas_ch

1 year

Separating frontend and backend by technology and/or by developers makes development slower and you produce superfluous code.

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Simon Martinelli

@simas_ch

1 year

Planning all sprints in advance, including estimation, is not agile!

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Simon Martinelli

@simas_ch

11 months

So true: "Code living on separate branches is, by definition, not integrated." That's also why I do trunk-based development. What about you?

Why I Prefer Trunk-Based Development - DZone

Explore the benefits of trunk-based development: it streamlines the development process, enhances team collaboration, improves code stability, and more.

dzone.com

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Simon Martinelli

@simas_ch

1 year

Be aware that Spring Data's PagingAndSortingRepository findAll method will execute a select plus a count query! If you have a slow query it will take twice the time!

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Simon Martinelli

@simas_ch

1 year

Up and ready for the @JavaOOQ workshop @spring_io ! But first breakfast 😅

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Simon Martinelli

@simas_ch

1 year

Instead of using multi-module Maven projects, you should consider using the new Spring Modulith project when using Spring Boot:

Spring Modulith

Level up your Java code and explore what Spring can do for you.

spring.io

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Simon Martinelli

@simas_ch

9 months

Let the journey begin...

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Simon Martinelli

@simas_ch

4 months

As a small Christmas present, I would like to give you a template for a Vaadin application with jOOQ, PostgreSQL, Testcontainers, and Flyway. It's still a work in progress, but you can check it out on GitHub. Happy Holidays, everyone! 🎁

GitHub - simasch/vaadin-jooq-template: Template Project that integrates Vaadin and jOOQ

Template Project that integrates Vaadin and jOOQ. Contribute to simasch/vaadin-jooq-template development by creating an account on GitHub.

github.com

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Simon Martinelli

@simas_ch

10 months

@NiestrojRobert I don't use Interfaces as long as I only have one implementation.

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Simon Martinelli

@simas_ch

2 months

Preparing my talk about CQRS in the small with Java Records. I love the ideas behind CQRS.

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Simon Martinelli

@simas_ch

4 months

Did you know that Spring Boot 3.1 added Docker Compose support? No!? Then checkout my new video: #springboot #docker #dockercompose

Spring Boot Docker Compose Support

In Spring Boot 3.1, Docker Compose support was added to simplify local development with external resources. In this video I show you how this works and how t...

www.youtube.com

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Simon Martinelli

@simas_ch

10 months

I don't understand the companies that want their employees to come into the office for a few days a week. Some activities work better when employees are in the same room (e.g., workshops or brainstorming sessions), but do they occur several days each week? I don't think so. Also,…

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Simon Martinelli

@simas_ch

7 days

Efficient Full-Stack Development with Java | Simon Martinelli

The talk was delivered by Simon Martinelli @ XtremeJ. More information at https://xtremej.dev/2023.

www.youtube.com

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Simon Martinelli

@simas_ch

4 months

Aaaand my customer's application runs on Java 21 in production. Just done in 2023

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Simon Martinelli

@simas_ch

1 year

As a Spring Boot user the one thing I'm jealous when comparing with Quarks is the dev mode. When will Spring Boot catch up? #springboot #quarkus

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Simon Martinelli

@simas_ch

2 years

@TNMTechnologies None. Just microservices because they think it's modern

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Simon Martinelli

@simas_ch

3 months

Just spotted in the wild 😱

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Simon Martinelli

@simas_ch

1 year

Finally, a new blog post is out: Angular 15, Spring Boot 3 and JWT with code example: #angular #springboot #jwt

Simplify Angular Authentication with Spring Boot JWT

Master JWT authentication for your Spring Boot backend and Angular frontend. This guide covers step-by-step implementation and best practices for secure, scalable user authentication.

martinelli.ch

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Simon Martinelli

@simas_ch

3 months

Did you know that you can use @testcontainers with @springboot while running your app during development? No? Then check out my new video! And don’t forget to subscribe to my channel. More interesting topics will follow soon

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Simon Martinelli

@simas_ch

2 years

Spring Boot 2.7.0 arrived!

Spring Boot 2.7.0 available now

Level up your Java code and explore what Spring can do for you.

spring.io

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Simon Martinelli

@simas_ch

1 year

I hate these mapping frameworks like MapStruct. They are superfluous if you generate the DTOs directly from the query when reading and have a command model when writing.

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Simon Martinelli

@simas_ch

10 months

That's very true 👇 Sadly

viljami.io

@anttiviljami

10 months

My problem with the software dev profession in 2023

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Simon Martinelli

@simas_ch

3 months

Migrating a project to new versions of the dependencies and suddenly, some tests no longer work. Looking at the tests, I can see that they are full of mocks and literally don't test anything. What would you do?

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Simon Martinelli

@simas_ch

3 months

Those frameworks come to my mind, when thinking about web development with Java: Vaadin, GWT, Jakarta Faces (JSF), Spring MVC with Thymelaf, Apache Wicket. What did I miss?

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Simon Martinelli

@simas_ch

3 years

Keep on mind, It's not possible to have no framework. If you don't use one you will implicitly create your own.

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Simon Martinelli

@simas_ch

11 months

Did I already say that I don't like Lombok?

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Simon Martinelli

@simas_ch

11 months

I don't dislike Hibernate - but I definitely dislike how people use it! Stop mapping all possible relationships! You don't need it because you can use JOIN ... ON ... in JPQL:

How to JOIN two Entities without Mapped Relationship - Learn to Code with Simon Martinelli

Often you don’t want to map all relationships in an entity model (a blog post about this topic in detail will follow).

martinelli.ch

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Simon Martinelli

@simas_ch

4 months

list.get(0) -> list.getFirst()

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