devonfw guide

With spring or quarkus you easily keep up to date with evolving technologies (microservices, reactive, NoSQL, etc.). Most application servers put you in a jail with old legacy technology. In many cases you are even forced to use a totally outdated version of java (JVM/JDK). This may even cause severe IT-Security vulnerabilities but with expensive support you might get updates. Also with leightweight open-source frameworks you need to be aware that for IT-security you need to update recently what can cost quite a lot of additional maintenance effort. However, you are able to do so and react fast to new CVEs while for application servers it typically takes 10x more time to get CVEs out of your app.

With spring-boot you can implement and especially test your individual logic very fast. Starting the app in your IDE is very easy, fast, and realistic (close to production). You can easily write JUnit tests that startup your server application to e.g. test calls to your remote services via HTTP fast and easy. Quarkus even increases this development speed. For application servers you need to bundle and deploy your app what takes more time and limits you in various ways. We are aware that this has improved in the past but also spring and quarkus continuously improve and are always way ahead in this area. Further, with spring you have your configurations bundled together with the code in version control (still with ability to handle different environments) while with application servers these are configured externally and can not be easily tested during development.

Spring and also quarkus have an extremely open and active community. There is documentation for everything available for free on the web. You will find solutions to almost any problem on platforms like stackoverflow. If you have a problem you are only a google search away from your solution. This is very much different for proprietary application server products.

Especially spring is really great for developers on exception messages. If you do something wrong you get detailed and helpful messages that guide you to the problem or even the solution. This is not as great in application servers.

Spring has evolved really awesome over time. Since its 1.0 release in 2004 spring has continuously been improved and always caught up with important trends and innovations. Even in critical situations, when the company behind it (interface21) was sold, spring went on perfectly. Quarkus on the other hand is relatively new. It does not have to carry a large legacy history and is therefore most state-of-the-art for modern projects esp. in cloud environments. JEE went through a lot of trouble and crisis. Just look at the EJB pain stories. This happened often in the past and also recent. See JEE 8 in crisis.

Spring and quarkus including their ecosystems are free and open-source. It still perfectly integrates with commercial solutions for specific needs. Most application servers are commercial and cost a lot of money. As of today the ROI for this is of question.

Quarkus is designed for cloud-native projects from the start. With spring this is also available via spring-native. Using an application server will effectively prevent you from going to the cloud smoothly.

If you go to conferences or ask developers you will see that spring or quarkus is popular and fun. If new developers are forced to use an old application server product they will be less motivated or even get frustrated. Especially in today’s agile projects this is a very important aspect. In the end you will get into trouble with maintenance on the long run if you rely on a proprietary application server.