Java Full-Stack Index Nov 2021: Back-End

Summary

• On your current project, keep your existing back-end framework unless that framework is absolutely, really not working out for you.
• If you need to switch back-end frameworks or are on a new project:
  • Use Quarkus if you need the smallest possible, fastest-starting Java application now.
  • Otherwise, use Spring Boot.

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Table Of Contents

• Summary
• Table Of Contents
• Applications
• Choices
• Popularity
  • Why Popularity - and How?
  • Google Searches
  • Students at Udemy
  • Questions at Stack Overflow
  • Job Ads at Indeed
• Analysis

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Applications

These recommendations are for building enterprise applications on PCs and mobile devices - forms, data grids, reports. They are not for games or media applications.

Choices

Here are the choices in alphabetical order:

• Dropwizard
• Oracle’s Helidon
• Eclipse Jakarta EE (was Java EE before)
• Micronaut
• Eclipse MicroProfile
• VMWare’s Spring Boot
• Red Hat’s Quarkus

Popularity

Why Popularity - and How?

Picking a popular technology makes our developer life easier: Easier to learn, easier to build, debug & deploy, easier to hire, and easier to convince teammates & bosses. Now I look at technology popularity as a funnel from interest to learning, application, and finally to skill:

• Quantity decreases in the funnel - we’re interested in many technologies, but few end up on our resumes.
• Time increases in the funnel - it takes many months, often years, for technology to move from “interest” to “skill”.

We’re interested in the trend of the ratio between competing technologies. So we use Google searches to measure interest, Udemy course buyers to measure learning, Stack Overflow questions to measure learning & application, and mentions in Indeed job ads to measure skills.

Google Searches

Google Trends demonstrates the initial interest in a technology over time. Here are all frameworks, but Helidon - Google Trends only allows five at the same time:

This link produces the chart above. This version switches in Helidon for Micronaut, and this one MicroProfile - which isn’t making a difference in the chart.

Spring Boot wins, and Jakarta EE is second. Jakarta EE’s decline in popularity here is remarkable. We can’t pick the third place in this chart, so let’s zoom in on the five challengers over the last two years:

So Quarkus is the clear leader of the challengers, with the other four battling it out for second place. This is the link for the chart.

How does Jakarta EE fare aginst Quarkus?

If current trends hold, then Quarkus could overtake Jakarta EE in about two years. Here’s the link for this chart.

Students at Udemy

Udemy is one of the biggest online learning sites. They publish the number of courses and the number of students (if it goes beyond a certain threshold). This shows how many people evaluate a technology.

That was easy: Spring Boot wins because it’s the only technology with enough students to cross Udemy’s reporting threshold.

Here are the links that show the courses for all and the number of students for some:

• Dropwizard
• Helidon
• Jakarta EE
• Micronaut
• MicroProfile
• Spring Boot:
• Quarkus

Questions at Stack Overflow

Stack Overflow Trends shows which percentage of questions at Stack Overflow has a particular technology tag. It is a proxy for using a technology during evaluation and productive use. “More questions = better” to me.

Spring Boot wins by an order of magnitude, while Quarkus places second and Jakarta EE third. Neither DropWizard, Helidon, Micronaut nor MicroProfile have a tag on Stack Overflow. This link produces the chart above.

Job Ads at Indeed

The Indeed job search is active in 63 countries representing 92% of the worldwide GDP in 2020. It demonstrates the willingness of organizations to pay for a technology - the strongest indicator of popularity in my mind. Jakarta EE is the baseline.

Spring Boot wins, Jakarta EE is second, Dropwizard third. Relatively speaking, Angular closed the gap to React a bit.

Please see here for details, caveats, and adjustments of the job ad mentions.

You can find the detailed search results with links here. They include breakdowns by continents:

Analysis

• Spring Boot dominates the Java ecosystem. So has the broadest support of libraries and third-party software working out of the box, conveniently configured the same way that Spring Boot is. Its biggest weakness is the lackluster support for creating native executables: The resulting applications use more memory and start up slower than, say, Quarkus applications, and not all of the Spring Initializer libraries work natively. We’ll have to wait for Spring Boot 3 in late 2022 at the earliest to get really competitive memory usage and start-up times. And even then, some of the Spring Initializer still may not work natively.
• Jakarta EE is a vendor-independent specification with multiple implementations. It has had a rough couple of years: First, Oracle neglected it when it was still called “Java EE”. Oracle grudgingly transferred it to the Eclipse Foundation but required renaming all packages from javax.* to jakarta.*. So even though Jakarta EE saw three releases since since 2019, I think that relatively little functionality has changed since Java EE 8 in August 2017. But the bigger issue is that Jakarta EE was designed for application server software like IBM WebSphere that host many applications on big and expensive servers. We’re rapidly moving into a world where our Java applications run as close to the metal as possible, all by themselves as microservices in small containers, or even completely serverless. This world has no place for application server software anymore. Will it have one for Jakarta EE? Only time will tell.
• MicroProfile is “Spring Boot with more Jakarta EE parts”, but without its broad support of libraries and third-party software. It started out of frustration with the slow progress of Java EE in 2016. Just like Jakarta EE, it is a vendor-independent specification with multiple implementations. It’s probably the least popular framework here, based on my measurements.
• Dropwizard is a framework that I had never heard of until it the “JRebel 2021 Java Technology Report” declared it the #2 Java framework. Its origins seem to go back to 2012. It has the most job ad mentions besides Spring Boot and Jakarta EE.
• Quarkus is Red Hat’s take on a cloud-native Java framework. “Cloud-native” means producing small and fast applications: Quarkus claims 12 MB RAM for a REST application that starts up in 0.016 seconds. It’s seems to have the most mind-share as the cloud-native Spring Boot competitor. It’s the most popular framework besides Spring Boot and Jakarta EE, except for Job ads where it trails Dropwizard.
• Micronaut is the second cloud-native Spring Boot competitor. It’s backed by consulting company Object Computing which also sponsors Grails and less popular than Quarkus.
• Helidon is the third and least popular cloud-native Spring Boot competitor. It’s an Oracle framework.

So here’s my recommendation:

• On your current project, keep your existing back-end framework unless that framework is absolutely, really not working out for you.
• If you need to switch back-end frameworks or are on a new project:
  • Use Quarkus if you need the smallest possible, fastest-starting Java application now.
  • Otherwise, use Spring Boot.