Which version of JDK should I use?
whichjdk.com
whichjdk.com
I feel like the actual decision process is fairly straightforward in nearly all cases:
- Use whatever vendor happens to be most convenient to install. If nearly everyone using your OS is installing Java one way, and you're installing it some other unusual way, you should be crystal clear about why exactly you need to do that.
- Generally go with JDK 11, if you may have to deal with older software then maybe go with 8, if you want the shiny new stuff and don't mind some extra hassle then go with JDK 17 (it's not well-supported by everything yet).
That's pretty much it. There are exceedingly few cases where it actually matters whether you installed Corretto or Oracle OpenJDK, and in those cases you'll likely end up either testing all the JDKs anyway to make your decision or writing your own patches for whatever you need.
Presumably this has to do with support and possible testing. People buy RedHat EL for the longterm support, if they use a different vendor for the JDK they have to set up a whole new contract for that with a different company. By contrast, people using a free Linux distro may not have any benefit to using RedHat's JDK.
You will get a l2 sysAdmin or an intermediate developer. If for some reason the root cause is nailed to a reproducible bug then it will go into the bug tracker
Personal experience, some very nice bright people there but also work for a company
Yes -- do what everyone else does.
> Generally go with JDK 11
Seconded.
User rococode is dead on correct here.
To me it sounds reasonable that Microsoft tests/optimizes their JDK better for Azure, and Amazon -- for AWS.
That's a good recommendation for library authors, but if you're deploying an application that's regularly maintained, I would recommend using the most recent version -- that's the cheapest, safest way -- and if it isn't, consider an old version (like 11) with one of the LTS offerings, choosing a vendor you trust to support OpenJDK (https://news.ycombinator.com/item?id=28821316).
Of course, new applications should now target 17. It's both the current version and it has LTS.
If you're using the current JDK version (recommended for regularly maintained applications), it doesn't matter which distribution you choose, as they're all pretty much identical. If you're using an old version (LTS, intended for legacy applications, which might benefit from it), pick a vendor you trust for OpenJDK support, as the builds are not the same, and neither is the support. After Oracle, which contributes about 90% of the work on OpenJDK, the companies distributing builds that contribute to the project and have experience with it are (in rough order of experience and/or contribution): Red Hat, SAP, Azul, Bellsoft, and, more recently, Amazon, and Microsoft.
There are, however, a couple of standouts: Alibaba's Dragonwell, which, last I looked, did not meet the Java specification, and Eclipse Adoptium, built by IBM, which is the only distribution built by a team that isn't involved with the OpenJDK project, isn't very familiar with it, and isn't a member of the OpenJDK Vulnerability team, and so get security patches only after the other vendors have delivered their builds.
LTS is associated not with version number but with vendor that provides JDK. So if you don't pay any vendor then you don't have LTS, you just have a number and hope it is in some way better thant any other number - which is not.
OpenJDK has no notion of LTS, they release new versions every 6 months, vendors decide which one of those will be supported with fixes, e.g. Azul decided that their JDK 13 and JDK 15 will be supported with fixes for longer their JDK 12 and 14.
I develop on arch and they have a great jdk system as well.
Wasn't AdoptOpenJDK the "legit" recommendation a couple years ago? I only heard about all of these other versions sometime later. (Looking again, it looks like the Oracle OpenJDK is shipped in Ubuntu's repos, so maybe I was mistaken).
It was the recommended choice by random internet users who posted blogs, just as is this website, a random website by some random person.
The best way for you to understand which JDK to use is to understand superficially what is involved with the source code and the build process between vendors, and their licenses.
Source code starts out the exact same, that's why they are all OpenJDK, because they take the source code from the OpenJDK public repository's main branch.
From that point on, they can choose to apply source code patches from OpenJDK that have not yet been merged into the main branch, or they could apply their own source code patches. Those patches often will be security fixes, or backported features. Here you have to understand that there is only one main branch of Java. So if you want security fixes or new features but are still on say Java 8, someone has to pull the old commit that was tagged Java 8 and selectively cherry pick a bunch of commits afterwards to apply over it that retrofits all security fixes and possibly a few select new features (like say some performance improvements patches). And if you've ever had to do a cherry pick merge on old code, you know it can be tricky and sometimes there are conflicts and maybe you even need to manually resolve them.
And even if they are not grabbing the source from an older tagged version commit, but are grabbing it from the latest tagged commit (so as of this writing Java 17), well it might already be that there are some newer commits that fixed some security bug, or other bug, or improved performance or startup, etc. So in their build of Java 17 they could even decide to apply some of those patches that happened after to the Java 17 latest release. And they might even choose to apply some patches that haven't even made it to the main branch yet, so maybe still have an open PR, or they are the ones patching something of their own.
After having grabbed the main source of OpenJDK, and potentially applied some patches to it, they proceed to build it for one or more platforms.
In the process of building, they will choose which platform to build for, such as Windows, Linux, MacOS, x64, ARM64, x86, etc. And they will choose what to include in the build, for example should you bundle Java Mission Control, javafxpackager, jarsigner, jstatd, visualvm, etc.
Finally they can choose to tests each build on each platform they built it for by running the full test suites, but they could also only partially test, as in, run only a subset of the tests, or tests only a subset of the platforms they built it for.
You'd want to run tests especially if you did patch the source, to make sure none of your patches introduced bugs, but the build could also have created an issue which tests could uncover, like forgotten to include some important C lib, or resource, or built with wrong optimization options, etc.
And last but not least, the license they choose. There's two parts here, the first one is that if they made any changes to the source of their own, their changes might be on their own license, or might not even be open source. That means you might not be able to fork the exact source they used for your own needs, or even get to see the full source they used. The second are the terms of use for each things bundled in the build. Do they let you use the JRE for cloud applications? Can you redistribute it to others? Can you use it for commercial work, etc.
Hopefully that better equips you to understand. Most of the companies who make money by building OpenJDK and offering support will probably do a good job at making sure that they backport security fixes as soon as possible, and make sure to always test everything to be sure their backport and custom patches didn't break anything, but they might not always do so for your chosen platform. But as any company who wants to make money, they need to have some of their customers pay them at some point, and that's where licensing and terms of use come in, but more and more they go full open source on their source patches and customization, allow anyone to use things for free in all settings, but offer paid support, though to be sure read their license and terms of use.
And if you can't be bothered to read their license or terms of use, that's why people have been recommending AdoptOpenJDK which is now Eclipse Adoptium. Since they're a community effort managed by a non-profit, you can be more confident that their license and terms will be and remain fully open source and free to use in all cases. The downside is that it's a community effort, you don't know if they'll apply security patches quickly, or fully test, etc. And if there's any issue with the build you encounter, there's no real support, no SLA for it, etc.
P.S.: There also exists some alternate JDKs, that are not based from the OpenJDK's main source branch, such as OpenJ9, GraalVM, Zing, JamaicaVM, etc. Those should be considered as alternate implementation of Java, they often have very different runtimes and garbage collector and all that, though they can still partially be using some of the stuff from the OpenJDK as well. While all the OpenJDK builds I was talking before always implement everything using the OpenJDK source, all they'd do is add security fixes, bug fixes, retrofit some newer features into older releases, etc. They wouldn't provide alternate implementation of anything the way that GraalVM or OpenJ9, et all, will do.
Any reasons they are not a member? I would think IBM is trustworthy and mature enough to deal with sensitive security issues.
Unless you want serious long term pain then you shouldn’t be more than one LTS release behind. So if you are not running on JDK 11 or later you should be strongly thinking about upgrading.
Upgrades now are pretty straightforward if you are past JKD 9 - with JDK 16-17 being a bit tricky, but less than JDK 9.
Source?
In other words, OpenJDK does not follow any LTS/non-LTS release cycle. Hence there is nothing special about Java 17 vs 16 when it comes to stability.
Using so called LTS without paying for it is in no way different from using latest. You get similarly tested software and no one to call if you need a security fix asap.
That depends. If most people follow the advice of "sticking to LTS", these versions will have way more users, and thus will be more "battle-tested", as in tested in production.
There haven't been any notable language features added since java 9 besides some basic syntax sugar (which is already covered by stuff like lombok anyway).
For features and performance you might as well just target .NET 6. It has things that have been perpetually 'too hard to implement' (read: oracle doesn't want to pay their engineers to impl it and will sue you if you do it yourself) like value types, generics without type erasure, no checked exceptions, etc. and with .NET 6 performance is better than OpenJDK across the board.
.NET 6 is vastly more performant than .NET 5, which was already faster than openjdk and openj9 (https://devblogs.microsoft.com/dotnet/performance-improvemen...)
> and also what do you mean by oracle suing if you implement value types?
this one shouldn't need an explanation, oracle very commonly pursues frivolous lawsuits as a way of bullying money out of businesses that don't have the budget to fight them for years in various courts.
I do find people comparing Java and .NET Core often are compare apples to oranges however. Working on both languages it is just my opinion but the .NET platform is newer - it has a better "base" even without the same man hours. Much of the engineering time in both ecosystems is spent optimising for code typical to that ecosystem which is affected by history/legacy like any other software system.
The previous versions in this stream (.NET Core 2.1, .NET Core 3.0 and 3.1) also run fine on Linux. For web server / API server workloads, it's been stable for a lot longer than 11 months, and people do indeed "bet the farm" or "run the business" on it, quite happily.
Technically, this starts with .NET core 2.1 on 2018-05-30. The prior version, 2.0, released on 2017-08-14, wasn't _quite_ there yet although some people were happy with it for production use.
.NET Core 2.0 (August 2017) we assume.
Have you even seen the benchmarks compared to Java and other languages?
https://www.techempower.com/benchmarks/#section=data-r20&hw=...
If you're not paying attention to .NET its time to get your head out of the sand, seriously.
"no real reason" is a stupid take. I could list multiple, but a big one is that there are hundred java developers for each dotnet developer in my city. The java env is well tested and well understood, if anything one should argue why not use it instead of a hip and trendy alternative.
In what way? It's slower and has less features than the .NET runtime.
> "no real reason" is a stupid take. I could list multiple, but a big one is that there are hundred java developers for each dotnet developer in my city. The java env is well tested and well understood, if anything one should argue why not use it instead of a hip and trendy alternative.
So, your only credible excuse for using java is inertia from boomers and middle managers refusing to adapt from the standard of the early and mid 2000s?
If you come in and freely migrate all of the Java codebases to .NET while maintaining code quality and functionalities, I'm sure many people would let you do it. If you don't understand why people stick to one language, that means that you've never worked on a big codebase, or completly ignore the business side of the developer job. In both cases, that's a lack of wisdom on your part.
Perhaps not solved, but at least partially addressed with value classes[1] and reified type parameters[2].
[1] https://kotlinlang.org/docs/inline-classes.html
[2] https://kotlinlang.org/docs/inline-functions.html#reified-ty...
pretty odd take, in which country?
Lots of people use .NET in enterprise, I don't know where you got that impression.
Regardless, i actually compared Java with .NET and their web frameworks as a part of my bachelors', everything from synthetic benchmarks for encryption and data processing and transformations, to things like shuffling JSON around. Now, it's all in Latvian and was a number of years ago, so it's not entirely relevant at this point, but i did have some tangible findings.
In short:
- both Java and .NET (then Core) are inconsistent in their performance - there are certain things which are slower in one technology than other by not using external optimized libraries. For example, Java had problems with writing deeply nested dynamically generated JSON with JavaEE libraries (now Jakarta), whereas .NET Core had problems with handling large amounts of text
- their performance was largely comparable in most other tests, neither was faster by a factor of 10, like you'd see with Python and Ruby compared to either
- thus, it's largely a matter of choosing the actual frameworks that you'll want to utilize properly and consider both the job market and business factors (familiarity with the tech stack, job market etc.)
- in summary, they're close enough for it to not be a technical decision most of the time in real world circumstances (save for a few exceptions), but rather is a decision that depends on social elements
- i don't believe that the observation of them being "close enough" has changed much, both in legacy code and otherwise
- .NET Core and now .NET 6 has improved bunches with its runtime; Core was so successful it's essentially the future of the platform (i feel bad for developers who'll be tricked into working on legacy code with the old .NET and IIS, versus the new one and Kestrel)
- JDK has improved bunches with its runtime and GC; the runtime situation is a bit complicated and cumbersome, considering the OP's article, but overall it's pretty usable, especially with frameworks like Quarkus
If you jump around the different tabs that compare which frameworks do what better, on average:
- .NET is better for plain text
- .NET is noticeably better for data updates
- Java is noticeably better for JSON serialization
- Java is noticeably better for single DB queries
- Java is noticeably better for multiple DB queries
- as for cached queries and other use cases, there's more variance
- neither is better than the other for it to matter a lot
In short, you're not necessarily wrong - there have indeed been great improvements to the .NET platform and it's good to see it finally being a capable and performant tech stack that you can use on *nix. But you're also not right: Java is getting similar attention, even though it's still lagging behind a few years in regards to "having its stuff together" (e.g. going from Oracle JDK to a more stable model + the JDK 8 to newer version shift, which is similarly painful with old .NET versions).
To lighten the mood, i'd consider suggesting that anyone also have a look at Go, which is similarly performant and allows you to build runtime independent executables by default, which is easier than in either .NET or Java. It's also pretty easy to write and has seen good use for the development of tools, since its startup time is a tad better than either that of Java or .NET as well. Here's the three compared: https://www.techempower.com/benchmarks/#section=data-r20&hw=...
All of this is currently being implemented in project Valhalla...
It's comparing apples to oranges - in this case .NET is also being actively worked on so may have other things by then. Compare current state only.
The truth is each platform has prioritized features relevant to its context. For what its worth in my experience while the JVM has many more JIT optimisations and the like it tends to need them more of them given the lack of some of those features you mention (e.g. value types). Whereas .NET code allows value types, better management of memory (i.e. Span), reified generics etc so the focus has been to allow the user to optimise themselves where required where still allowing for a decent performance default. Many of the optimisations in the JVM wouldn't have the same bang for buck in .NET and vice versa.
On a personal note I'm more of a fan of the .NET philosophy because the code is usually fast enough, and when I need to tune memory, avoid allocations, and do fast code it seems to offer more tools not in an unsafe context to do so. It allows a better "upper bound" of performance for core things IMO while keeping to bytecode/IL. Many benchmarks where the same level of application optimisation has occured from what I seen have confirmed this bias for me. YMMV
You could call `+` syntatic sugar, just like anything past assembler being that.
None of those are features, they were desperately needed shorthands for common java idioms. This is like calling braceless if/for/while statements 'features', when they're purely syntax sugar that has fallen out of favor completely because there's been several major security vulns found in major projects due to their use and development oversight/code review failure (https://nakedsecurity.sophos.com/2014/02/24/anatomy-of-a-got...), to the point where most companies ban writing them.
Just off the top of my head:
* LINQ. Added to C# in 2007, Java didn't get streams until 2014.
* structs/value types, implemented in net framework and net core for 15+ years, but not present in java 17. Some oracle engineers have been working to implement them under project valhalla but it seems to be vaporware at this point after 8+ years of work.
* unsigned types, no plans to implement in java (though IIRC it was originally planned as part of valhalla)
* async/await
At the feature level Java is stuck in the mid 2000s. Nobody wants to do the actual work on keeping it competitive.
Thank God they didn't shove this crap in. When Loom ships (I believe the next LTS is their target, more or less), JVM will have the same concurrency story as Go does, without blue/green function split like in C#.
Not too comfortable to use functions that will compile to efficient byte code exists for them, but with the definitely coming Valhalla, it will be trivial to create a custom primitive class for unsigned ints.
> async/await
With project Loom, it will avoid the mistake of function coloring that async introduces. In a managed language, why not let the runtime automatically transform blocking calls to non-blocking, when it already knows what’s up?
Not saying it's a good or bad thing, but .NET and C# by extension has had these features for years (decades in some cases) while the only thing java has are half-baked prototypes and plans to 'maybe' implement things. In many cases these plans just get endlessly pushed back and new java major versions just become a pile of simple bugfixes which in the past were just pushed as minor jre updates.
In the background, coroutines are a strictly less useful feature than what will happen with Loom, and please show me any “promised feature” that were only half-baked prototypes? We do have one half of Valhalla (vector api) under an experimental flag with JDK 17 already, several language related JEPs were shipped already. That Loom and primitive classes take their time only mean that they are not vaporware, because these are actually ridiculously complex problems.
Streams are a library feature, records are a language feature. Streams could be implemented outside, records could not (no lombok abominations are not records).
comparing braces to records/multi line strings/switch expressions is so funny that I won't even comment on that.
Also, Oracle does pay plenty for the development of Java, and is a (surprisingly) good steward of the language, let’s drop all the blind hate.
And both in terms of GC and JIT, the JVM ecosystem is ahead, the reason they can be so head-to-head is that the CLR doesn’t hide lower level controls all that much, allowing for better hand-tuned programs (at the price of the resulting code not getting “automatically” faster in a possible future release)
In some cases, this may be your ops team.
Support for vulnerability patches, stability, and so on. You can automatically update and maybe that goes well and maybe problems are caught in testing. Regardless those events and changes have over time have increased costs. LTS should mean lower costs both through increased support focus, increased population of active users, and reduced forced change.
You're not wrong...
And many companies are cheap and don't buy - hence using JDK 17 won't give you LTS, buying support gives you LTS.
Non-LTS JDK doesn't have anything after 6 months.
And BTW. Azul MTS want's to have a word with you: https://www.azul.com/products/azul-support-roadmap/
e.g. JDK 13 and 15 do get builds.
They are in there but easy to miss - Bellsoft actually have builds for both jdks and jres for more than mainstream x86_64. Termurin dont even have jres anymore (last time I checked)
Nowadays no one keeps just one JRE in their laptop/desktop and disk sizes are in TBs so no point in saving 100 MB and lacking development tools.
And in one targets containers or systems with small amount of disk jlink give more gains than JRE.
Java has been "breaking changes" between releases to make python blush for a few years now, 17 finally looks like a worthy migration from 8.
323M jdk
136M jre
If you want jdk you don't use jlink.
didn't say it was? A java.base jre is about 40mb extracted jdks extract to about 400mb (depending on os/arch)
A downloaded then extracted jdk will take over 500mb of disk space
Sometimes you're creating an app that other users need to run in their own environments - and in that case, targeting "latest LTS" is safer, as they may have requirements on what they can run that you don't.
Because now the feature releases can add new APIs rather than just new JVM features as they did under the old model, this process can be slightly more work, but still significantly less work over time. As regularly maintained applications update code and dependencies regularly, anyway, this is a clear win. Not only is the upgrade process easier and cheaper, but you get to enjoy the regular and significant performance improvements that have always been part of the six-monthly feature releases, but aren't in the LTS patches.
[1]: Those feature releases under the old model also added major new features with significant changes to the VM. For example, the G1 GC and JFR were added in feature releases.
My point is that migrating to new releases isn't always trivial, especially the more complicated and complex a project gets. If i knew that i'll run if compiled successfully, then it wouldn't be too bad, but with the amount of reflection, dynamic class loading etc. that frameworks like Spring favor, my workflow to date has been fixing a bug, building and running, something else breaking, fixing that bug, building and running, something else breaking, realizing that i cannot fix this because upgrades to the logic would be inherently "lossy" due to a mismatch of what the new framework versions provide, making it so that breakages that aren't covered by tests will also be created and so on ad infinitum.
Sometimes it makes me wonder why JDK 9 onward just didn't have a compatibility module: "Here, install this to have all of the old Java classes that were removed from the standard library after JDK 8 and retain that old functionality for software projects that would otherwise be stuck in development hell short of a full rewrite." Or something like that for Spring Boot, that lets you use web.xml instead of having to use hacks to load its contents and register all of the servlets, with half of them not working anyways, because some class names were changed along the way.
Software doesn't always age beautifully.
Furthermore, it feels like new runtime and package versions are made in ways that accidentally break backwards compatibility with no clear ways to avoid this.
Mind you; you usually end up with the services all in different states of node/jdk/etc versioning(at least the companies I worked at).
Here's a list of the things that were available in JDK 8 and no longer are: https://advancedweb.hu/a-categorized-list-of-all-java-and-jv...
When you stumble upon something like that, at best you can import a Maven dependency with a version that has what you need, at worst you need to rewrite the code to use another library or set of libraries.
If you have any low level logic like custom class loaders written against older JDK versions (think before 8), then they'll be forwards compatible until 8 for the most part, but will break afterwards. Coincidentally, reading code that deals with low level logic is also not easy to do, especially if it's not commented well.
If you rely upon reflection, or use advanced language features (like the JasperReports framework for generating PDFs, which also has a build step for building the reports), in some cases things might compile but not work at runtime due to class mismatches.
Many frameworks need new major versions to support newer releases than JDK 8, for example Spring Boot 1.5 needs to be upgraded, so you're also dealing with all the changes that are encapsulated by your dependencies. In another project that i also migrated, needed to rewrite a lot of web initialization code for Spring Boot 2.X.
Not only that, but with those framework changes, certain things can break in the actual environments. For example, if you package your app as a far .jar, then you'll no longer be able to serve JSP files out of it. It makes no sense, but packaging it as a .war which can be executed with "java -jar your-app.war" will work for some reason.
I some other libraries, method names remain the same, but signatures change, or sometimes things just get deprecated and removed - you have to deal with all of that, which is especially unfun in code that isn't commented but that the business depends on to work correctly. Throw in external factors such as insufficient coverage of tests and you're in for an interesting time. I'm not saying that it's a type of environment that should be condoned, but it's the objective reality in many software projects.
Oh and i hope that you're also okay with updating all of your app servers (like Tomcat) or JDK installs on the server as well, especially if you depend on some of the Tomcat libraries to be provided and for your frameworks/libraries that depend on them being present at runtime to accept those new versions effortlessly. It all feels very brittle at times.
This is especially a nightmare if your servers were configured manually - personally i'm introducing Ansible and containers to at least isolate the damage of Ops rot, but it's been an uphill battle since day 1.
Here's an exceedingly stupid one: sometimes there are checks in code to make sure that you're using the right version of JDK (or even the Oracle JDK), which get confused with the larger versions. It's easy to fix when it's your code, but really annoying when it's external tools - personal nitpick.
Addendum: here's something that i expected to break, but didn't. We use myBatis as an ORM. It has XML mapper files that define how to map entities and construct queries against the DB based on that. Also, it uses Java interfaces and dynamically calls the underlying XML code as necessary. So essentially you have an interface, which has a corresponding XML file in which you have quasi-Java code (e.g. checking what parameters are passed in to the query) that's used alongside a number of tags to dynamically build SQL queries. Here's an example: https://mybatis.org/mybatis-3/dynamic-sql.html
Instead of something breaking in myBatis, what broke actually was Hibernate in the newer versions of Spring. Oh, and Flyway for DB migrations simply used to work with a particular Oracle DB version as well.
This silently broke a bunch of scripts and callbacks because of class cast exceptions and such. The solution was to rewrite the scripts in such a way to import the Java Long class and use that directly to express large integers.
The most important breaking issues I've found were not necessarily in our code base, but in dependencies. Libraries that include libraries that include libraries, all doing their own thing, a lot of the time involving some pretty scary reflection stuff for some unexplained reason. Blindly upgrading libraries only gets you so far, sometimes a dependency gets abandoned and you need to find a replacement and rewrite your code to call the APIs in the right manner to be backwards compatible enough.
This is where it always seems to end up. Why do people bend over so far backwards doing reflection that isn't specified?
Either because there's no other way to do it, or because the official way is too slow.
(I always found this really frustrating when making the argument for Scala. Yes, Scala-the-language is more complex than Java-the-language. But it's not more complex than the pile of reflection magic that anyone who tries to write a nontrivial system in Java actually ends up using).
All that said - for the 'normal' Springboot applications, we saw almost a 25% performance jump for the same code - updated libraries - running on K8. Java 11 was a substantial performance improvement. The jump for us to Java 17 will happen this winter, and looks to be a non-issue so far.
In some ways, this is just a consequence of a kind of evolutionary leap forward for many applications. We don’t deploy our WARs into application servers anymore, we try to pack a fat JAR, or maybe even a statically linked runtime, into a container. We rebuild the whole world on CI all the time. I mean, Java 8 has issues just respecting cgroup limits, which many a despondent ops engineer has discovered.
I think there’s still room for the 1M SLoC monolith even in this new world, but there are real benefits on the horizon for upgrading to Java 17 and beyond. We’ve reached a point where it’s just more expensive not to make upgrades a regular part of you development cycle. And, no one is stopping you from just staying on 1.8. I mean, I’m sure there are still decaying enterprises stranded on 1.3.
Sadly, i don't get that choice, nor do i get the choice to make the judgement call to leave the monolith on JDK 8 in the name of stability. But hey, at least i'm paid a bit of money for it, so i have some motivation to work on all of it to the best of my abilities, learn a bit more about the JDK internals, have a word or two to tell others about my experience before i inevitably burn out from the churn.
Personally, i do still think that Java is pretty good when it comes to stability and backwards and forwards compatibility, especially since tooling like Maven is actually pretty good when compared to the alternatives (well, the parent POM functionality is confusing sometimes, but oh well, it has its use cases). That said, JDK 8 to newer releases was indeed a generational shift (probably one for the better) and you see similar things with Spring Boot 1.5 to Spring Boot 2.X, those breaking releases are inevitable.
I only wish that the things blocking people from writing more modular systems would disappear over time, so that huge monoliths that are incredibly hard to work with wouldn't be such an issue. I'm not necessarily advocating for microservices here, since people tend to go straight from one ditch into the opposite one (multiple services per person, nightmarish service mesh, needlessly large % of the code being for shuffling data around, suddenly building a distributed system even within a single domain), but at the very least it would be really nice to have someone look at it and say: "Hey, this PDF generation logic looks really brittle and perhaps should be a service of its own." or maybe: "Oh, hey, we're serving our RESTful API calls and front end resources from the same application, maybe we should have a separate front end app, served through a regular web server?"
Then again, if nothing else, i always have the choice to choose where i'm employed, even though i don't feel like letting my coworkers down at the moment either.
I'm in the middle of a migration to 11 and my general approach has been to get it compiling on 11 while targeting 8 with (--release 8). That seems to catch a great many things that would otherwise fail. The hardest part thus far was figuring out the appropriate libs to replace Java 8 ee stuff, mostly wrt soap and xml. I'm hoping moving to 11 goes smoothly but we'll see. I'm hoping to have the artifacts to a point where they can run on either 8 or 11 without issues.
I don't know PrimeFaces, but I have worked with JSP, which does have a flag to set the compiler version (in case you were ever thinking about putting java lambda's in JSP files, which is possible but not recommended due to mixing code).
The hardest part of upgrading the JDK is going from 8 to 9. After 9 it is much more forgivable. As for Spring, major versions are a pain, as is Hibernate. The other parts of Spring are generally well upgradable if you read the Spring changelogs.
https://projects.eclipse.org/projects/adoptium
> The mission of the Eclipse Adoptium Top-Level Project is to produce high-quality runtimes and associated technology for use within the Java ecosystem. We achieve this through a set of Projects under the Adoptium PMC and a close working partnership with external projects, most notably OpenJDK for providing the Java SE runtime implementation. Our goal is to meet the needs of both the Eclipse community and broader runtime users by providing a comprehensive set of technologies around runtimes for Java applications that operate alongside existing standards, infrastructures, and cloud platforms.
Under Adoption, there is:
* Eclipse Adoption Incubator
* Eclipse AQAvit
* Eclipse Mission Control
* Eclipse Temurin Compliance
* Eclipse Temurin
But yea... the name is awkward.
Eclipse Temurin 17 or Temurin JDK 17 should be sufficient.
Why didn't they just keep AdoptOpenJDK? That was a good name IMO.
> Along with the move to the Eclipse Foundation, the project has a new name: Eclipse Adoptium. The move and name change are being made to ensure vendor independence and long-term viability of the project. As you know, the Eclipse Foundation has a number of key projects, such as Jakarta EE, under its umbrella, with the foundation providing the necessary legal and operational support for its projects.
I suspect that part of this is that it has more to it than just the JDK.
Hi, I just want to expand on this a bit...
The "eclipse foundation" is actually not just sponsored by IBM. Nor is the IDE. As for what support it provides, that's actually spot on and is under a similar idea to what apache and linux provide. There are of course differences: but for most people the vague idea that open source foundations exist and provide some similar functions as a way to host projects is enough for this discussion
A lot of eclipse's revenue actually comes from working groups with Jakarta EE being the biggest one. There are also IOT, Automotive and many other working groups + projects under the eclipse umbrella.
A section called "For production use this" or "if you don't know what you're looking for, use this". And "this" can be a particular version (Ubuntu 20.04.6) or a rule of thumb (for production, always use x.y.1 version or above).
Or it can be a table like this one. Django is, as it is in many fields, the gold standard in this regard.
It gets confusing sometimes. Yesterday I was trying to update the python version of one of my applications and was wondering; should I do it now, or do I need to wait for 3.10.1? I did it anyway because the app barely gets traffic anyway, but more clarity is always welcome.
Since then, Oracle completely open-sourced the JDK and the associated tools and gave the the compatibility kits to the community to use. The result is that there are now several different distributions of the JDK. This is undeniably a good thing.
As to the 6-month release cycle, it allows the community to get new features on a much faster cadence than any of the other major languages. If it's too fast for your preferred way of doing things, stick with the LTS releases, which come out on a three-year cycle and include all the features from the prior releases.
There might be reasons not to like Oracle, but their stewardship of Java has been pretty good.
Sun went several years without releasing a new major version, but that same page lists frequent minor updates. So yes, I would call that exactly a stability to treasure.
The only difference appears after 6 months after release - if you don't want to upgrade (you should) you have to find vendor that will sell you support for given release.
E.g. Azul provides it for 11, 13, 15, 17. Oracle for 11 and 17.
Adoptium provides builds (not LTS) from 11 and 17 branches, where some vendors push their bugfixes. So it is like a semi-LTS, they won't fix your bugs, but if someone fixed a bug it most likely will end up on that branch.
I think the situation is much better now than it was. The daft renaming of AdoptOpenJDK is the only recent low point.
If there is a bug/performance issue that only happens in the context of AWS, then Corretto would be the most likely to rapidly patch the issue as it impacts their customer base. Potentially patches for those sorts of issues would be discovered by AWS through their own use and testing.
Likewise for the other vendors and their own platforms.
https://docs.gradle.org/current/userguide/compatibility.html
If you switch your Gradle buildscript files over to being written in Kotlin, the problem goes away, as Kotlin's runtime doesn't seem to use any similar explicit checks.
(Doing so also allows you to go further and test out EA JVM builds, e.g. Project Loom, which Groovy-based buildscripts have never been, and will never be, happy with.)
Gradle itself isn't written in Groovy; it's 5% Java, 95% Kotlin. The Groovy runtime is only spun up to compile and run Groovy buildscripts (i.e. the default kind of Gradle buildscript with a ".gradle" file extension.) If none of your buildscripts are written in Groovy, then you're not compiling or running any Groovy code, so that runtime check never executes.
This doesn't appear to be true just by looking at the Gradle GitHub repository. It claims that the code in the repo is 46% Groovy, 44% Java and 6% Kotlin
All of this is unnecessarily complicated and confusing, as a developer it really feels like they don't want me to use Java.
I have the feeling that, similarly to what happened with the Roman empire, greed, laziness and burocracy are going to drag everything down.
You have official Oracle JDK build.
You have official Oracle OpenJDK build.
You have plenty of alternative builds.
It's like kernel.org Linux, Debian Linux, Fedora Linux and so on. Does it hurt Linux? I don't think so.
All builds should be perfectly compatible between each other.
Simplest way is just use Oracle JDK 17. It's LTS, free and official.
There's an Oracle jdk whose usage terms need to be deciphered using a lawyer to understand precisely when and how you can use it. So much that the average advice is to not use it. Like if they told you "hey, node.js is cool but don't use the one from those who maintain and develop the code". This would be a huge red flag for any other language than Java, which can leverage 30 years of sunk costs for companies that now will not switch lightly to something else.
The alternative builds are good, yet not official and they might introduce thin incompatibilities or different behaviors. They should not but this whole article suggests that they actually do.
The simple existence of articles like this one testifies that this is a mess for a lot of people.
Ignore oracle jdk, ignore any concept of LTS/not-LTS, that's only for companies with big pockets and specific needs.
People really like to make it sound more complicated than it actually is.
You get mystery bits that haven't been put through the TCK.
Though, I might be missing some important details, and I would love to understand it better.
Edit: a sibling comment suggested that now there's a package repository for that, and indeed there is.
If anybody's interested:
sudo add-apt-repository ppa:linuxuprising/java
sudo apt-get update
sudo apt-get install oracle-java17-installer oracle-java17-set-defaultHowever, you don't need a special repo for getting OpenJDK 17. Yours is for getting Oracle JDK 17, right?
With SDKMan switching between JDKs is painless, despite the install method of SDKMan itself being one of those.
But it's not just Java. To build our frontend webapp I need NodeJS, and there too some specific version depending on the version of the webapp or just because we've updated.
I'd love to be able to just apt install all of this, but the downsides are just too many.
On the other hand, i only use standard packages through apt/yum/apk/whatever for server software, a distinction that's lost too often in my opinion. Everything that the server needs to operate should have automatic (at least security) updates enabled and ideally the configuration should be fully automated through Ansible with something like GitOps and read only access through SSH (with fallback account with write access for special cases) for maximum auditability and being sure that this is less likely to happen: https://dougseven.com/2014/04/17/knightmare-a-devops-caution...
Furthermore, the servers themselves can be viewed as pretty much disposable at that point. A VM gets corrupted? Wipe it, create a new one, run Ansible against it to set up the environment, then just give the node a label in your container orchestration platform of choice and watch as your business software is automatically provisioned on the node, bringing the total capacity of your cluster up once again.
For personal devices with no important credentials, or development boxes which are similarly unimportant, piping random stuff and trying to work around the problems with multiple SDKs is more permissible, however. Seeing as PHP, Ruby, Go, Java, .NET, Python and other technologies aren't always pleasant to work with if you have different projects that need different environments, as humorously pointed out here: https://xkcd.com/1987/
Containers aren't always comfortable to use for local development (especially with OSes like Windows locally, without WSL2, due to problems with bind mounts but perhaps are for components like DBs, Redis, MongoDB etc.), but in certain dev boxes they are also viable, thus making development even easier.
What are some difference between OpenJDK, Adoptium, Azul, BellSoft, etc. besides company dependencies and lifecycle? Which JDK is the fastest, or do certain JDKs perform faster under certain scenarios? Do any of these JDKs have any special features, or can they not do certain advanced reflection (e.g. for efficiency?)
I use IntelliJ so switching JDK is very easy, and most apps work on any JDK. Plus I doubt anything I release would be relevant in the long term (at least without the ability to upgrade JDK). So I really don't have to depend on any JDK, and seems like I don't have to worry about my JDK getting obsolete. Is there still a reason why I would prefer to use one JDK over another?
For example: > Use Corretto, only if you run Java applications directly on Amazon Linux 2 in AWS
Why?
I wonder if c# and mono is better in this respect
Java is actually nice in that a lot of distros are packaging a version manager for it. Arch and centos lead the pack in this. Although cent continues to be a mess about how many jdks and Jres are available.
Java often uses IDE but there are tools to run a REPL. Groovy had this before Java got it. You can use it to write Java, since Java code is Groovy. It comes with a GUI console into which you can type and evaluate too, or you can write script files and run them. It's not as fashionable nowadays as it used to be (now it's Kotlin, Scala, etc.) but it works great and can be useful for learning Java too.
There is definitely a lack "end-to-end" tutorials that don't rely on some form of tooling support. I would love to see more content on how to make a Java program with nothing but an editor and a command line, but I suspect there isn't much of a need for that. Java's tooling is exceptionally good, it's libraries mature and robust. Part of the reason every tutorial out there uses an IDE is because through quirks of history Java is basically an Enterprise programming environment where "Build the Right Thing" predominates over "Worse is Better".
EDIT: There is a REPL included with each JDK after 9 called JShell. It's useful if you just want to get up to speed or if you want to test something quickly.
As a side note, I appreciate that we have multiple tooling for Java. It doesn't sit well with me when the whole language, and its IDE and compiler and everything is bundled up in one package and that's all you have.
As for IDEs, I do recommend IntelliJ for writing the code, but in case you want to understand what happens behind the scenes, you can compile the source code directly in the terminal with `javac YourClass.java`, or *.java, depending on how many files you have.
It will by default place the resulting files in the current directory with the convention of creating directories for packages. If you had no package keyword in your files it will result in a simple YourClass.class file that you can run with `java YourClass` (do note that you run classes, not the file itself). If you had something like com.example as a package, it will be placed under WORK_DIR/com/example/YourClass.class.
It should be run from the current work_dir though!
The reason for that is the notion of a class-path, analog of the PATH variable of unix systems. It lists the package-aware class files, and defaults to the working dir, meaning it will find com.example.* files from here, but not elsewhere.
Dependencies are just that, they get concatenated to this class path and thus will be included.
EDIT: You can also just issue `java YourClassWithMain.java`, it will compile and run your class in one go
BTW. Limited platforms, but covers most of the cases (64 bit linux, windows, mac plus aarch64 for linux and mac)
I've seen, over the past few years, at least a dozen large threads on HN, Reddit, Slashdot, and elsewhere arguing over the JDK.
Usually they're a passionate mix of developers and PMs claiming they're still very confused by the licensing and update / security fix terms since JDK 8, while various Oracle engineers then shout back that the licensing issues are straight forward.
Personally, I've developed with Java for over a decade, and I have never really understood when I should use one version or the other. Oracle, Eclipse Foundation, IBM, and the other big players have not done a good job of marketing the various offerings, nor have they done a good job of clarifying for engineers what they should be installing on their local machines, development and test servers, production, etc.
This is probably the clearest fact sheet I've seen yet, and the links to different distributions with a concise "Use / Don't Use..." rating is indispensable.
I am still seeing a lot of projects on 8.
New Scala projects are generally on Corretto 11.
No, seriously, we need the same thing for .NET
....ok
A lot of apps just got stuck there.
HTTPS everywhere is a positive, and it is a good thing to do.
TLS is basically-free in 2021. It's fine and it is good to do.
What is/was common is internet providers' interest in making money on personal behavioral data in the traffic they transfer. DPI boxes to passively gather statistics or actively inject ads (and even rewrite existing ads) have been offered and tested since the 2000s across the world. Scale of big ISPs would make them Google's (&Co) competitors on personal behavioral data market, and mobile ISPs would combine it with location data, too. Moreover, they would be able to use Google's own tracking cookies to track individual users instead of inventing the classification systems (either by observing them in clear text, or by injecting scripts). The security and income of web services is the real reason for the global “HTTP is deprecated, switch to HTTPS” campaign, not you and your “privacy”.
Here are some pages that list some of the reasons:
The reason it doesn’t mention it is because it is a useless website.
openjdk 11.0.11 2021-04-20
OpenJDK Runtime Environment (build 11.0.11+9-Ubuntu-0ubuntu2)
OpenJDK 64-Bit Server VM (build 11.0.11+9-Ubuntu-0ubuntu2, mixed mode, sharing)