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Reset Java Version - Switch from 1.8 to 21 [message #1863730]

Fri, 23 February 2024 10:48

Eclipse User

I'm a long tome Java developer and Eclipse user in the past. After 10 years of PHP web development I'm returning to Java and systems programming.

I've installed the latest Eclipse IDE (4.30)

All my projects are Maven projects.

I'm having difficulty switching the JRE from 1.8 to 21. It is ridiculous that this is not easy to do. I'm trying to use the new record type and my code won't compile.

How do I do this and also make the setting is permanent?

Re: Reset Java Version - Switch from 1.8 to 21 [message #1863733 is a reply to message #1863730]

Fri, 23 February 2024 12:49

Eclipse User

Window -> Preferences -> Java -> Installed JREs then Add... it, and make it the default.

Re: Reset Java Version - Switch from 1.8 to 21 [message #1863734 is a reply to message #1863733]

Fri, 23 February 2024 13:01

Eclipse User

There is NO Window -> Preferences

I use Eclipse->Settings->Java->Installed JREs

There is only one:

/Library/Java/JavaVirtualMachines/jdk-21.jdk/Contents/Home/lib/jrt-fs.jar

I see the Windows->Preferences thing all the time looking for how to do things. I assume the Mac version doesn't have that menu and the Windows version does.

For some reason my projects except for one, (I have 8), are stuck on 1.8

I suspect if I deleted and then recreated them it would work properly but I don't want to do that.

Re: Reset Java Version - Switch from 1.8 to 21 [message #1863736 is a reply to message #1863734]

Fri, 23 February 2024 13:29

Eclipse User

If you're using Maven, try updating the Maven project (IIRC the default keybind is Alt+F5) after changing the Java versions in your POM. This should update the compiler settings.

Re: Reset Java Version - Switch from 1.8 to 21 [message #1863737 is a reply to message #1863736]

Fri, 23 February 2024 14:13

Eclipse User

Erik Brangs wrote on Fri, 23 February 2024 18:29

If you're using Maven, try updating the Maven project (IIRC the default keybind is Alt+F5) after changing the Java versions in your POM. This should update the compiler settings.

Like that:

index.php/fa/44001/0/

Attachment: Screenshot 2024-02-23 211200.png
(Size: 63.51KB, Downloaded 7736 times)

Re: Reset Java Version - Switch from 1.8 to 21 [message #1863743 is a reply to message #1863737]

Fri, 23 February 2024 20:42

Eclipse User

Ok, that worked. Doesn't everyone use Maven? Not sure why I had to do that.

Thanks.

Re: Reset Java Version - Switch from 1.8 to 21 [message #1863744 is a reply to message #1863743]

Sat, 24 February 2024 00:13

Eclipse User

Donald Paul Winston wrote on Sat, 24 February 2024 01:42

Ok, that worked. Doesn't everyone use Maven? Not sure why I had to do that.

Thanks.

I did not use Maven for many years, but I gave it a try, and I was hooked.

For me, the major benefits are:

Automatic download of dependencies (jars)
A standard project structure
Checking for dependency updates
Central local repository
A nice set of shared components: https://maven.apache.org/shared/index.html

I am a 71-year-old retired programmer. I use Java for brain training.
Using the shared components, I wrote a bunch of utilities to handle the house chores, and that was fun.

When the numbers of dependencies that you use starts to grow, a tool like Maven is a must.

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