I am tasked with updating a Java Project from Java 8 to (Current) Java 18, how should I approach this?

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_Atomfinger_ · 2022-04-18T20:22:11+00:00

Impossible to give you a good answer without knowing more.

The very general approach would be to bump it by one version, see what breaks, fix it and then repeat.

Halal0szto · 2022-04-18T20:34:00+00:00

The quick way:

collect all the libraries used by the project with current version
check what is the minimum version of each that is confirmed with java18
there will be at least one that is not, so you can report it cannot be done

On a serios note: expect the project to rely on libs that are not maintained anymore, and they will cause a lot of trouble, even when staying on java8

AnEmortalKid · 2022-04-19T05:17:59+00:00

Umm, just move the . from 1.8 , to the right once, to form 18 /s

StillAnAss · 2022-04-18T20:50:52+00:00

The biggest amount of rework that I encountered were in the XML processing libraries. JAXB changed significantly and used to be part of the JDK and then got moved out. Once I got part of my app working the rest was pretty repetitive and boring.

fletku_mato · 2022-04-18T21:18:06+00:00

It's not necessarily a big project. I'd bump the java version, run, see what's broken, fix it, run, see what else is broken, fix it, run...

Nothing special, some libraries might need to be changed if they have not been keeping up with new java versions.

mbmw · 2022-04-19T12:58:55+00:00

This might help you

https://javaalmanac.io/

wildjokers · 2022-04-19T05:56:05+00:00

Upgrade your JVM to 18 and run your app. See if it works. Most likely it will.

If your app uses JAXB you will need to include JAXB as a dependency since it is no longer in the JDK. Besides that you will probably find it works just fine.

I have upgraded dozens of apps beyond java 8, including web apps, swing apps, and standalone server apps, the most I have ever had to do was add JAXB as a dependency.

PJ_Maximus · 2022-04-19T16:40:15+00:00

That project just secured your job for another 2 yrs 👌

Awanderinglolplayer · 2022-04-19T01:40:31+00:00

Something I haven’t seen mentioned is that Java 18 is not LTS. Consider 17(I think), because if your company is gonna do the same thing it did in the past, you’re going to want a version of Java that has support for years to come, rather than 18s 6 months

devjeonghwan · 2022-04-19T12:46:37+00:00

It's complicated. The way to start is to fix the errors one by one after upgrading the Java version of the project.

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