Category: Tech Notes

Java 10 was released on 3/20/18 and can be downloaded from the Oracle JDK download site here. After installing on my Mac it shows both the yy.mm (18.3) version names and the “version 10”:

With each new JDK release it always seems there’s a slight lag before the IDEs catch up, but Eclipse has Java 10 support in the latest 4.7.3a release. I currently have the Oxygen.2 release (4.7.2):

… so I started an update to pick up the latest.

From Eclipse Marketplace the previous Java 10 support plugin is no longer needed if you have the latest Eclipse 4.7.3a release:

Updating my Eclipse to 4.7.3 however didn’t get me the ‘a’ release, so following the link in the Marketplace item above gives you a number of download options, or update sites to pick up the development build features (the page says this is version ‘Eclipse 4.7.3a Maintenance Build: M20180322-1835’)

I added the update site and selected all available updates and tried another update. After a restart when prompted I’ve now got version 4.7.3, but it’s not clear id this is the ‘a’ update or not:

Here’s a good summary of the major changes in Java 10. The feature I find most interesting is the addition of the var keyword for inferred local variable types.

Adding the Java 10 JDK location as a new JRE in Eclipse:

It gets recognized ok, but with a Maven pom.xml based project, the Maven Compiler plugin doesn’t seem to recognize either a compiler version of 1.10, 10, or 18.3, the project is still kept at the default of 1.5:

From the project preferences though, it is possible to add a JRE System Library for the JDK 10:

Trying out a snippet of code using the ‘var’ keyword, it’s not looking good so far:

Let’s go back to the Marketplace and see if we can install the Java 10 plugin anyway – even though it says it’s disabled, it looks like you can install it:

Well this is not good, but looks like we have an invalid update site, which we can probably remove:

Here it is, we can uncheck this one:

Unchecking it or removing it though doesn’t make the error go away, so no luck installing the plugin.

At this point it might be best to download one of the prebuild milestone builds from the 4.7.3a download page. Let’s try that next.

Ok, milestone build downloaded, and now we’ve definitely got the 4.7.3a build:

Interesting, this build doesn’t have any of the regular Eclipse JDT tools, so you have to install though from ‘Install Software’.

After installing the JDT plugin though, looks like I’ve still got the same issue with the var keyword not being recognized, despite selecting the Java 10 JRE as the platform default.

At this point doing some more searching around, I don’t think the var keyword support is included until Eclipse 4.8, see here: https://wiki.eclipse.org/JDT_Core/Plan/4.8/JEP286

Looks like we’ll have to wait for that Eclipse Photon 4.8 release to get into these new Java 10 features, which is not coming until June. At that point given that the new Java releases are coming every 6 month, we’ll already be over halfway to the Java 11 release.