Code autocomplete and reference hint are slow in java JDK 9.0.1

[khe817]

Code autocomplete and reference hint are significantly slower (5 to 10 seconds waiting for hints to load) in Java JDK 9.0.1 with maven projects as compared to previous Java JDK versions (1.7.x, and 1.8.x) (hints are loaded under 1 second). Half of the time, hints don't load at all.

Environment

• Operating System: windows 10
• JDK version: 9.0.1
• Visual Studio Code version: 1.19.1
• Java extension version: 0.16.0

Additional information

• Maven pom.xml configurations:

<properties>
	<java.version>9</java.version>
</properties>

If java.version is set to 1.8 in pom.xml, code completion and reference hints work fine.

[fbricon]

Performance is indeed abyssmal.

We need to check if updating to a newer version of JDT helps or if there's something truly broken in jdt.ls.

Performance seemed to be linked to the amount of opened Java classes in the workspace. On every keystroke, we're evicting/rebuilding the AST cache for all files and revalidating everything. For the same project, with 7 files opened, validation seems to be 10 times slower on jdk9.

[fbricon]

Seems fixed with the update to Eclipse Photon in the latest jdt.ls builds

[khe817]

I updated to the newest released version (0.18.1). The issue is now worse with no code completion popping up at all when I type an object and wait for its functions hints to show.

Reference hint, peek definition (Alt+F12), and go to definition (F12) for classes defined in a local project (vs classes from imported package in pom.yml) also now do not work. An error "No definition" pops instead.

Reference hint, peek definition (Alt+F12), and go to definition (F12) also do not work for java core classes like List, String, ArrayList ...

I have open a new issue: #428