In debug mode Arraylist's logical structure is Array

Question

I run my tests in Spring Tool Suite 4 in debug. (On regular manual test of the code, everything works). In the code I initialize an ArrayList<>.

ArrayList<MyEntity> lst = new ArrayList<MyEntity>()

but the lst variable shows up as null and with the following error message:

Error   The method toArray() is undefined for the type Collection___

When I try to edit the logical structure it shows:

Type: Collection(java.util.Collection) Show As: Array[contributed by org.eclipse.jdt.debug] 
Preview: return toArray();

This issue only shows up when I try to debug my tests.

I have to admit: I still dont get what exactly you are doing, and what the problem is. Maybe this is one of the occasions where a screenshot is required.... — GhostCat, Jun 21 '19 at 13:36
this seems to be a bug with java 11 and eclipse https://bugs.eclipse.org/bugs/show_bug.cgi?id=545739 — Toerktumlare, Jun 21 '19 at 13:55
this is the main bugreport https://bugs.eclipse.org/bugs/show_bug.cgi?id=543604 — Toerktumlare, Jun 21 '19 at 13:55

score 1 · Accepted Answer · edited Jun 20 '20 at 09:12

1

Well, I have the same issue on several machines with a lot of different Oracle and OpenJDK JVMs.

Update

I just updated one of the failing STS4 installations to the latest version, and the problem seems to be gone. The version I received was:

edited Jun 20 '20 at 09:12

Community

answered Jun 24 '19 at 22:40

JüR

I havent implemented on my own system, because we managed to avoid problems with this bug, but according to your picture you got the idea of the bug and you found an actual solution. Thank you :) – Kristóf Horváth Jun 25 '19 at 10:54