Eclipse content assist auto appends type for variable

Not a perfect solution:

Window->Preference->Java->Editor->Content Assist->Auto activation Triggers for Java: .ABCDEFGHIJKLMNOPQRSTUVWXYZ

In this way, only classes and types will be popped up for proposals.

Just a suggestion, the choice is up to you.

This is still a problem in Eclipse 2018-12 and it only seems to occur if you changed the Auto activation triggers for Java setting to e.g. ._abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ, which'll make the Content Assist (almost) always pop up, even without pressing Ctrl+Space (Windows).

There's a new setting that was added in Eclipse 2018-12 and makes it a bit less annoying (mentioned in the comments below the bug report):

In Window - Preferences - Java - Editor - Content Assist tick the Disable insertion triggers except 'Enter' box.

With this setting enabled, Content Assist is still going to trigger (depending on the other settings) but you have to press Enter to accept a suggestion.

Based on the discussion for Eclipse Bug 412992, check your Content Assist Auto Activation settings: Window->Preferences->Java->Editor->Content Assist

If, for example, characters a-z are listed as "Auto activation triggers for Java", you can remove them and the type name will not be auto-appended to a new variable name when you hit ' ' or ';'. It's up to you to determine the best configuration/tradeoffs for your style based on the available options.

It seems that it is not possible. See answers to Eclipse Bug 378588: https://bugs.eclipse.org/bugs/show_bug.cgi?id=378588