To migrate launch configs between different workspaces simply copy the .launch files from:

/eclipse-workspace/.metadata/.plugins/org.eclipse.debug.core/.launches

• Automatically organise imports: Ctrl+Shift+O
• Static import: Ctrl+Shift+M

To exclude annoying packages or classes when doing automatic organisation of imports with Ctrl+Shift+O create a a “Type Filter” under Windows → Preferences → Java → Appearance → Type Filters.

My current list:

scala.*
java.awt.*
junit.*
org.joda.*

As of 2018 the subversive project seems to be dead, so we must use subclipse. Install it from the Eclipse Marketplace and then:

sudo apt install libsvnclientadapter-java

Specify the folder where libsvnjavahl-1.so is located as library path in eclipse.ini (the line must come directly after -vmargs)

-vmargs
-Djava.library.path=/usr/lib/x86_64-linux-gnu/jni

see also https://github.com/subclipse/subclipse/wiki/JavaHL-on-Linux

see KDE 5 / Kubuntu Tipps & Tricks

Start with:

GTK_OVERLAY_SCROLLING=0 

This will permanently reserve place for the scroll bars and no content will be hidden.

See https://bugs.eclipse.org/bugs/show_bug.cgi?id=519728

Using Kubuntu 20.04 I don't like the miniscule scroll bars that slightly widen when hovering over them. Setting a min size works as follows:

Edit .config/gtk-3.0/gtk.css and add these lines:

.scrollbar.vertical slider, scrollbar.vertical slider {
    min-width: 7px;
}
.scrollbar.horizontal slider, scrollbar.horizontal slider {
    min-height: 7px;
}

This happens sometimes when upgrading a workspace to a new version of Eclipse (most recently to me when upgrading vom 2018.09 to 2018.12).

Window→Preferences→Java→Editor→Content Assist→Advanced

Now make sure the following are all ticked in the top and bottom sections:

• Java Non-Type Proposals
• Java Proposals
• Java Type Proposals

Apply the changes and then close and re-open your project and it will build the autocompletions which will then become available when you hit Ctrl-Space.

Source: https://www.chrisnewland.com/solved-eclipse-java-autocomplete-not-working-259