Getting line numbers to appear and other preferences
To get the line numbers to appear in the editing pane of the Eclipse window, use menu item
Preferences -> General -> Editors -> Text Editors
A window like the one below will appear. Check the Show line numbers box.
We suggest also that you:
1. Set the displayed tab width to 4
2. Check the Highlight current line box
3. Check the Show range indicator box
4. Check the Show affordance in hover ... box and choose theEnrich after delay
5. Enable Drag and drop of text
When done, click box OK.