Split Editor Window in Eclipse

This is how to open the same file (for example, RecurrenceImpl.java) in a split editor window in Eclipse:

1. Right click your file name (i.e. the tab title)
2. Select New Editor
• Now you have two files with the same name opened in the same editor window
  
3. Left-click (don't release) on a RecurrenceImpl.java's tab, drag the cursor to the lower edge of the active editor, wait a second so that the cursor changes into a black filled arrow, and release the mouse button.

Learn More

1. Eclipse IDE Tutorial