The formatter for Groovy source code does not use the correct Java formatter settings for indentation. In the STS (Eclipse) "Java -> Code Style -> Formatter" preferences, I edit the format and in the "Profile" dialog. On the "Indentation" tab, I set "Tab policy" to "Spaces only", "Indentation size" to "2", and "Tab size" to "8". Now, when I select some Groovy code and press "Ctrl+Shift+F", the Groovy editor uses the "Tab size" value of 8 spaces to indent my code, not the indentation size of "2" spaces. The editor/formatter should use the indentation size, not the tab size for indentation. The tab size is just the number of spaces to use to represent a tab character (I set mine to match my printer's and terminal's default tab size); it should have no effect on the code formatting.