IntelliJ: Never use wildcard imports

It's obvious why you'd want to disable this: To force IntelliJ to include each and every import individually. It makes it easier for people to figure out exactly where classes you're using come from.

Click on the Settings "wrench" icon on the toolbar, open "Imports" under "Code Style", and check the "Use single class import" selection. You can also completely remove entries under "Packages to use import with *", or specify a threshold value that only uses the "*" when the individual classes from a package exceeds that threshold.

Update: in IDEA 13 "Use single class import" does not prevent wildcard imports. The solution is to go to Preferences (⌘ + , on macOS / Ctrl + Alt + S on Windows and Linux) > Editor > Code Style > Java > Imports tab set Class count to use import with '*' and Names count to use static import with '*' to a higher value. Any value over 99 seems to work fine.

File\Settings... (Ctrl+Alt+S) Project Settings > Editor > Code Style > Java > Imports tab Set Class count to use import with '*' to 999 Set Names count to use static import with '*' to 999

https://i.stack.imgur.com/J4xwT.png

(On IntelliJ IDEA 13.x, 14.x, 15.x, 2016.x, 2017.x)

Like a dum-dum I couldn't figure out why none of these answers were working for my Kotlin files for java.util.*, so if this is happening to you then:

Preferences
> Editor
> Code Style
> **Kotlin**
> Imports
> Packages to Use Import with '*'
-> Remove 'java.util.*'

https://i.stack.imgur.com/Da7X3.png

IntelliJ IDEA 2018.1.4 (Ultimate Edition) built on May 16, 2018

The solution above was not working for me. I had to set 'class count to use import with '*'' to a high value, e.g. 999.

In Android Studio with Kotlin.

File > Settings,

Editor > Code Style > Kotlin, then "Imports" tab, select "Use single name import".

Also remove import java.util.*.

https://i.stack.imgur.com/eBT1d.png

This applies for "Intellij Idea- 2020.1.2" on window

Navigate to "IntelliJ IDEA->File->Settings->Editor->Code Style->java".

https://i.stack.imgur.com/94GRg.png

This applies to "IntelliJ IDEA-2019.2.4" on Mac.

Navigate to "IntelliJ IDEA->Preferences->Editor->Code Style->Kotlin". The "Packages to use Import with '' section on the screen will list "import java.util."

https://i.stack.imgur.com/BXCYt.png

Click anywhere in that box and clear that entry. Hit Apply and OK.

https://i.stack.imgur.com/xwDkO.png

If non of above works for you, then it is worth to check if you have any packages under Preference > Editor > Code Style > Java > Imports > Packages to Use Import with "*"

Adding the following to the .editorconfig file saves having to apply the settings every time the project is reimported from scratch:

[*.java]
ij_java_names_count_to_use_import_on_demand = 999
ij_java_class_count_to_use_import_on_demand = 999

Shortcut doing this on Mac: Press command+Shift+A (Action) and type "class count to use import with *" Press Enter. Enter a higher number there like 999

If you don't want to change preferences, you can optimize imports by pressing Ctrl+Option+o on Mac or Ctrl+Alt+o on Windows/Linux and this will replace all imports with single imports in current file.

On a related note: If your java.util packages are still not resolved to single imports today then it might be, that you are looking at a Kotlin file while trying to change the settings for Java like I did. :-) There are the same settings for Kotlin that fixes that.