IntelliJ IDEA can not auto import

I'm using IntelliJ 2016.1.2.

When I create a java.sql.Timestamp and enter alt + enter for auto import, my IntelliJ seems can not give me a hint about it. I have to import it mannully.

Other class in java.sql.* works fine.

How to sovle this problem? Thank you very much.

It might be that the class is excluded from Auto Import

• open the Settings Dialog CTRL-ALT-S
• navigate to Editor -> General -> Auto Import
• on the right side there is a list Exclude from Import and Completion where