window

1、Window > Preference > Text Editors :  勾选Insert spaces for tabs  ,如果要在删除时也同时删除4个，就勾选remove multiple spaces on backspace/delete  ，然后apply

 

2、Window > Preferences > Java > Code Style > Formatter, 点击New，命名4tab确认后，修改Indentation > Tab policy 为 Spaces only,然后apply

 

3、如果要显示空格：Window > Preference > Text Editors ，勾选Show whitespace characters

 

Mac

1、Eclipse > Preference > Text Editors :  勾选Insert spaces for tabs  ,如果要在删除时也同时删除4个，就勾选remove multiple spaces on backspace/delete  ，然后apply

 

2、Eclipse > Preferences > Java > Code Style > Formatter, 点击New，命名4tab确认后，修改Indentation > Tab policy 为 Spaces only,然后apply

 

3、如果要显示空格：Eclipse > Preference > Text Editors ，勾选Show whitespace characters