1, the steps of problems:
When Hello.java want to add a file when the wrong file type. Create a text file. When the file extension back to get rid of the idea is not recognized, it was found, it has been the color gray.
2, the solution to the problem:
Select idea left corner of File -> Settings -> Editor ---> File Types
Because it was new file type is text, the modified file type is java.
So the first step:
We just need to find the right side of File Types Text. Then the following window, sliding down to the bottom Hello there will be a file name. Deleted.
Step two:
We just need to find the right side of File Types Java and then sliding down to the very bottom of the window below Hello there will be a file name, delete.
third step:
Click the lower right corner of the window OK. Close the window.
