Java – Import the Hadoop source code into Intellij

I want to import hadoop source code 2.7.2 in intellij IDe.
I like that:
File – Existing Project – Maven – Select POM .xml in Hadoop 2.7.2. Source File – I get an error in the Maven Project View after importing.

Does anyone know what to do?
I read Import Maven dependencies in IntelliJ IDEA. But it didn’t work.
Thanks

I think there is a problem with the PSI cache.

So try file -> to invalidate the cache/restart:

Note: This will clear all shelved changes.

I guess you won’t have this problem because you’re still importing the project.