some packages cannot be resolved in eclipse with gradle projects

In the past two days, I always got the errors "packages cannot be resolved" in eclipse with gradle projects. Initial I encountered the issue, I desperately wanted to resolved the issue. I tried several ways to do that by using solutions from web, however I didn’t get my issue resolved. Due to time constraint, I went back to the old mvn way to do the project. Today I have sometime to revisit the issue now.

This time, I am lucky to find The import org.springframework.data cannot be resolved in gradle. I read each answwers and did the actions in them. Luckly, My issue was resolved this time. The import org.springframework.data cannot be resolved in gradle indeed gives the answers, however it doesn’t give a clear structure to Facilitate understanding for us. I wrote down here in a clear structured way for me or us to understand cases and resolve them accordingly

There are several cases which will get the error messages. Here I will list my finding case by case. Hopefully it can save other sometime and me in future.