Common problems and solutions encountered in import packages in Eclipse

1. Find the error:
The Problems tab will have a detailed error description.
  If it is closed, reopen the method:
Eclipse, select Window, Show View, Other, Problems.



General errors and corrections:
Find the Libraries in the Java Build Path. If it is JRE System Libraries [jdk ... (version error)]
, delete the one that reported the error and re-import a Libraries Select Add Libraries->JRE System Libraries->next- > (select the jdk version of the corresponding JRE)