Resolution of red exclamation point when importing Java project

issue: Red exclamation mark when importing Java project (as shown)

Cause: Some of the jar packages introduced into the project are not the same as the locations on their computers;

Solution: The steps are as follows

(1) Right-click Red exclamation mark in the project ———— >build path ———— >configure build path, the following window appears:

(2) Remove the option to drop the Red Fork: JRE System library[jdk.7.0.72] (unbound), then add Library (e.g.):

(3) Check the JRE System Library ———— >next (as shown):

(4) The following window appears ———— >finish:

(5) Fix it.

Resolution of red exclamation point when importing Java project