Installing the androidadt plugin remains at calculating requirements and dependencies for a long time

If eclipse takes a long time to calculate requirements and dependencies (computing requirements and dependencies)
This problem usually occurs when you click "Install" and "calculating requirements and dependencies" is displayed, and the progress bar does not move. When you call out the system monitor, you will find that no traffic is downloaded. solution:

1. Remove the check box before "Contact all update sites during install to find required software" (visit all update sites before looking for the specified software), and then f returns to reinstall, then the problem is solved.

2. If the installation is performed locally and the network is disconnected, the problem can be solved.