Initial use of Eclipse encountered source not found problem

When looking at the class or interface of a system called in a program, I hold down the CTRL key and click on the class or interface without showing the source code, but not found.

Baidu on the search for a while to install plug-ins, but in turn, I this is the search system API, no need to install, and then find this method:

In the display source not found error interface, there is a choice Externam location button, and then select External file, under your JDK installation path, find the Src.zip files, this file is generally and Bin, Lib folder together.

When selected, it can be displayed.

Purely to move bricks for beginners Reference!

Initial use of Eclipse encountered source not found problem