Myeclipse Build path specifies execution environment JavaSE-1.7. There are no J

1. 问题描叙：
2.         Build path specifies execution environment JavaSE-1.7. There are no JREs installed in the workspace that are strictly compatible with this environment. 
3. 解决方式：
4.      进入Configure Build Path--> remove 掉JRE System Library [JavaSE-1.7]--->Add Library选择JRE System Library点击next选择默认jre