创建项目后报错：Build path specifies execution environment javase-1.7.there are no JREs installed in the wor

创建项目后报错：

Build path specifies execution environment javase-1.7.there are no JREs installed in the workspace that are strictly compatible with this environment.

解决方法：

右键当前项目，选择 properties，在新窗口中选择 java build path，然后切换到 Libraries 选项卡，移除“JRE System Library[J2SE 1.6]”：
JRE System Library J2SE 1.6

接着单击“Add Library”，在新窗口中选择 JRE System Library：

JRE System Library

最后选择 “Executin Environment” 或默认 Workspace default JRE：
Workspace default JRE