右击有main方法的类
===> Run as
===> Run Configurations
===>双击java application
===> 单击有main方法的类
===>选中classpath选项卡
===> remove掉Bootstrap Entries下的android.jar
===> 然后点击advanced
===> Add Library
===>JRE System Library
===>next
===>最后finish
===>Run