No compiler is provided in this environment. Perhaps you are running on a JRE rather than a JDK

解决办法：
　　1、eclipse菜单 - Window - Preferences- Java - Installed JREs 将配置的JRE定位到JDK，例如JRE home：D:Program Files (x86)Javajdk1.6.0_45
　　2、ALT+F5 进行 update project 。
　　3、Debug or Run again.