The type javax.servlet.http.HttpServletRequest cannot be resolved.

The type javax.servlet.http.HttpServletRequest cannot be resolved. 如果在MyEclipse中遇到这种情况，也就是HttpServletRequest报红叉的时候，这样做1、右键工程找到build path项2、找到Add Libraries3、点击myEclipse Libraries，Next4、添加JavaEE 5OK