Access restriction: The type HttpServlet is not accessible due to restriction on required library xx

Access restriction: The type HttpServlet is not accessible due to restriction on required library xxxx\servlet-api.jar
在Eclipse是新建一个Servlet文件， 报错

缺少servlet-api.jar包

Access restriction: The type HttpServlet is not accessible due to restriction on required library C:\Program Files\Java\jdk1.6.0_02\jre\lib\ext\servlet-api.jar

解决方法

把C:\Program Files\Java\jdk1.6.0_02\jre\lib\ext\servlet-api.jar 拷贝到项目的 lib下就没报错了。