Eclipse 编译错误 Access restriction:The type *** is not accessible due to restriction on... 解决方案

报错：
Access restriction:The type JPEGCodec is not accessible due to
restriction on required library C:\Program Files\Java\jre6\lib\rt.jar

解决方法：

Project ->Properties -> java build path-> libraries，

先remove掉JRE System Library，然后再Add Library重新加入。