eclipse开发工具 -Access restriction 编译错误

Access restriction: The type Unsafe is not accessible due to restriction on required library D:\dev\Java\jdk1.6.0_31\jre\lib? \rt.jar

?

问题原因：Eclipse 默认把这些受访问限制的API设成了ERROR。

解决办法：将 Windows->Preferences->Java-Complicer->Errors/Warnings->Deprecated and restricted API，中的Forbidden references(access rules)设置为Warning，即可以编译通过。