not accessible due to restriction

在引用如下包报错
import sun.swing.DefaultLookup;

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

解决办法

sun.net包里的，在eclipse里默认是不让用的。解决办法是自定义access rules

工程上右键->工程属性->java builder path->Libraries标签，点击JRE System Library里面的Access rules，add sun/** 为accessible，如果该项存在，就edit