sun.misc.BASE64Decoder 导入错误

import="sun.misc.BASE64Decoder"
出现错误提示为：Access restriction: The type BASE64Decoder is not accessible due to restriction 
on required library D:\ProgramFiles\MyEclipse\jre\lib\rt.jar
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安装国外论坛的方法解决了，如下：
1. Open project properties.
2. Select Java Build Path node.
3. Select Libraries tab.
4. Remove JRE System Library.
5. Add Library JRE System Library.