在Eclipse中編寫Java代碼時,用到了BASE64Decoder,import sun.misc.BASE64Decoder;但是Eclipse提示: Access restriction : The type BASE64Decoder is not accessible due to restriction on required library C:\Program files\java\jre6\lib\rt.jar Access restriction : The constructor BASE64Decoder() is not accessible due to restriction on required library C:\Program files\java\jre6\lib\rt.jar 搞不懂是爲何,最後在http://forums.dzone.com/eclipse/384-access-restriction- problems.html找到答案,只須要在project build path中先移除JRE System Library,再添加庫JRE System Library,從新編譯後就一切正常了。