import sun.misc.BASE64Encoder results in error compiled in Eclipse

For this two imports;

import sun.misc.BASE64Encoder;
import sun.misc.BASE64Decoder;

I got this error:

Access restriction: The type BASE64Decoder is not accessible due to restriction on required library C:\Program Files\Java\jre6\lib\rt.jar

How can I resolve this error?

Go to Window-->Preferences-->Java-->Compiler-->Error/Warnings.
Select Deprecated and Restricted API. Change it to warning.
Change forbidden and Discouraged Reference and change it to warning. (or as your need.)

That error is caused by your Eclipse configuration. You can reduce it to a warning. Better still, use a Base64 encoder that isn't part of a non-public API. Apache Commons has one, or when you're already on Java 1.8, then use java.util.Base64.

Sure - just don't use the Sun base64 encoder/decoder. There are plenty of other options available, including Apache Codec or this public domain implementation.

Then read why you shouldn't use sun.* packages.