Access restriction on class due to restriction on required library

Question

I get this error message in Eclipse:

Access restriction: The type DirectoryWalker is not accessible
due to restriction on required library 
/Library/Java/Extensions/commons-io-1.4.jar

what does this mean? There's this other SO question on the same topic but it doesn't seem to apply in this case. I'm not creating a new java class, I'm trying to use one.

Answer 1

go to java build path and under Library tab, remove JRE System Library. Then again Add Library --> JRE System Library

Worked for me

Answer 2

This is my least-favorite error, I've run into it a few times, and the "restriction on required library" is just dull enough to leave you scratching your head. However, it's easy to fix.

The quickest way (I'm using Helios) is to go to Window->Preferences->Java->Compiler->Errors/Warnings, find and open the "Deprecated and Restricted API" bullet, and set Forbidden and Discouraged Reference to something other than Error.

"Warning" is usually best, as something out there in Java land is triggering this and you probably want a footnote on it. @SuppressWarnings and its cousins, 98% of the time, have the same effect on a programmer's personal and social logic as, say, an ether binge might. But that's just my humble analysis.

Best of luck!