The “import java.util.function cannot be resolved” error

Question

I\'m trying to run this practice script from the standard Oracle Java tutorials.

This seems to be a common error and I\'ve used SO resources to make attempts to fix

Answer 1

I had something similar with Apache Camel: the following function was not working anymore

String headerKey = exchange.getIn().getHeader("headerKey",String.class);

because of the error-message:

The type java.util.function.Supplier cannot be resolved. It is indirectly referenced from required .class files

To solve the issue I change the casting and it worked afterwards:

String headerKey = (String) exchange.getIn().getHeader("headerKey");

maybe it helps you or somebody else.

One other point to mention here would be the Apache Camel version itself as stated on the official page linked here.