Incompatible generic wildcard captures

Question

in the following snippet:

package test;

import java.util.Collection;
import java.util.Iterator;
import java.util.Map;

public class WildcardsTest

        

Answer 1

Do it like this and it will work:

private final Iterator>
> iterator;

You can still use the iterator like this:

public void foo(){
    while(iterator.hasNext()){
        Entry> entry = iterator.next();
        Collection value = entry.getValue();
    }
}

For reference, read the get and put principle (originally from Java Generics and Collections)