Commons Lang、BitField#isAllSet()

import org.apache.commons.lang.BitField;

public class C2009042700 {
    public static void main(String[] args) {
        BitField bf;

        bf = new BitField(5);
        System.out.println(bf.isAllSet(15));

        bf = new BitField(7);
        System.out.println(bf.isAllSet(15));

        bf = new BitField(7);
        System.out.println(bf.isAllSet(7));

        bf = new BitField(15);
        System.out.println(bf.isAllSet(7));
    }
}

で、

true
true
true
false