Commons Lang、BooleanUtils.negate()
import org.apache.commons.lang.BooleanUtils; public class C2009032200 { public static void main(String[] args) { System.out.println(BooleanUtils.negate(true)); System.out.println(BooleanUtils.negate(false)); System.out.println(BooleanUtils.negate(null)); } }
で、
false true null