javatest.utils.OptionalTest Maven / Gradle / Ivy
package javatest.utils;
import java.util.NoSuchElementException;
import java.util.Optional;
public class OptionalTest {
static public void main(String[] args) {
System.out.println("OptionalTest.main:");
test(Optional.empty(), null);
test(Optional.empty(), 1);
test(Optional.of(1), 2);
test(Optional.ofNullable(1), 2);
test(Optional.ofNullable(null), 2);
testInt(Optional.empty());
testInt(Optional.of(7));
}
static private void test(Optional opt, T optDefault) {
System.out.println(opt.isPresent());
System.out.println(opt.orElse(optDefault));
try {
System.out.println(opt.get());
} catch (NoSuchElementException e) {
System.out.println(e.getMessage());
}
}
static private void testInt(Optional opt) {
System.out.println(opt.map(it -> it * 2));
}
}