java assert exception unitest

how-to-assert-exception.java

import static org.junit.jupiter.api.Assertions.assertThrows;
@Test
public void testUsernameIsNull() {
 
    Exception exception = assertThrows(IllegalArgumentException.class, () -> {
        User user = new User();
        user.setName(null);
    });
    Assert.assertEquals("expected message", exception.getMessage());
}