junit assertthrows code example

Example 1: junit 5 expected exception

@Test
void testExpectedException() {
 
  Assertions.assertThrows(NumberFormatException.class, () -> {
    Integer.parseInt("One");
  });
 
}

Example 2: junit 5 assert exception message

Throwable exceptionThatWasThrown = assertThrows(NullPointerException.class, () -> {
    codeThatThrows;
});

assertThat(exceptionThatWasThrown.getMessage(), equalTo("Message I expected to be thrown"));