http://jira.baeldung.com/browse/BAEL-3586

testing-modules/junit-5-basics/src/test/java/com/baeldung/assertexception/ExceptionAssertionUnitTest.java

@@ -1,23 +1,32 @@
 package com.baeldung.assertexception;
 
 import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import org.junit.jupiter.api.Test;
 
 public class ExceptionAssertionUnitTest {
     @Test
     public void whenExceptionThrown_thenAssertionSucceeds() {
-        String test = null;
-        assertThrows(NullPointerException.class, () -> {
-            test.length();
+        Exception exception = assertThrows(NumberFormatException.class, () -> {
+            Integer.parseInt("1a");
         });
+
+        String expectedMessage = "For input string";
+        String actualMessage = exception.getMessage();
+
+        assertTrue(actualMessage.contains(expectedMessage));
     }
 
     @Test
     public void whenDerivedExceptionThrown_thenAssertionSucceds() {
-        String test = null;
-        assertThrows(RuntimeException.class, () -> {
-            test.length();
+        Exception exception = assertThrows(RuntimeException.class, () -> {
+            Integer.parseInt("1a");
         });
+
+        String expectedMessage = "For input string";
+        String actualMessage = exception.getMessage();
+
+        assertTrue(actualMessage.contains(expectedMessage));
     }
 }