### Question:
JCEHandler { byte[] doCryptStuff(byte[] data, Key key, int direction) throws JCEHandlerException { return doCryptStuff(data, key, direction, CipherMode.ECB, null); } JCEHandler(String jceProviderClassName);  JCEHandler(Provider provider); Key generateDESKey(short keyLength); byte[] encryptDESKey(short keyLength, Key clearDESKey, Key encryptingKey); Key decryptDESKey(short keyLength, byte[] encryptedDESKey, Key encryptingKey, boolean checkParity); byte[] encryptData(byte[] data, Key key); byte[] decryptData(byte[] encryptedData, Key key); byte[] encryptDataCBC(byte[] data, Key key, byte[] iv); byte[] decryptDataCBC(byte[] encryptedData, Key key, byte[] iv); byte[] generateMAC(byte[] data, Key kd, String macAlgorithm);  }### Answer:
@Test public void testDoCryptStuffThrowsJCEHandlerException() throws Throwable { jCEHandler = new JCEHandler((Provider) null); byte[] bytes = new byte[1]; Key key = new SecretKeySpec(bytes, "testJCEHandlerParam2"); byte[] data = new byte[3]; try { jCEHandler.doCryptStuff(data, key, 100); fail("Expected JCEHandlerException to be thrown"); } catch (JCEHandlerException ex) { if (isJavaVersionAtMost(JAVA_14)) { assertEquals("java.lang.NullPointerException", ex.getMessage(), "ex.getMessage()"); assertNull(ex.getNested().getMessage(), "ex.getNested().getMessage()"); } else { assertEquals("java.lang.NullPointerException: Cannot invoke \"java.security.Provider.getName()\" because \"this.provider\" is null", ex.getMessage(), "ex.getMessage()"); assertEquals("Cannot invoke \"java.security.Provider.getName()\" because \"this.provider\" is null", ex.getNested().getMessage(), "ex.getNested().getMessage()"); } assertEquals("testJCEHandlerParam2", key.getAlgorithm(), "(SecretKeySpec) key.getAlgorithm()"); } }
@Test public void testDoCryptStuffThrowsNullPointerException() throws Throwable { byte[] data = new byte[4]; try { jCEHandler.doCryptStuff(data, null, 100); fail("Expected NullPointerException to be thrown"); } catch (NullPointerException ex) { if (isJavaVersionAtMost(JAVA_14)) { assertNull(ex.getMessage(), "ex.getMessage()"); } else { assertEquals("Cannot invoke \"java.security.Key.getAlgorithm()\" because \"key\" is null", ex.getMessage(), "ex.getMessage()"); } } }