### Question:
JCEHandler { public byte[] decryptData(byte[] encryptedData, Key key) throws JCEHandlerException { return doCryptStuff(encryptedData, key, Cipher.DECRYPT_MODE); } 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 testDecryptDataThrowsNullPointerException() throws Throwable { try { new JCEHandler((Provider) null).decryptData("testString".getBytes(), null); 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()"); } } }