如何在方法中模拟对象

Question

I want to mock response object here when I call getHSMDecryptedData method from my test method.

private String getHSMDecryptedData(String keysetName, int groupIndex,
                                   String ksn, String encryptedData) {
    String decryptedData = null;
    try {
        DecryptData decrypt = new DecryptData();
        decrypt.setKeySet(keysetName);
        decrypt.setKsnDescriptor("906");
        decrypt.setKsn(ksn);
        decrypt.setKeyType(HSMKeyTypeDataModel.TYPE_BDK);
        decrypt.setEncryptionMode(HSMEncryptionMode.CBC);
        decrypt.setInputFormat(HSMDataFormat.HEX_ENCODED_BINARY);
        decrypt.setOutputFormat(HSMDataFormat.HEX_ENCODED_BINARY);
        decrypt.setMessage(encryptedData);

        // sending M2 command to HSM for decryption of encrypted data coming from CP
        DecryptDataResponse response = (DecryptDataResponse) HSMService.getInstance().processRequest(decrypt);

        System.out.println(response+"***************reponse");
        if (response != null && response.getResponseCode() == HSMResponseCodes.APPROVED) {
            decryptedData = response.getDecryptedMessage();
            TraceLog.Info(getClass(),
                "Message decrypted[" + decryptedData + "], original input[" + encryptedData + "], replacing original encrypted data!");
            if (decryptedData == null) {
            //  throw new FirstadatException("Unable to get the decrypted Data from HSM ");
            }
        }//FirstadatException

This is my test method:

HsmDataDecrypt hsmDataDecrypt = new HsmDataDecrypt();
    try {
        DecryptDataResponse response=mock(DecryptDataResponse.class);
        //response.
        Method method = hsmDataDecrypt.getClass().getDeclaredMethod("getHSMDecryptedData", String.class,int.class,String.class,String.class);

Answer 1

 DecryptDataResponse response = (DecryptDataResponse) HSMService.getInstance().processRequest(decrypt); 

You access the HSMService object via the Java Singleton Pattern . This kind of singletons are basically global variables which software developers consider being evil since the late 80s...

You better inject the HSMService object preferably as constructor parameter or any other dependency injection technique. In that case you can replace the HSMService object with a mock which in turn returns a mock of the DecryptDataResponse class on call of the processRequest method.