Screenrecorder-2022-09-18-14-20-15-175.mp4
(https://github.com/kartiksharmakk/CreditCardValidator-JNI/blob/main/app/src/main/cpp/native-lib.cpp)
Java_com_example_ccvalidator_MainActivity_CCValidator( JNIEnv* env,jobject /* this */,jstring UserInputCC)
{
std::string ccNumber= jstring2string(env,UserInputCC);
std::string finalResult;
uint32_t len = ccNumber.length();
int32_t doubleEvenSum = 0;
int32_t dbl;
int32_t i;
for (i = len - 2; i >= 0; i = i - 2) {
dbl = ((ccNumber[i] - 48) * 2);
if (dbl > 9) {
dbl = (dbl / 10) + (dbl % 10);
}
doubleEvenSum += dbl;
}
for (i = len - 1; i >= 0; i = i - 2) {
doubleEvenSum += (ccNumber[i] - 48);
}
finalResult=doubleEvenSum % 10 == 0 ? "Valid !" : "Invalid !";
return env->NewStringUTF(finalResult.c_str());
}class MainActivity : AppCompatActivity() {
private lateinit var binding: ActivityMainBinding
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
binding = DataBindingUtil.setContentView(this,R.layout.activity_main)
binding.CCInput.addTextChangedListener(CreditCardNumberFormattingTextWatcher())
binding.CCInput.setOnClickListener{
binding.resultText.text=""
}
binding.button.setOnClickListener {
//As we are using Credit Card Formating we have extra 3 characters as spaces so checking with 19 instead of 16
if(binding.CCInput.text.toString().length == 19) {
//Regex trims all spaces inside our string and sends it to our C++ Code for execution
var finalResult= CCValidator(binding.CCInput.text.toString().replace("\\s".toRegex(), ""))
binding.resultText.text = finalResult
Toast.makeText(applicationContext,
finalResult, Toast.LENGTH_SHORT).show()
}
else{
Toast.makeText(applicationContext,
"Please Enter only 16 digit Numbers", Toast.LENGTH_SHORT).show()
}
}
}
/**
* A native method that is implemented by the 'ccvalidator' native library,
* which is packaged with this application.
*/
external fun CCValidator(ccnumber:String):String