Hi i'm developing an app that will use a fingerprint authentication to login, I create a class named FingerprintHandler and from that class i'm calling a method that will start another activity if fingerprint auth succeed, i also tried passing the context to the method but i still get an null object reference
FingerprintHanlder Class
#TargetApi(Build.VERSION_CODES.M)
public class FingerprintHandler extends FingerprintManager.AuthenticationCallback {
private Context context;
public FingerprintHandler(Context context){
this.context = context;
}
public void startAuth(FingerprintManager fingerprintManager, FingerprintManager.CryptoObject cryptoObject){
CancellationSignal cancellationSignal = new CancellationSignal();
fingerprintManager.authenticate(cryptoObject, cancellationSignal,0, this,null);
}
private void update(String s, boolean b){
MainActivity m = new MainActivity();
EditText etEmail,etPassword;
TextView tvFeedback = (TextView) ((Activity)context).findViewById(R.id.tvFeedback);
tvFeedback.setText(s);
if(b == false) {
tvFeedback.setTextColor(ContextCompat.getColor(context,R.color.colorAccent));
} else {
tvFeedback.setTextColor(ContextCompat.getColor(context,R.color.colorPrimary));
m.login(context.getApplicationContext(),context,"user","password");
}
}
}
MainActivity Class Method
public void login(final Context c1,final Context c, final String user, final String password) {
dialog = new ProgressDialog(c);
dialog.setMessage("Authenticating ...");
dialog.setCancelable(false);
dialog.setCanceledOnTouchOutside(false);
dialog.show();
StringRequest stringRequest = new StringRequest(Request.Method.POST, dBhelper.URL + "app-ess-login", new Response.Listener<String>() {
#RequiresApi(api = Build.VERSION_CODES.M)
#Override
public void onResponse(String response) {
Log.d("test: ", response);
try {
JSONObject collections = new JSONObject(response);
is_auth = collections.getInt("auth");
JSONArray jsonArrayUsers = collections.getJSONArray("user");
if(is_auth > 0) {
dBhelper.truncate();
for(int x = 0; x < jsonArrayUsers.length(); x++) {
JSONObject user = jsonArrayUsers.getJSONObject(x);
dBhelper.insertData(user.getInt("id"), user.getString("formal_name"), user.getString("email"), user.getString("job_title_name"), user.getString("schedule"));
}
dBhelper.username = user;
dBhelper.password = password;
dialog.dismiss();
Intent intent = new Intent(c, BundyClock.class);
startActivity(intent);
finish();
} else {
Toast.makeText(c, "Incorrect Email or Password", Toast.LENGTH_SHORT).show();
dialog.dismiss();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
dialog.dismiss();
Toast.makeText(c, "Error: " + error, Toast.LENGTH_SHORT).show();
}
}) {
#Override
protected Map<String, String> getParams() {
Map<String, String> params = new HashMap<>();
params.put("email", user);
params.put("password", password);
return params;
}
};
com.example.ess.AppController.getInstance().addToRequestQueue(stringRequest);
}
Thank you so much
You are calling startActivity(intent) And this is where you see the error. Why are you seeing this error?
You are calling MainActivity m = new MainActivity(); and m.login(). Activities are not a regular Java class and you need a lot of inheritance (BaseContext, etc) to make it work correctly. If you want to use the activity, you need to call startActivity(Intent) so it has all the necessary inheritance.
Since you are not starting MainActivity, it does not have proper context. When you call startActivity(intent) in your onResponse callback, it throws Null Pointer Exception as it does not have proper context.
How to fix this?
Do not use m.login(). You should move this method to some other class (not an activity). or make login a static method so that it is no tied to the MainActivity.
Use context.startActivity(intent) since you are passing context in login method.
Related
Recently I am working on Android project with Volley for registration and for further operation, I can make function for insertion and other one is for retrieval data. When insert button click 'Insert' function called and data has been inserted to database through volley, and at the same time retrieval function also called. But when USER clicked the button and function called then data showed(database inserted data) with blinking effect, look like loading.
I want to get rid of that effect. I want to show data smoothly without any blinking effect. I do searching but can not find any solution. Please suggest me solution I'am newbie so kindly short and efficient required.
package com.darkcoderz.parsejson;
public class MainActivity extends AppCompatActivity {
private Context mContext;
private Activity mActivity;
//private CoordinatorLayout mCLayout;
private TextView mTextView;
private String mJSONURLString = "http://192.168.10.4/volley/api.php";
String url = "http://192.168.10.4/volley/register.php";
private EditText sms;
private Button sendsms;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Get the application context
//mContext = getApplicationContext();
//mActivity = MainActivity.this;
// Get the widget reference from XML layout
//mCLayout = (CoordinatorLayout) findViewById(R.id.coordinator_layout);
mTextView = (TextView) findViewById(R.id.tv);
sms = (EditText) findViewById(R.id.sms);
sendsms = (Button) findViewById(R.id.sendsms);
final Handler firesms = new Handler();
firesms.post(new Runnable() {
#Override
public void run() {
getdata();
firesms.postDelayed(this, 100);
}
});
sendsms.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
reg();
}
});
getdata();
}
// insert
public void reg()
{
final String msg = sms.getText().toString();
StringRequest stringreq = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
if (response.equals("success"))
{
Toast.makeText(MainActivity.this, "Registration Successfull!", Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(MainActivity.this, "Username Already Exist!", Toast.LENGTH_SHORT).show();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(MainActivity.this, "Great Error "+error.toString(), Toast.LENGTH_LONG).show();
}
})
{
#Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String,String> params = new HashMap<>();
params.put("sms",msg);
return params;
}
};
RequestQueue reqest = Volley.newRequestQueue(MainActivity.this);
reqest.add(stringreq);
}
private void getdata() {
// Empty the TextView
mTextView.setText("");
// Initialize a new RequestQueue instance
RequestQueue requestQueue = Volley.newRequestQueue(MainActivity.this);
// Initialize a new JsonArrayRequest instance
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(Request.Method.GET, mJSONURLString, null, new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
// Do something with response
//mTextView.setText(response.toString());
// Process the JSON
try{
// Loop through the array elements
for(int i=0;i<response.length();i++){
// Get current json object
JSONObject student = response.getJSONObject(i);
// Get the current student (json object) data
// String firstName = student.getString("fname");
// String lastName = student.getString("lname");
String age = student.getString("email");
// Display the formatted json data in text view
mTextView.append("SMS : " + age);
mTextView.append("\n\n");
}
}catch (JSONException e){
e.printStackTrace();
}
}
},
new Response.ErrorListener(){
#Override
public void onErrorResponse(VolleyError error){
// Do something when error occurred
Toast.makeText(mContext, "Something Went Wrong", Toast.LENGTH_SHORT).show();
}
}
);
// Add JsonArrayRequest to the RequestQueue
requestQueue.add(jsonArrayRequest);
}
}
private void getdata() {
// Empty the TextView
mTextView.setText("");
// Initialize a new RequestQueue instance
RequestQueue requestQueue = Volley.newRequestQueue(MainActivity.this);
// Initialize a new JsonArrayRequest instance
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(Request.Method.GET, mJSONURLString, null, new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
//before parsing check your response is in JSONArray Format or JSONObject format
// Process the JSON
try{
}catch (JSONException e){
e.printStackTrace();
//print here to know JSONException if exists
Toast.makeText(mContext, "Exception"+e.toString(), Toast.LENGTH_SHORT).show();
}
}
}
},
new Response.ErrorListener(){
#Override
public void onErrorResponse(VolleyError error){
// Do something when error occurred
Toast.makeText(mContext, "Something Went Wrong", Toast.LENGTH_SHORT).show();
}
}
);
// Add JsonArrayRequest to the RequestQueue
requestQueue.add(jsonArrayRequest);
}
I'm writing a class with requests to rest API (Yandex disk). I use volley, but I do have some problems with getting a response from it. You can check the rest API here.
I use volley and I can get a response in the debugger, but not in my Activity.
Here is my Requests class
class Requests {
private String response_of_server, token;
private String url = "https://cloud-api.yandex.net/v1/disk";
private Context context;
Requests (String token, Context context) {
this.token = token;
this.context = context;
}
private void set_response_of_server(String response) {
this.response_of_server = response;
}
String get_response() {
return response_of_server;
}
void get_metadata_of_user() {
try {
/*Request*/
RequestQueue queue = Volley.newRequestQueue(this.context);
Response.ErrorListener error_listener = new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
error.printStackTrace();
}
};
Response.Listener<String> response_listener = new Response.Listener<String>()
{
#Override
public void onResponse(String response) {
set_response_of_server(response);
}
};
StringRequest getRequest = new StringRequest(Request.Method.GET, url+"?fields=user", response_listener, error_listener) {
#Override
public Map<String, String> getHeaders() {
Map<String, String> params = new HashMap<>();
params.put("Host", "cloud-api.yandex.net");
params.put("Authorization", token);
return params;
}
};
queue.add(getRequest);
/*Request end*/
} catch (Exception e) {
e.printStackTrace();
}
}
}
And the MainActivity where I want my response.
public class MainActivity extends AppCompatActivity {
private final String ID_OF_APP = "Your token of app";
private final String URL_FOR_CODE_QUERY = "https://oauth.yandex.com/authorize?response_type=token&client_id=" + ID_OF_APP;
private String SAVED_TOKEN = "";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btn_get_code = findViewById(R.id.btn_get_code); // send to get code page (yandex)
btn_get_code.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(Intent.ACTION_VIEW);
i.setData(Uri.parse(URL_FOR_CODE_QUERY));
startActivity(i);
}
});
Button btn_sign_in = findViewById(R.id.btn_sign_in);
btn_sign_in.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
EditText code_field = findViewById(R.id.code_field);
String token = code_field.getText().toString();
save_token(token);
try {
if(check_token()) {
//Toast.makeText(MainActivity.this, "You are successfully signed in", Toast.LENGTH_SHORT).show();
// TODO change activity
}
else {}
} catch (InterruptedException e) {
e.printStackTrace();
}
//Toast.makeText(MainActivity.this, "Something went wrong. Please, check your connection and try again later", Toast.LENGTH_SHORT).show();
}
});
}
private void save_token(String token) {
SharedPreferences sPref = getPreferences(MODE_PRIVATE);
SharedPreferences.Editor ed = sPref.edit();
ed.putString(SAVED_TOKEN, token);
ed.apply();
}
private String load_token() {
SharedPreferences sPref = getPreferences(MODE_PRIVATE);
return sPref.getString(SAVED_TOKEN, "");
}
private boolean check_token() throws InterruptedException {
String token = load_token();
String result;
Requests request = new Requests(token, this);
request.get_metadata_of_user();
result = request.get_response();
Toast.makeText(MainActivity.this, result, Toast.LENGTH_SHORT).show();
return !(result.equals("-1"));
}
}
check_token() function at the moment should just make a toast with a response of the server. However, I cannot get the Toast or any response coming back from the server.
You have a Requests class which has the function to call the server API which is Asynchronous. Hence, you will not get the result immediately after calling the request.get_metadata_of_user(); in your check_token() function.
Hence I would like to suggest you modify your Request class like the following.
public class Requests {
private String response_of_server, token;
private String url = "https://cloud-api.yandex.net/v1/disk";
private Context context;
private HttpListener listener; // Add a listener to get the callback functionality
Requests (String token, Context context, HttpListener listener) {
this.token = token;
this.context = context;
this.listener = listener; // initialize the listener here
}
private void set_response_of_server(String response) {
this.response_of_server = response;
listener.onResponseReceived(response); // Send the response back to the calling class
}
String get_response() {
return response_of_server;
}
void get_metadata_of_user() {
try {
RequestQueue queue = Volley.newRequestQueue(this.context);
Response.ErrorListener error_listener = new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
error.printStackTrace();
}
};
Response.Listener<String> response_listener = new Response.Listener<String>()
{
#Override
public void onResponse(String response) {
set_response_of_server(response);
}
};
StringRequest getRequest = new StringRequest(Request.Method.GET, url+"?fields=user", response_listener, error_listener) {
#Override
public Map<String, String> getHeaders() {
Map<String, String> params = new HashMap<>();
params.put("Host", "cloud-api.yandex.net");
params.put("Authorization", token);
return params;
}
};
queue.add(getRequest);
} catch (Exception e) {
e.printStackTrace();
}
}
}
Now the HttpListener class might look like the following. Create HttpListener.java and add the following code to create this as an interface.
public interface HttpListener {
public void onResponseReceived();
}
Hence you need to implement this interface in your MainActivity like the following.
public class MainActivity extends AppCompatActivity implements HttpListener {
private final String ID_OF_APP = "Your token of app";
// I fixed this part too. Please change if that is not useful
private final String URL_FOR_CODE_QUERY = "https://oauth.yandex.com/authorize?response_type=" + SAVED_TOKEN + "&client_id=" + ID_OF_APP;
private String SAVED_TOKEN = "";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// ... I omitted some code
Button btn_sign_in = findViewById(R.id.btn_sign_in);
btn_sign_in.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
EditText code_field = findViewById(R.id.code_field);
String token = code_field.getText().toString();
save_token(token);
try {
// if(check_token()) {
// The check_token function call is Async. This will not return immediately. Hence you might consider removing this if part. Simply just call the function and listen to the callback function when the response is received
// }
check_token(); // Simply call the function here
} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
}
private void save_token(String token) {
SharedPreferences sPref = getPreferences(MODE_PRIVATE);
SharedPreferences.Editor ed = sPref.edit();
ed.putString(SAVED_TOKEN, token);
ed.apply();
}
private String load_token() {
SharedPreferences sPref = getPreferences(MODE_PRIVATE);
return sPref.getString(SAVED_TOKEN, "");
}
// I changed the return type as this is not returning anything.
private void check_token() throws InterruptedException {
String token = load_token();
String result;
Requests request = new Requests(token, this);
request.get_metadata_of_user();
// You will not get the response immediately here. So omit these codes.
// result = request.get_response();
// Toast.makeText(MainActivity.this, result, Toast.LENGTH_SHORT).show();
// return !(result.equals("-1"));
}
#Override
public void onResponseReceived(String response) {
// Here is your response. Now you can use your response
// and can perform the next action here.
}
}
Please note that, the code is not tested. Please modify as per your requirement. I hope that helps you to understand the problem.
I have a super basic register script in android studio. Im trying to get it to connect to a php file located in the Localhost of XAMMP. My question is unique because i directing my script to a specific localhost url, not searching on the internet. The URL is accurate too, unless it has to be changed BACK to being localhost(not ip). The error code is
E/Create User: com.android.volley.NoConnectionError:
java.io.EOFException
here is the register request;
public class RegisterRequest extends StringRequest {
private static final String REGISTER_REQUEST_URL = "http://(ip address):3306/testing/Register.php";
private Map<String, String> params;
public RegisterRequest(String username, String password,String isAdmin,
Response.Listener<String> listener,
Response.ErrorListener errListener){
super(Method.POST, REGISTER_REQUEST_URL,listener,errListener);
params = new HashMap<>();
params.put("username",username);
params.put("password",password);
params.put("isAdmin",isAdmin+"");
}
public Map<String, String> getparams() {
return params;
}
}
here is the CreateUser class;
public class CreateUser extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_create_user);
this.setTitle("Create User");
final EditText username1 = findViewById(R.id.Createusername);
final EditText password1 = findViewById(R.id.CreatePassword);
final Switch isAdmin = findViewById(R.id.isadmin);
final Button createuser = findViewById(R.id.createuserbtn);
if (getIntent().hasExtra("com.example.northlandcaps.crisis_response")){
isAdmin.setVisibility(View.GONE);
}
createuser.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
final String username = username1.getText().toString();
final String password = password1.getText().toString();
final String isadmin = isAdmin.getText().toString();
Response.Listener<String> responseListener = new Response.Listener<String>() {
#Override
public void onResponse(String response) {
try {
JSONObject jsonResponse = new JSONObject(response);
boolean success = jsonResponse.getBoolean("success");
if (success){
Intent intent = new Intent(CreateUser.this, MainActivity.class);
startActivity(intent);
}else{
AlertDialog.Builder builder = new AlertDialog.Builder(CreateUser.this);
builder.setMessage("Register Failed")
.setNegativeButton("Retry",null)
.create()
.show();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
};
RegisterRequest registerRequest = new RegisterRequest(username,password,isadmin,responseListener,errorListener);
RequestQueue queue = Volley.newRequestQueue(CreateUser.this);
queue.add(registerRequest);
}
});
}
Response.ErrorListener errorListener = new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(getApplicationContext(), String.valueOf(error), Toast.LENGTH_SHORT).show();
Log.e("Create User", error+"");
}
};
The php file, like i said, is inside htdocs inside of XAMMP. both apache and mysql are running, however, someone said i may not have my php script invoked by apache. Or that php even enabled on my Apache server.
try this
int socketTimeout = 500000;//30 seconds - change to what you want
RetryPolicy policy = new DefaultRetryPolicy(socketTimeout, DefaultRetryPolicy.DEFAULT_MAX_RETRIES, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);
stringRequest.setRetryPolicy(policy);
// Creating RequestQueue.
RequestQueue queue = Volley.newRequestQueue(CreateUser.this);
// Adding the StringRequest object into requestQueue.
queue.add(registerRequest);
I have a button, part of whose functionality is in a class, that is in another class file in the same package. Is this the way how it is supposed to be done or I can somehow pass the instance of the current activity and then use whatever methods or fields it has in the methods of the second class.
public class LogInScreen extends AppCompatActivity {
Button logInButton;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_log_in_screen);
logInButton = findViewById(R.id.button_login);
userText = findViewById(R.id.editText_user);
passText = findViewById(R.id.editText_pass);
}
public void logIn(View view) {
logInButton.setEnabled(false);
String username = userText.getText().toString();
String password = passText.getText().toString();
BackendConnectionService.encodeCredentials(username, password);
RequestQueue requestQueue = Volley.newRequestQueue(this);
BackendConnectionService.handleSSLHandshake();
// here I put the button
requestQueue.add(BackendConnectionService.createLogInRequest(this, logInButton));
}
}
Declaration of the second class
public class BackendConnectionService {
// some class declarations
static JsonArrayRequest createLogInRequest(Context packageContext, Button button){
final Context context = packageContext;
final Button b = button;
return new JsonArrayRequest(
Request.Method.GET,
PALLETE_URL,
null,
new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
Intent intent = new Intent(context, PalletsScreen.class);
context.startActivity(intent);
b.setEnabled(true);
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e("REST ResponseErr", error.toString());
Toast.makeText(context, error.toString(), Toast.LENGTH_LONG).show();
b.setEnabled(true);
}
}) {
#Override
public Map<String, String> getHeaders() throws AuthFailureError {
HashMap<String, String> headers = new HashMap<>();
headers.put(autorisation, encodedCredentials);
return headers;
}
};
}
}
To be honest with you, you already did it :). You just need to know how to use it. Let's say that you want to use your LogInScreen in your createLogInRequest method:
static JsonArrayRequest createLogInRequest(Context packageContext, Button button){
final Context context = packageContext;
final Button b = button;
LogInScreen logInScreen = null;
if(context instanceof LogInScreen) {
logInScreen = (LogInScreen) context;
}
//...
}
How can I call the method "loginprep" of the LoginActivityClass from the FingerPrintClass?
See in the code...I wrote in where I want to call the loginprep with: "//Here I need the method loginprep() from the LoginActivity class"
FingerprintHandler.java
public class FingerprintHandler extends FingerprintManager.AuthenticationCallback {
private Context context;
// Constructor
public FingerprintHandler(Context mContext) {
context = mContext;
}
public void startAuth(FingerprintManager manager, FingerprintManager.CryptoObject cryptoObject) {
CancellationSignal cancellationSignal = new CancellationSignal();
if (ActivityCompat.checkSelfPermission(context, Manifest.permission.USE_FINGERPRINT) != PackageManager.PERMISSION_GRANTED) {
return;
}
manager.authenticate(cryptoObject, cancellationSignal, 0, this, null);
}
#Override
public void onAuthenticationError(int errMsgId, CharSequence errString) {
Toast.makeText((Activity)context, "Fingerprint Authentication error.", Toast.LENGTH_LONG).show();
}
#Override
public void onAuthenticationHelp(int helpMsgId, CharSequence helpString) {
Toast.makeText((Activity)context, "Fingerprint Authentication help.", Toast.LENGTH_LONG).show();
}
#Override
public void onAuthenticationFailed() {
Toast.makeText((Activity)context, "Fingerprint Authentication failed.", Toast.LENGTH_LONG).show();
}
#Override
public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
//Here I need the method loginprep() from the LoginActivity class
}
}
LoginActivity.java
public class LoginActivity extends AppCompatActivity {
public void loginprep() {
SharedPreferences sharedPreferencesF = getSharedPreferences("loginDatasFinger", Context.MODE_PRIVATE);
String urn = sharedPreferencesF.getString("username", "");
String pwd = sharedPreferencesF.getString("password", "");
loginUser(urn, pwd);
}
private void launchHomeScreen() {
Intent homeActivity = new Intent (LoginActivity.this,HomeActivity.class);
LoginActivity.this.startActivity(homeActivity);
finish();
}
public void loginUser(final String urn, final String pwd){
pd = ProgressDialog.show(LoginActivity.this, "", "Loading...");
StringRequest stringRequest = new StringRequest(Request.Method.POST, LOGIN_URL,
new Response.Listener<String>() {
#Override
public void onResponse(String response) {
try {
JSONObject jsonResponse = new JSONObject(response);
System.out.println("JSON RESPONSE: " + jsonResponse.toString());
boolean success = jsonResponse.getBoolean("success");
if (success) {
launchHomeScreen();
pd.dismiss();
Toast.makeText(LoginActivity.this,"Welcome back " + urn,Toast.LENGTH_LONG).show();
SharedPreferences sharedPref = getSharedPreferences("loginDatas", Context.MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPref.edit();
editor.putString("username", urn);
editor.putString("password", pwd);
editor.apply();
}
else {
loginButton.setBackgroundColor(0x73000000);
Toast.makeText(LoginActivity.this,"Wrong Username or Password!",Toast.LENGTH_LONG).show();
pd.dismiss();
}
}
catch (JSONException e) {
loginButton.setBackgroundColor(0x73000000);
e.printStackTrace();
pd.dismiss();
Toast.makeText(LoginActivity.this,response,Toast.LENGTH_LONG).show();
}
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
loginButton.setBackgroundColor(0x73000000);
pd.dismiss();
System.out.println("Error: " + error);
}
}){
#Override
protected Map<String,String> getParams(){
Map<String,String> params = new HashMap<>();
params.put(KEY_USERNAME,urn);
params.put(KEY_PASSWORD,pwd);
return params;
}
};
RequestQueue requestQueue = Volley.newRequestQueue(this);
requestQueue.add(stringRequest);
}
}
Following:
MainActivity mActivity = new MainActivity();
this is not the way Android is expecting you to create new instances of an activity, normally you wait the onCreate callback as described in the activity lifeCycle...
no following that approach you will need another way to communicate 2 different activities, what way must be taken depends on the specific arch of your application... the most commonly implemented could be using self defined interfaces and implement you custom callbacks...
You're writing a FingerPrint callback class, which means there is some onAuthenticationSucceeded method that is called when the "authentication succeeds."
How about you implement your own callback to pass back into the LoginActivity?
In other words, you'd
1) Write an interface
public interface LoginListener {
void onLoginSuccess();
void onLoginFailed();
}
2) Have the Activity implements LoginListener and have the Activity method of onLogin do your non-static stuff with the SharedPreferences,
public class LoginActivity extends AppCompatActivity
implements LoginListener {
public static final String KEY_USERNAME = "username";
public static final String KEY_PASS = "password";
private FingerprintHandler fingerprintHandler;
#Override
public void onLoginFailed() { }
#Override
public void onLoginSuccess() {
SharedPreferences sharedPrefs = getSharedPreferences("loginDatasFinger", Context.MODE_PRIVATE);
String urn = sharedPrefs.getString(KEY_USERNAME, "");
String pwd = sharedPrefs.getString(KEY_PASS, "");
loginUser(urn, pwd);
}
#Override
public void onCreate(Bundle b) {
super.onCreate(b);
setContentView(R.layout.activity_login);
fingerprintHandler = new FingerprintHandler(this);
}
// public void loginUser(final String urn, final String pwd){ }
}
3) Expect to pass in a LoginListener as a parameter to that separate class.
public class FingerprintHandler extends FingerprintManager.AuthenticationCallback {
private final Context mContext;
private LoginListener mListener;
// Constructor
public FingerprintHandler(Context context) {
mContext = context;
if (context instanceof LoginListener) {
this.mListener = (LoginListener) context;
} else {
throw new ClassCastException("FingerprintHandler: context must implement LoginListener!");
}
}
4) And you do then can use your callback from the other callback.
#Override
public void onAuthenticationSucceeded(FingerprintManager.AuthenticationResult result) {
if (mListener != null) {
mListener.onLoginSuccess();
}
}