Develop Reference

What is the Server URL of my Android Apk?

I am using PHP JSON Volley for authenticating my login activity .Currently i am giving the localhost and IP address to test my application (Please find my code below). But when the APK is generated , what is the URL that should be given ? Kindly guide.
public class LoginActivitywithConnection extends Activity {
private static final String TAG = "LoginActivitywithConnection";
private Button btnLogin;
private Button btnLinkToRegister;
private EditText usernameEditText;
private EditText inputPassword;
private ProgressDialog pDialog;
private SessionManager session;
private DbHandler db;
String userType;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
Log.i(TAG, "entered");
Intent i = this.getIntent();
Bundle data = i.getExtras();
if (data != null) {
String buttonClicked = data.getString("ButtonClicked");
if (buttonClicked.equals("asha")) {
userType = "asha";
} else if (buttonClicked.equals("anm")) {
userType = "anm";
} else if (buttonClicked.equals("doc")) {
userType = "doc";
} else if (buttonClicked.equals("sdm")) {
userType = "sdm";
}
}
usernameEditText = (EditText) findViewById(R.id.username);
inputPassword = (EditText) findViewById(R.id.password);
btnLogin = (Button) findViewById(R.id.login);
btnLinkToRegister = (Button) findViewById(R.id.register);
// Progress dialog
pDialog = new ProgressDialog(this);
pDialog.setCancelable(false);
}
public void loginCLick(View view) throws SocketException {
Log.i(TAG, "entered login");
String username = usernameEditText.getText().toString().trim();
String ashaphno = username;
String password = inputPassword.getText().toString().trim();
// Check for empty data in the form
if (!ashaphno.isEmpty() && !password.isEmpty()) {
chkStatus();
// login user
checkLogin(ashaphno, password);
Log.i(TAG, "username(ashaphone)" + username);
Intent i;
}
}
// Link to Register Screen
public void clickregister(View view) {
Intent i = new Intent(getApplicationContext(),
AshaRegisterActivity.class);
startActivity(i);
finish();
}
/**
* function to verify login details in mysql db
*/
public void checkLogin(final String ashaphno, final String password) {
// Tag used to cancel the request
String tag_string_req = "req_login";
pDialog.setMessage("Logging in ...");
pDialog.show();
StringRequest strReq = new StringRequest(Request.Method.POST,
Constants.URL_LOGIN, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.d(TAG, "Login Response: " + response.toString());
pDialog.dismiss();
try {
JSONObject jsonObject = new JSONObject(response.substring(response.indexOf("{"), response.lastIndexOf("}") + 1));
boolean error = jsonObject.getBoolean("error");
// Check for error node in json
if (!error) {
// user successfully logged in
// Create login session
Log.i(TAG, "loginactivity" + userType);
if (userType.equals("asha")) {
JSONObject asha = jsonObject.getJSONObject("asha");
String username = asha.getString("AshaUsername");
String phone = asha.getString("Ashaphno");
if (username.equals(phone)) {
// Launch main activity
Intent intent = new Intent(LoginActivitywithConnection.this,
LoginOpeningPageAsha.class);
Bundle b = new Bundle();
b.putString("username", ashaphno);
intent.putExtras(b);
startActivity(intent);
finish();
}
} else if
(userType.equals("anm")) {
Intent i;
i = new Intent(LoginActivitywithConnection.this, LoginOpeningPageANM.class);
Bundle b = new Bundle();
b.putString("username", ashaphno);
i.putExtras(b);
startActivity(i);
}
} else {
// Error in login. Get the error message
String errorMsg = jsonObject.getString("message");
Toast.makeText(getApplicationContext(),
errorMsg, Toast.LENGTH_LONG).show();
Log.i(TAG, "error" +
errorMsg);
}
} catch (JSONException e) {
// JSON error
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Json error: " + e.getMessage(), Toast.LENGTH_LONG).show();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError volleyError) {
Log.e(TAG, "Login Error: " + volleyError.getMessage());
String message = null;
if (volleyError instanceof NetworkError) {
message = "Cannot connect to Internet...Please check your connection!";
} else if (volleyError instanceof ServerError) {
message = "The server could not be found. Please try again after some time!!";
} else if (volleyError instanceof AuthFailureError) {
message = "Cannot connect to Internet...Please check your connection!";
} else if (volleyError instanceof ParseError) {
message = "Parsing error! Please try again after some time!!";
} else if (volleyError instanceof NoConnectionError) {
message = "Cannot connect to Internet...Please check your connection!";
} else if (volleyError instanceof TimeoutError) {
message = "Connection TimeOut! Please check your internet connection.";
}
Toast.makeText(getApplicationContext(),
message, Toast.LENGTH_LONG).show();
String erroridentifier = handleServerError(volleyError, getApplicationContext());
Log.e(TAG, "Login Erroridentifier: " + erroridentifier);
hideDialog();
}
}) {
#Override
protected Map<String, String> getParams() {
// Posting parameters to login url
Map<String, String> params = new HashMap<String, String>();
params.put("AshaUsername", ashaphno);
params.put("ASHApwd", password);
return params;
}
};
DefaultRetryPolicy retryPolicy = new DefaultRetryPolicy(0, -1, DefaultRetryPolicy.DEFAULT_BACKOFF_MULT);
strReq.setRetryPolicy(retryPolicy);
// Adding request to request queue
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
}
Constants Class :
public class Constants {
private static final String ROOT_URL ="http://192.168.43.6/Android/v1/";
// Server user login url
public static String URL_LOGIN = ROOT_URL+"ashaLogin.php";
}
When this apk is downloaded by a user , what will be the server URL(not local) ?

I will be the same URL server, if you what to make work the apk wherever it execute, you should create a public server. Azure, Google, etc, or an server with public IP.

I assume you are using some localhost and serving your PHP code to implement authentication, before releasing your android app into stores like GooglePlay you should first deploy your backend code into some servers like Azure, Digital ocean,... and after deployment and running your backend code on some server you should enter your backend's URL into your app. also I recommend you using Retrofit for your networking stuff it will decrease much of stuff you should deal with.

posting data to mysql database using rest api which is done in magento 2 from my android app?

facing problem in posting data to mysql database using rest api which is done in magento 2 from my android app.
RegisterActivity extends AppCompatActivity {
private static final String TAG = "RegisterActivity";
private static final String URL_FOR_REGISTRATION = "https://xyz/restapi/registration";
ProgressDialog progressDialog;
private EditText signupInputName, signupInputEmail, signupInputPassword, signupInputCnfPassword, signupInputAge;
private Button btnSignUp;
private Button btnLinkLogin;
private RadioGroup genderRadioGroup;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
// Progress dialog
progressDialog = new ProgressDialog(this);
progressDialog.setCancelable(false);
signupInputName = (EditText) findViewById(R.id.signup_input_name);
signupInputEmail = (EditText) findViewById(R.id.signup_input_email);
signupInputPassword = (EditText) findViewById(R.id.signup_input_password);
signupInputCnfPassword = (EditText) findViewById(R.id.signup_input_passwords);
signupInputAge = (EditText) findViewById(R.id.signup_input_age);
btnSignUp = (Button) findViewById(R.id.btn_signup);
btnLinkLogin = (Button) findViewById(R.id.btn_link_login);
btnSignUp.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
submitForm();
}
});
btnLinkLogin.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent i = new Intent(getApplicationContext(),LoginActivity.class);
startActivity(i);
}
});
}
private void submitForm() {
registerUser(signupInputName.getText().toString(),
signupInputEmail.getText().toString(),
signupInputPassword.getText().toString(),
signupInputCnfPassword.getText().toString(),
signupInputAge.getText().toString());
}
private void registerUser(final String name, final String email, final String password, final String cnfpassword, final String dob) {
// Tag used to cancel the request
String cancel_req_tag = "register";
progressDialog.setMessage("Adding you ...");
showDialog();
StringRequest strReq = new StringRequest(Request.Method.POST,
URL_FOR_REGISTRATION, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.d(TAG, "Register Response: " + response.toString());
hideDialog();
try {
JSONObject jObj = new JSONObject(response);
boolean error = jObj.getBoolean("error");
if (!error) {
String user = jObj.getJSONObject("user").getString("name");
Toast.makeText(getApplicationContext(), "Hi " + user +", You are successfully Added!", Toast.LENGTH_SHORT).show();
// Launch login activity
Intent intent = new Intent(
RegisterActivity.this,
LoginActivity.class);
startActivity(intent);
finish();
} else {
String errorMsg = jObj.getString("error_msg");
Toast.makeText(getApplicationContext(),
errorMsg, Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "Registration Error: " + error.getMessage());
Toast.makeText(getApplicationContext(),
error.getMessage(), Toast.LENGTH_LONG).show();
hideDialog();
}
}) {
#Override
protected Map<String, String> getParams() {
// Posting params to register url
Map<String, String> params = new HashMap<String, String>();
params.put("cust_username", name);
params.put("cust_firstname", email);
params.put("cust_pass", password);
params.put("cust_confirmpass", cnfpassword);
params.put("cust_phoneno", dob);
return params;
}
};
// Adding request to request queue
AppSingleton.getInstance(getApplicationContext()).addToRequestQueue(strReq, cancel_req_tag);
}
private void showDialog() {
if (!progressDialog.isShowing())
progressDialog.show();
}
private void hideDialog() {
if (progressDialog.isShowing())
progressDialog.dismiss();
}
}
I am using Volley library for request.
I am getting this error
BasicNetwork.performRequest: Unexpected response code 503 for
https://xyz/restapi/registration.
My question is am I missing any thing or will there be constrain that should be checked in mysql to post the data.

What is the probleme please ? [duplicate]

This question already has answers here:
How do I compare strings in Java?
(23 answers)
Closed 6 years ago.
this is all the code
public class LoginActivity extends Activity {
private static final String TAG = RegisterActivity.class.getSimpleName();
private Button btnLogin;
private Button btnLinkToRegister;
private EditText inputEmail;
private EditText inputPassword;
private ProgressDialog pDialog;
private SessionManager session;
private SQLiteHandler db;
String CK="admin";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
inputEmail = (EditText) findViewById(R.id.email);
inputPassword = (EditText) findViewById(R.id.password);
btnLogin = (Button) findViewById(R.id.btnLogin);
btnLinkToRegister = (Button) findViewById(R.id.btnLinkToRegisterScreen);
// Progress dialog
pDialog = new ProgressDialog(this);
pDialog.setCancelable(false);
// SQLite database handler
db = new SQLiteHandler(getApplicationContext());
// Session manager
session = new SessionManager(getApplicationContext());
// Check if user is already logged in or not
if (session.isLoggedIn()) {
// User is already logged in. Take him to main activity
Intent intent = new Intent(LoginActivity.this, MainActivity.class);
startActivity(intent);
finish();
}
// Login button Click Event
btnLogin.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
String email = inputEmail.getText().toString().trim();
String password = inputPassword.getText().toString().trim();
// Check for empty data in the form
if (!email.isEmpty() && !password.isEmpty()) {
// login user
checkLogin(email, password);
} else {
// Prompt user to enter credentials
Toast.makeText(getApplicationContext(),
"Please enter the credentials!", Toast.LENGTH_LONG)
.show();
}
}
});
// Link to Register Screen
btnLinkToRegister.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent i = new Intent(getApplicationContext(),
RegisterActivity.class);
startActivity(i);
finish();
}
});
}
/**
* function to verify login details in mysql db
* */
private void checkLogin(final String email, final String password) {
// Tag used to cancel the request
String tag_string_req = "req_login";
pDialog.setMessage("Logging in ...");
showDialog();
StringRequest strReq = new StringRequest(Method.POST,
AppConfig.URL_LOGIN, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.d(TAG, "Login Response: " + response.toString());
hideDialog();
try {
JSONObject jObj = new JSONObject(response);
boolean error = jObj.getBoolean("error");
// Check for error node in json
if (!error) {
// user successfully logged in
// Create login session
session.setLogin(true);
My problem is here, i'm using if(!(CK==uid)) it works but when CK==uid it doesn't work , String CK= admin and when i login with admin not a simple user the uid=admin too . i used Log.e to verify you can see my capture image
you can see that CK and uid are the same but when i use (if CK==uid) it doesn't work
// Now store the user in SQLite
String uid = jObj.getString("uid");
JSONObject user = jObj.getJSONObject("user");
String name = user.getString("name");
String email = user.getString("email");
String created_at = user
.getString("created_at");
// Inserting row in users table
db.addUser(name, email, uid, created_at);
Log.e(TAG,"CK: " + CK + " user uid: " + uid);
// Launch main activity
if(!(CK==uid)){
Intent intent = new Intent(LoginActivity.this,
MainActivity.class);
startActivity(intent);
finish();
} else{
Intent i = new Intent(getApplicationContext(), AllReclamationsActivity.class);
startActivity(i);
finish();
}
} else {
// Error in login. Get the error message
String errorMsg = jObj.getString("error_msg");
Toast.makeText(getApplicationContext(),
errorMsg, Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
// JSON error
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Json error: " + e.getMessage(), Toast.LENGTH_LONG).show();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "Login Error: " + error.getMessage());
Toast.makeText(getApplicationContext(),
error.getMessage(), Toast.LENGTH_LONG).show();
hideDialog();
}
}) {
#Override
protected Map<String, String> getParams() {
// Posting parameters to login url
Map<String, String> params = new HashMap<String, String>();
params.put("email", email);
params.put("password", password);
return params;
}
};
// Adding request to request queue
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
}
my problem is in this part :
// Now store the user in SQLite
String uid = jObj.getString("uid");
JSONObject user = jObj.getJSONObject("user");
String name = user.getString("name");
String email = user.getString("email");
String created_at = user
.getString("created_at");
// Inserting row in users table
db.addUser(name, email, uid, created_at);
Log.e(TAG,"CK: " + CK + " user uid: " + uid);
// Launch main activity
if(!(CK==uid)){
Intent intent = new Intent(LoginActivity.this,
MainActivity.class);
startActivity(intent);
finish();
} else{
Intent i = new Intent(getApplicationContext(), AllReclamationsActivity.class);
startActivity(i);
finish();
}

This not a integer value its a string so compare it like as
Use the below function in your condition:
if(!(CK.equals(uid))){
Intent intent = new Intent(LoginActivity.this,
MainActivity.class);
startActivity(intent);
finish();
}

User Login credential doesn't show up in the landing page(Homepage) after logging in

I got user-login template from github. I modified it a bit to suit my need but didn't altered any important code.
Problem 1: If I register and login, the page goes to activity_main class(landing page) and my login credentials(name & email) are shown. But if I log out and logging again the credentials are not shown on the landing page. First time it shows next time never.
Problem 2: If I register a new ID but login with any old already registered ID (immediately after registering new), landing page shows the credential of newly register ID. After that again it won't show up if I log in with any ID.
What I want to Happen: User credential to be shown on landing page whenever he logs in.Also prob 2nd to be fixed.
Any help would be appreciated guys.
login page code:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
inputEmail = (EditText) findViewById(R.id.email);
inputPassword = (EditText) findViewById(R.id.password);
btnLogin = (Button) findViewById(R.id.btnLogin);
btnLinkToRegister = (Button) findViewById(R.id.btnLinkToRegisterScreen);
// Progress dialog
pDialog = new ProgressDialog(this);
pDialog.setCancelable(false);
// Session manager
session = new SessionManager(getApplicationContext());
// Check if user is already logged in or not
if (session.isLoggedIn()) {
// User is already logged in. Take him to main activity
Intent intent = new Intent(Activity_Login.this, Activity_Main.class);
startActivity(intent);
finish();
}
// Login button Click Event
btnLogin.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
String email = inputEmail.getText().toString();
String password = inputPassword.getText().toString();
// Check for empty data in the form
if (email.trim().length() > 0 && password.trim().length() > 0) {
// login user
checkLogin(email, password);
} else {
// Prompt user to enter credentials
Toast.makeText(getApplicationContext(),
"Please enter the credentials!", Toast.LENGTH_LONG)
.show();
}
}
});
// Link to Register Screen
btnLinkToRegister.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent i = new Intent(getApplicationContext(),
Activity_Register.class);
startActivity(i);
finish();
}
});
}
/**
* function to verify login details in mysql db
* */
private void checkLogin(final String email, final String password) {
// Tag used to cancel the request
String tag_string_req = "req_login";
pDialog.setMessage("Logging in ...");
showDialog();
StringRequest strReq = new StringRequest(Method.POST,
Config_URL.URL_REGISTER, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.d(TAG, "Login Response: " + response.toString());
hideDialog();
try {
JSONObject jObj = new JSONObject(response);
boolean error = jObj.getBoolean("error");
// Check for error node in json
if (!error) {
// user successfully logged in
// Create login session
session.setLogin(true);
// Launch main activity
Intent intent = new Intent(Activity_Login.this,
Activity_Main.class);
startActivity(intent);
finish();
} else {
// Error in login. Get the error message
String errorMsg = jObj.getString("error_msg");
Toast.makeText(getApplicationContext(),
errorMsg, Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
// JSON error
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "Login Error: " + error.getMessage());
Toast.makeText(getApplicationContext(),
error.getMessage(), Toast.LENGTH_LONG).show();
hideDialog();
}
}) {
#Override
protected Map<String, String> getParams() {
// Posting parameters to login url
Map<String, String> params = new HashMap<String, String>();
params.put("tag", "login");
params.put("email", email);
params.put("password", password);
return params;
}
};
// Adding request to request queue
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
}
private void showDialog() {
if (!pDialog.isShowing())
pDialog.show();
}
private void hideDialog() {
if (pDialog.isShowing())
pDialog.dismiss();
}
}
Register page code:
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
inputFullName = (EditText) findViewById(R.id.name);
inputEmail = (EditText) findViewById(R.id.email);
inputPassword = (EditText) findViewById(R.id.password);
inputNumber = (EditText) findViewById(R.id.number);
btnRegister = (Button) findViewById(R.id.btnRegister);
btnLinkToLogin = (Button) findViewById(R.id.btnLinkToLoginScreen);
// Progress dialog
pDialog = new ProgressDialog(this);
pDialog.setCancelable(false);
// Session manager
session = new SessionManager(getApplicationContext());
// SQLite database handler
db = new SQLiteHandler(getApplicationContext());
// Check if user is already logged in or not
if (session.isLoggedIn()) {
// User is already logged in. Take him to main activity
Intent intent = new Intent(Activity_Register.this,
Activity_Main.class);
startActivity(intent);
finish();
}
// Register Button Click event
btnRegister.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
String name = inputFullName.getText().toString();
String email = inputEmail.getText().toString();
String password = inputPassword.getText().toString();
String number = inputNumber.getText().toString();
if (!name.isEmpty() && !email.isEmpty() && !password.isEmpty() && !number.isEmpty()) {
registerUser(name, email, password, number);
} else {
Toast.makeText(getApplicationContext(),
"Please enter your details!", Toast.LENGTH_LONG)
.show();
}
}
});
// Link to Login Screen
btnLinkToLogin.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent i = new Intent(getApplicationContext(),
Activity_Login.class);
startActivity(i);
finish();
}
});
}
/**
* Function to store user in MySQL database will post params(tag, name,
* email, password) to register url
* */
private void registerUser(final String name, final String email,
final String password, final String number) {
// Tag used to cancel the request
String tag_string_req = "req_register";
pDialog.setMessage("Registering ...");
showDialog();
StringRequest strReq = new StringRequest(Method.POST,
Config_URL.URL_REGISTER, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.d(TAG, "Register Response: " + response.toString());
hideDialog();
try {
JSONObject jObj = new JSONObject(response);
boolean error = jObj.getBoolean("error");
if (!error) {
// User successfully stored in MySQL
// Now store the user in sqlite
String uid = jObj.getString("uid");
JSONObject user = jObj.getJSONObject("user");
String name = user.getString("name");
String email = user.getString("email");
String created_at = user
.getString("created_at");
// Inserting row in users table
db.addUser(name, email, uid, created_at);
// Launch login activity
Intent intent = new Intent(
Activity_Register.this,
Activity_Login.class);
startActivity(intent);
finish();
} else {
// Error occurred in registration. Get the error
// message
String errorMsg = jObj.getString("error_msg");
Toast.makeText(getApplicationContext(),
errorMsg, Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "Registration Error: " + error.getMessage());
Toast.makeText(getApplicationContext(),
error.getMessage(), Toast.LENGTH_LONG).show();
hideDialog();
}
}) {
#Override
protected Map<String, String> getParams() {
// Posting params to register url
Map<String, String> params = new HashMap<String, String>();
params.put("tag", "register");
params.put("name", name);
params.put("email", email);
params.put("password", password);
params.put("number", number);
return params;
}
};
// Adding request to request queue
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
}
private void showDialog() {
if (!pDialog.isShowing())
pDialog.show();
}
private void hideDialog() {
if (pDialog.isShowing())
pDialog.dismiss();
}
}
Main activity page code:
public class Activity_Main extends Activity {
private TextView txtName;
private TextView txtEmail;
private Button btnLogout;
private SQLiteHandler db;
private SessionManager session;
public Button booknow;
public void init(){
booknow= (Button) findViewById(R.id.booknow);
booknow.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent toy = new Intent(Activity_Main.this,BikeEntryActivity.class);
startActivity(toy);
}
});
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
init();
txtName = (TextView) findViewById(R.id.name);
txtEmail = (TextView) findViewById(R.id.email);
btnLogout = (Button) findViewById(R.id.btnLogout);
// SqLite database handler
db = new SQLiteHandler(getApplicationContext());
// session manager
session = new SessionManager(getApplicationContext());
if (!session.isLoggedIn()) {
logoutUser();
}
// Fetching user details from sqlite
HashMap<String, String> user = db.getUserDetails();
String name = user.get("name");
String email = user.get("email");
// Displaying the user details on the screen
txtName.setText(name);
txtEmail.setText(email);
// Logout button click event
btnLogout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
logoutUser();
}
});
}
/**
* Logging out the user. Will set isLoggedIn flag to false in shared
* preferences Clears the user data from sqlite users table
* */
private void logoutUser() {
session.setLogin(false);
db.deleteUsers();
// Launching the login activity
Intent intent = new Intent(Activity_Main.this, Activity_Login.class);
startActivity(intent);
finish();
}
}

For problem 1, when you logout, you are deleting users by calling db.deleteUsers();
When you login again, you need to call db.addUser(name, email, uid, created_at); as you did for registration.
The same applies for problem 2.
UPDATE:
....
if (!error) {
// user successfully logged in
// Create login session
session.setLogin(true);
//You need to save the user here before launching main activity.
db.addUser(name,email);//or whatever method you use to save user.
// Launch main activity
Intent intent = new Intent(Activity_Login.this,
Activity_Main.class);
startActivity(intent);
finish();
}

why its showing nullpointerexception? [duplicate]

This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 7 years ago.
I know this is a really common topic but I'm getting this error and don't know why. The code is working absolutely fine in Eclipse but crashing on Button click in Studio. The only difference I can think of is Request.Method instead of Method as in Eclipse. Earlier I thought its because, the values from edittext are not getting. But its showing in Toast.
Error
01-13 11:13:34.242 14427-14427/com.sam.sports E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.sam.sports, PID: 14427
java.lang.NullPointerException
at com.sam.sports.LoginPage.checkLogin(LoginPage.java:180)
at com.sam.sports.LoginPage.access$200(LoginPage.java:28)
at com.sam.sports.LoginPage$1.onClick(LoginPage.java:80)
at android.view.View.performClick(View.java:4562)
at android.view.View$PerformClick.run(View.java:18918)
at android.os.Handler.handleCallback(Handler.java:808)
at android.os.Handler.dispatchMessage(Handler.java:103)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:5388)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:655)
at dalvik.system.NativeStart.main(Native Method)
01-13 11:13:38.996 14427-14427/com.sam.sports I/Process: Sending signal. PID: 14427 SIG: 9
public class LoginPage extends AppCompatActivity {
private static final String TAG = RegisterPage.class.getSimpleName();
private Button btnLogin;
private Button btnLinkToRegister;
private EditText inputEmail;
private EditText inputPassword;
private ProgressDialog pDialog;
private SessionManager session;
private SQLiteHandler db;
String name;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.loginpage);
inputEmail = (EditText) findViewById(R.id.email_login);
inputPassword = (EditText) findViewById(R.id.password_login);
btnLogin = (Button) findViewById(R.id.login_btn);
btnLinkToRegister = (Button) findViewById(R.id.btnLinktoRegd);
// Progress dialog
pDialog = new ProgressDialog(this);
pDialog.setCancelable(false);
// SQLite database handler
db = new SQLiteHandler(getApplicationContext());
// Session manager
session = new SessionManager(getApplicationContext());
// Check if user is already logged in or not
if (session.isLoggedIn()) {
// User is already logged in. Take him to main activity
Intent intent = new Intent(LoginPage.this, HomePage.class);
startActivity(intent);
finish();
}
// Login button Click Event
btnLogin.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
String email = inputEmail.getText().toString().trim();
String password = inputPassword.getText().toString().trim();
// Check for empty data in the form
if (!email.isEmpty() && !password.isEmpty()) {
// login user
checkLogin(email, password);
//Toast.makeText(getApplicationContext(), email + "\n" + password, Toast.LENGTH_LONG ).show();
} else {
// Prompt user to enter credentials
Toast.makeText(getApplicationContext(), "Please enter the credentials!", Toast.LENGTH_LONG).show();
}
}
});
// Link to Register Screen
btnLinkToRegister.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
startActivity(new Intent(LoginPage.this, RegisterPage.class));
finish();
}
});
}
/**
* function to verify login details in mysql db
* */
private void checkLogin(final String email, final String password) {
// Tag used to cancel the request
String tag_string_req = "req_login";
pDialog.setMessage("Logging in ...");
showDialog();
StringRequest strReq = new StringRequest(Request.Method.POST,
AppConfig.URL_LOGIN, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.d(TAG, "Login Response: " + response.toString());
hideDialog();
try {
JSONObject jObj = new JSONObject(response);
String status = jObj.getString("status");
// Now check status value
if (status.equals("0")) {
Toast.makeText(getApplicationContext(), "Email or Password may be incorrect! Please try again.", Toast.LENGTH_LONG).show();
}else if(status.equals("1")){
// user successfully logged in
// Create login session
session.setLogin(true);
// Now store the user in SQLite
JSONObject userData = jObj.getJSONObject("userData");
String uid = userData.getString("id");
String name = userData.getString("name");
String email = userData.getString("email");
String created_at = userData.getString("created_at");
// Inserting row in users table
db.addUser(name, email, uid, created_at);
// Launch main activity
startActivity(new Intent(LoginPage.this, HomePage.class));
finish();
} else {
// Error in login. Get the error message
String errorMsg = jObj.getString("error_msg");
Toast.makeText(getApplicationContext(), errorMsg, Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
// JSON error
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Json error: " + e.getMessage(), Toast.LENGTH_LONG).show();
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "Login Error: " + error.getMessage());
Toast.makeText(getApplicationContext(), error.getMessage(), Toast.LENGTH_LONG).show();
hideDialog();
}
}) {
#Override
protected Map<String, String> getParams() {
// Posting parameters to login url
Map<String, String> params = new HashMap<String, String>();
params.put("email", email);
params.put("password", password);
return params;
}
};
// Adding request to request queue
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
}
private void showDialog() {
if (!pDialog.isShowing())
pDialog.show();
}
private void hideDialog() {
if (pDialog.isShowing())
pDialog.dismiss();
}
}

Although this is not a solution to your problem(for solution look below), refactoring the checkLogin Method will definetly help alot in finding the cause of the error. Due to the fact that the checkLogin method was way to long I've move some of the code into other methods.
Copy it, run it and let us know which line throws the error.
/**
* function to verify login details in mysql db
* */
private void checkLogin(final String email, final String password) {
// Tag used to cancel the request
String tag_string_req = "req_login";
pDialog.setMessage("Logging in ...");
showDialog();
StringRequest strReq = new StringRequest(Request.Method.POST,
AppConfig.URL_LOGIN, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.d(TAG, "Login Response: " + response.toString());
hideDialog();
checkStatus();
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.e(TAG, "Login Error: " + error.getMessage());
Toast.makeText(getApplicationContext(), error.getMessage(), Toast.LENGTH_LONG).show();
hideDialog();
}
}) {
#Override
protected Map<String, String> getParams() {
// Posting parameters to login url
Map<String, String> params = new HashMap<String, String>();
params.put("email", email);
params.put("password", password);
return params;
}
};
// Adding request to request queue
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
}
private void checkStatus() {
try {
JSONObject jObj = new JSONObject(response);
String status = jObj.getString("status");
// Now check status value
if (status.equals("0")) {
processStatusZero();
}else if(status.equals("1")){
processStatusOne(jObj);
} else {
processStatusError(jObj);
}
} catch (JSONException e) {
// JSON error
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Json error: " + e.getMessage(), Toast.LENGTH_LONG).show();
}
}
private void processStatusZero() {
Toast.makeText(getApplicationContext(), "Email or Password may be incorrect! Please try again.", Toast.LENGTH_LONG).show();
}
private void processStatusOne(JSONObject jObj) {
// user successfully logged in
// Create login session
session.setLogin(true);
// Now store the user in SQLite
JSONObject userData = jObj.getJSONObject("userData");
String uid = userData.getString("id");
String name = userData.getString("name");
String email = userData.getString("email");
String created_at = userData.getString("created_at");
// Inserting row in users table
db.addUser(name, email, uid, created_at);
// Launch main activity
startActivity(new Intent(LoginPage.this, HomePage.class));
finish();
}
private void processStatusError(JSONObject jObj) {
// Error in login. Get the error message
String errorMsg = jObj.getString("error_msg");
Toast.makeText(getApplicationContext(), errorMsg, Toast.LENGTH_LONG).show();
}
Now for the actual solution: you need to add AppControler to the Android Manifest. You do this by adding the following lines in your manifest file:
<application
android:name=".AppController"
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme">
This way AppController.getInstance() will stop returning null.