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.

The app works on emulator but not on actual device

I just wanted help in my android app actually scene is like ,I have made an android app that stores and fetch data from mysql database,so the twist is whenever I run app on android emulator it runs fine but as soon as I try to run it on actual device there seem to be nothing is happening however the login and register buttons seem to be doing nothing they don't call the api,I am using wamp as local server and my device and laptop is on same wifi network router so I am not getting it,btw the logcat shows no error at all and it also runs perfectly on emulator
my register activity to add user into database
public class Register extends AppCompatActivity {
private static final String TAG = Register.class.getSimpleName();
ProgressDialog progressDialog;
private EditText signupInputName, signupInputEmail, signupInputPassword;
public Button btnSignUp;
public Button btnLinkLogin;
private SQLiteHandler db;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
progressDialog = new ProgressDialog(this);
progressDialog.setCancelable(false);
SessionManager session = new SessionManager(getApplicationContext());
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(Register.this,
Matchboard.class);
startActivity(intent);
finish();
}
signupInputName = (EditText) findViewById(R.id.name);
signupInputEmail = (EditText) findViewById(R.id.email);
signupInputPassword = (EditText) findViewById(R.id.password);
btnSignUp = (Button) findViewById(R.id.btnRegister);
btnLinkLogin = (Button) findViewById(R.id.btnLinkToLoginScreen);
btnSignUp.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String name = signupInputName.getText().toString().trim();
String email = signupInputEmail.getText().toString().trim();
String password = signupInputPassword.getText().toString().trim();
if (!name.isEmpty() && !email.isEmpty() && !password.isEmpty()) {
registerUser(name, email, password);
} else {
Toast.makeText(getApplicationContext(),
"Please enter your details!", Toast.LENGTH_SHORT).show();
}
}
});
btnLinkLogin.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent i = new Intent(getApplicationContext(),Login.class);
startActivity(i);
finish();
}
});
}
private void registerUser(final String name, final String email, final String password) {
// Tag used to cancel the request
String tag_string_req = "req_register";
progressDialog.setMessage("Adding you ...");
showDialog();
StringRequest strReq = new StringRequest(Request.Method.POST,
AppConfig.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) {
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);
Toast.makeText(getApplicationContext(), "Hi "+name+",You are successfully Added!", Toast.LENGTH_SHORT).show();
// Launch login activity
Intent intent = new Intent(
Register.this,
Login.class);
startActivity(intent);
finish();
} else {
String errorMsg = jObj.getString("error_msg");
Toast.makeText(getApplicationContext(),
errorMsg, Toast.LENGTH_SHORT).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_SHORT).show();
hideDialog();
}
}) {
#Override
protected Map<String, String> getParams() {
// Posting params to register url
Map<String, String> params = new HashMap<String, String>();
params.put("name", name);
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 (!progressDialog.isShowing())
progressDialog.show();
}
private void hideDialog() {
if (progressDialog.isShowing())
progressDialog.dismiss();
}
}

I believe when you are on your local machine the call to made to the localhost but when the app is on your actual device there might be some IP issue.You might be accessing it wrongly.
The thing is that your actual device and the system should be on the same network.
Check your IP using ipconfig command and then retry on same network.

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();
}

Registration and Login

Im using a tutorial from http://www.androidhive.info/2012/01/android-login-and-registration-with-php-mysql-and-sqlite/
when i click the Login or Register button the app crashes instantly with a null ponter exception. LogCat is pointing me to 3 lines in the code(Login.java). Any ideas on how to fix this?
loginCheck(email, password);
private void loginCheck(final String email, final String password) {
and
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
LogCat
E/AndroidRuntime(6911): java.lang.NullPointerException
E/AndroidRuntime(6911): at com.smwale.zicaresults1.Login.loginCheck(Login.java:176)
E/AndroidRuntime(6911): at com.smwale.zicaresults1.Login.access$2(Login.java:108)
E/AndroidRuntime(6911): at com.smwale.zicaresults1.Login$1.onClick(Login.java:85)
E/AndroidRuntime(6911): at android.view.View.performClick(View.java:3511)
E/AndroidRuntime(6911): at android.view.View$PerformClick.run(View.java:14105)
E/AndroidRuntime(6911): at android.os.Handler.handleCallback(Handler.java:605)
E/AndroidRuntime(6911): at android.os.Handler.dispatchMessage(Handler.java:92)
E/AndroidRuntime(6911): at android.os.Looper.loop(Looper.java:137)
E/AndroidRuntime(6911): at android.app.ActivityThread.main(ActivityThread.java:4424)
E/AndroidRuntime(6911): at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime(6911): at java.lang.reflect.Method.invoke(Method.java:511)
E/AndroidRuntime(6911): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
E/AndroidRuntime(6911): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
E/AndroidRuntime(6911): at dalvik.system.NativeStart.main(Native Method)
Login,java
public class Login extends Activity{
// LogCat tag
private static final String TAG = Register.class.getSimpleName();
private Button buttonLogin;
private Button btnLinkToRegister;
private EditText emailInput;
private EditText passwordInput;
private ProgressDialog pDialog;
private SessionManager session;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView (R.layout.activity_login);
emailInput = (EditText)findViewById(R.id.etLoginEmail);
passwordInput = (EditText)findViewById(R.id.etLoginPass);
buttonLogin = (Button)findViewById(R.id.buttonLogin);
btnLinkToRegister = (Button)findViewById(R.id.buttonToReg);
//p dialog
pDialog = new ProgressDialog(this);
pDialog.setCancelable(false);
//sessionMan
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(Login.this, HomeActivity.class);
startActivity(intent);
finish();
}
buttonLogin.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String email = emailInput.getText().toString();
String password = passwordInput.getText().toString();
// Check for empty data in the form
if (email.trim().length() > 0 && password.trim().length() > 0) {
// login user
loginCheck(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(),
Register.class);
startActivity(i);
finish();
}
});
}
private void loginCheck(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_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(Login.this,
HomeActivity.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();
}
private void actionBarSetup() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
ActionBar ab = getActionBar();
ab.setTitle("My Results");
ab.setSubtitle("Login screen");
}
}}

Joshua
I faced the same problem.Found that "AppController.getInstance()" is returning NULL.
May be you missed
android:name="info.androidhive.loginandregistration.app.AppController" in the manifest file