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Error occurred while the connection of registration API by through PHP in android

I try to connect Login and Registration form through PHP API, But I get the error and I don't understand how its will be resolve. I check the solution regarding this error but I don't understand it. Thank you in advance!
Error :-
W/System.err: org.json.JSONException: Value null of type org.json.JSONObject$1 cannot be converted to JSONObject
Here is my code for Registration form (Login.java)
Login. java (This is the java file where for Registration)
public class Login extends Activity {
EditText editname, editemail, editpassword, editmobile;
Button btnRegister;
private static final String TAG = "Login";
private static final String URL_FOR_REGISTRATION = "http://codexpertise.com/codexpertise.com/apitest/signup.php";
ProgressDialog progressDialog;
ImageButton btnfb;
#Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_registration);
// Progress dialog
progressDialog = new ProgressDialog(this);
progressDialog.setCancelable(false);
editname = (EditText) findViewById(R.id.editname);
editemail = (EditText) findViewById(R.id.editemail);
editpassword = (EditText) findViewById(R.id.editpassword);
editmobile = (EditText) findViewById(R.id.editmobile);
btnRegister = (Button) findViewById(R.id.btnRegister);
btnfb = (ImageButton)findViewById(R.id.btnfb);
btnRegister.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
submitForm();
}
private void submitForm() {
registerUser(editname.getText().toString(),
editemail.getText().toString(),
editpassword.getText().toString(),
editmobile.getText().toString());
}
private void registerUser(final String name, final String email, final String password,
final String mobile) {
// 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(
Login.this,
MainActivity.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("name", name);
params.put("email", email);
params.put("password", password);
params.put("gender", mobile);
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();
}
});
btnfb.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Uri uri = Uri.parse("https://www.facebook.com/"); // missing 'http://' will cause crashed
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent);
}
});
}
}
Here is the some image which i test it on postman
[1
Check this
[2

Try this
your response not any boolean error = jObj.getBoolean("error"); so you can read your response code and change your condition as your requirement..
try
{
JSONObject jObj = new JSONObject(response);
String respCode = jObj.getString("resp_code");
//boolean error = jObj.getBoolean("error");
if (respCode.equals("200")) {
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(
Login.this,
MainActivity.class);
startActivity(intent);
finish();
} else {
String errorMsg = jObj.getString("error_msg");
Toast.makeText(getApplicationContext(),
errorMsg, Toast.LENGTH_LONG).show();
}
} catch (JSONException e) {
e.printStackTrace();
}

On back pressed goes to login screen after register

I made an app that requires the user to register. The first time user opens the app - login screen opens. They need to click on the "go to register" button to go to register activity. After they register, they are automatically logged in.
Now here is the issue - when the user first registers he is sent to MainActivity. He should press back and the app should close. But when he tries to exit the app he presses the back button and instead of app closing it goes back to login screen.
The next time I try to sign in, I have no problem - it goes straight to the MainActivity.
This is how my activities look like:
LoginActivity:
public class LoginActivity extends AppCompatActivity {
private static final String TAG = "LoginActivity";
private static final int REQUEST_REGISTER = 0;
#InjectView(R.id.input_email) EditText _emailText;
#InjectView(R.id.input_password) EditText _passwordText;
#InjectView(R.id.btn_login) Button _loginButton;
#InjectView(R.id.link_register) TextView _registerLink;
CheckBox checkBoxShowPassword;
private SessionManager session;
private SQLiteHandler db;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
ButterKnife.inject(this);
// 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();
}
_loginButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String email = _emailText.getText().toString().trim();
String password = _passwordText.getText().toString().trim();
if (!email.isEmpty() && !password.isEmpty()) {
// login user
login(email, password);
} else {
// Prompt user to enter credentials
Toast.makeText(getApplicationContext(),
"Please enter the credentials!", Toast.LENGTH_LONG)
.show();
}
}
});
// Go to register screen
_registerLink.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// Start the Register activity
Intent intent = new Intent(getApplicationContext(), RegisterActivity.class);
startActivityForResult(intent, REQUEST_REGISTER);
}
});
// Password checkbox
checkBoxShowPassword = (CheckBox) findViewById(R.id.checkBoxShowPassword);
checkBoxShowPassword.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
// checkbox status is changed from uncheck to checked.
if (!isChecked) {
// show password
_passwordText.setTransformationMethod(PasswordTransformationMethod.getInstance());
} else {
// hide password
_passwordText.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
}
}
});
}
// Login
public void login(final String email, final String password) {
Log.d(TAG, "Login");
if (!validate()) {
onLoginFailed();
return;
}
// Change to false for disabling after error
_loginButton.setEnabled(true);
String tag_string_req = "req_login";
final ProgressDialog progressDialog = new ProgressDialog(LoginActivity.this,
R.style.AppTheme_Dark_Dialog);
progressDialog.setIndeterminate(true);
progressDialog.setMessage("Authenticating...");
progressDialog.show();
// TODO: Implementing authentication logic
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());
progressDialog.dismiss();
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);
// 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 main activity
Intent intent = new Intent(LoginActivity.this,
MainActivity.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();
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 toast = Toast.makeText(getApplicationContext(),
"Registration failed due to connectivity issues", Toast.LENGTH_LONG);
toast.setGravity(Gravity.CENTER, 0, 0);
toast.show();
// _loginButton.setEnabled(true);
progressDialog.dismiss();
}
}) {
#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);
#Override
public void onBackPressed() {
// disable going back to the MainActivity
moveTaskToBack(true);
}
public void onLoginSuccess() {
_loginButton.setEnabled(true);
finish();
}
public void onLoginFailed() {
Toast.makeText(getBaseContext(), "Login failed", Toast.LENGTH_LONG).show();
_loginButton.setEnabled(true);
}
// Validation
public boolean validate() {
boolean valid = true;
String email = _emailText.getText().toString();
String password = _passwordText.getText().toString();
if (email.isEmpty() || !android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
_emailText.setError("Enter a valid email address");
valid = false;
} else {
_emailText.setError(null);
}
if (password.isEmpty() || password.length() < 4 || password.length() > 20) {
_passwordText.setError("Enter between 4 and 20 alphanumeric characters");
valid = false;
} else {
_passwordText.setError(null);
}
return valid;
}
}
RegisterActivity
public class RegisterActivity extends AppCompatActivity {
private static final String TAG = "RegisterActivity";
#InjectView(R.id.input_name) EditText _nameText;
#InjectView(R.id.input_email) EditText _emailText;
#InjectView(R.id.input_password) EditText _passwordText;
#InjectView(R.id.btn_register) Button _registerButton;
#InjectView(R.id.link_login) TextView _loginLink;
CheckBox checkBoxShowPassword;
private SessionManager session;
private SQLiteHandler db;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
ButterKnife.inject(this);
// 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(RegisterActivity.this,
MainActivity.class);
startActivity(intent);
finish();
}
// Register button
_registerButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String name = _nameText.getText().toString().trim();
String email = _emailText.getText().toString().trim();
String password = _passwordText.getText().toString().trim();
String phone = getMyPhoneNumber();
if (!name.isEmpty() && !email.isEmpty() && !password.isEmpty()) {
register(name, email, password, phone);
} else {
Toast.makeText(getApplicationContext(),
"Please enter your details!", Toast.LENGTH_LONG)
.show();
}
}
});
// Go to login screen
_loginLink.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// Finish the registration screen and return to the Login activity
finish();
}
});
// Password checkbox
checkBoxShowPassword = (CheckBox) findViewById(R.id.checkBoxShowPassword);
checkBoxShowPassword.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
// checkbox status is changed from uncheck to checked.
if (!isChecked) {
// show password
_passwordText.setTransformationMethod(PasswordTransformationMethod.getInstance());
} else {
// hide password
_passwordText.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
}
}
});
}
// Register
public void register(final String name, final String email, final String password, final String phone) {
Log.d(TAG, "Register");
if (!validate()) {
onRegisterFailed();
return;
}
_registerButton.setEnabled(false);
String tag_string_req = "req_register";
final ProgressDialog progressDialog = new ProgressDialog(RegisterActivity.this,
R.style.AppTheme_Dark_Dialog);
progressDialog.setIndeterminate(true);
progressDialog.setMessage("Creating Account...");
progressDialog.show();
// TODO: Implementing register logic
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());
progressDialog.dismiss();
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);
//TODO: insert contacts to local db
String[] PROJECTION = new String[] {
ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME,
ContactsContract.CommonDataKinds.Phone.NUMBER
};
Cursor phones = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, PROJECTION, null, null, null);
while (phones.moveToNext()) {
if (phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER) != -1)
{
String username = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
String phoneNumber = phones.getString(phones.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
db.addContact(username, phoneNumber);
}
}
phones.close();
Toast.makeText(getApplicationContext(), "Registration successful!", Toast.LENGTH_LONG).show();
// Auto login
session.setLogin(true);
// Launch login activity
Intent intent = new Intent(
RegisterActivity.this,
MainActivity.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 toast = Toast.makeText(getApplicationContext(),
"Registration failed due to connectivity issues", Toast.LENGTH_LONG);
toast.setGravity(Gravity.CENTER, 0, 0);
toast.show();
_registerButton.setEnabled(true);
progressDialog.dismiss();
}
}) {
#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);
params.put("phone", phone);
return params;
}
};
// Adding request to request queue
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
}
public void onRegisterSuccess() {
_registerButton.setEnabled(true);
setResult(RESULT_OK, null);
finish();
}
public void onRegisterFailed() {
Toast.makeText(getBaseContext(), "Registration failed", Toast.LENGTH_LONG).show();
_registerButton.setEnabled(true);
}
// Validation
public boolean validate() {
boolean valid = true;
String name = _nameText.getText().toString();
String email = _emailText.getText().toString();
String password = _passwordText.getText().toString();
if (name.isEmpty() || name.length() < 3) {
_nameText.setError("Enter at least 3 characters");
valid = false;
} else {
_nameText.setError(null);
}
if (email.isEmpty() || !android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
_emailText.setError("Enter a valid email address");
valid = false;
} else {
_emailText.setError(null);
}
if (password.isEmpty() || password.length() < 4 || password.length() > 20) {
_passwordText.setError("Enter between 4 and 20 alphanumeric characters");
valid = false;
} else {
_passwordText.setError(null);
}
return valid;
}
// Get users phone number
private String getMyPhoneNumber() {
TelephonyManager tMgr = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
String MyPhoneNumber = "0000000000";
try
{
MyPhoneNumber =tMgr.getLine1Number();
}
catch(NullPointerException ex)
{
}
if(MyPhoneNumber.equals("")){
MyPhoneNumber = tMgr.getSubscriberId();
}
return MyPhoneNumber;
}
private String getMy10DigitPhoneNumber() {
String s = getMyPhoneNumber();
return s.substring(2);
}
}

As per my idea you just do one thing that when you are passing from login activity to register_activity just finish the login_activity like this
// Go to register screen
_registerLink.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// Start the Register activity
Intent intent = new Intent(getApplicationContext(), RegisterActivity.class);
startActivityForResult(intent, REQUEST_REGISTER);
LoginActivity.this.finish();
}
});
If you still facing the same problem then when you are opens the login_activity first then create a variable of that class and assign the value to that variable like this
public static LoginActivity mLogin_activity;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mLogin_activity=LoginActivity.this;
Then check this value is null or not in onBackPressed() method in Main_Activity if that value is null then finish that main_activity otherwise finish that login_activity too; Something like this:
#Override
public void onBackPressed() {
super.onBackPressed();
if (LoginActivity.mLogin_activity!=null) {
LoginActivity.mLogin_activity.finish();
MainActivity.this.finish();
}else {
MainActivity.this.finish();
}
}
Hope i had answered your question...

when you write
Intent intent = new Intent(getApplicationContext(), RegisterActivity.class);
startActivityForResult(intent, REQUEST_REGISTER);
This must need to override onActivityResult method to handle that result.
In that code you just write
Intent intent = new Intent(getApplicationContext(), RegisterActivity.class);
startActivity(intent);
finish();
I hope this could be help you.

For me, I found out that I was calling a variable from another activity which was on my Register.xml (the progressbarBtn) instead of the progressbar that I inserted on Login.Java which was ProgressbarBtn3
thats why it is taking me back to the register page

responsed data not displayed

After Login, I get back a JSON response from the server with the real name of the user. But it won't be displayed in TextView txtName. What is wrong with the code?
MainActivity.java:
public class MainActivity extends Activity {
private TextView txtName;
private TextView txtEmail;
private Button btnLogout;
private Button btnNeu;
private Button btnAlle;
private SQLiteHandler db;
private SessionManager session;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (android.os.Build.VERSION.SDK_INT > 9) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
}
txtName = (TextView) findViewById(R.id.name);
txtEmail = (TextView) findViewById(R.id.email);
btnLogout = (Button) findViewById(R.id.btnLogout);
btnNeu = (Button) findViewById(R.id.neu);
btnAlle = (Button) findViewById(R.id.alle);
// 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);
...
}
private void logoutUser() {
session.setLogin(false);
db.deleteUsers();
Intent intent = new Intent(MainActivity.this, LoginActivity.class);
startActivity(intent);
finish();
}
}
SQLiteHandler.java:
public class SQLiteHandler extends SQLiteOpenHelper {
private static final String TAG = SQLiteHandler.class.getSimpleName();
// All Static variables
// Database Version
private static final int DATABASE_VERSION = 1;
// Database Name
private static final String DATABASE_NAME = "android_api";
// Login table name
private static final String TABLE_LOGIN = "login";
// Login Table Columns names
private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_EMAIL = "email";
private static final String KEY_UID = "uid";
private static final String KEY_CREATED_AT = "created_at";
public SQLiteHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
// Creating Tables
#Override
public void onCreate(SQLiteDatabase db) {
String CREATE_LOGIN_TABLE = "CREATE TABLE " + TABLE_LOGIN + "("
+ KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
+ KEY_EMAIL + " TEXT UNIQUE," + KEY_UID + " TEXT,"
+ KEY_CREATED_AT + " TEXT" + ")";
db.execSQL(CREATE_LOGIN_TABLE);
Log.d(TAG, "Database tables created");
}
// Upgrading database
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// Drop older table if existed
db.execSQL("DROP TABLE IF EXISTS " + TABLE_LOGIN);
// Create tables again
onCreate(db);
}
/**
* Storing user details in database
* */
public void addUser(String name, String email, String uid, String created_at) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, name); // Name
values.put(KEY_EMAIL, email); // Email
values.put(KEY_UID, uid); // Email
values.put(KEY_CREATED_AT, created_at); // Created At
// Inserting Row
long id = db.insert(TABLE_LOGIN, null, values);
db.close(); // Closing database connection
Log.d(TAG, "New user inserted into sqlite: " + id);
}
/**
* Getting user data from database
* */
public HashMap<String, String> getUserDetails() {
HashMap<String, String> user = new HashMap<String, String>();
String selectQuery = "SELECT * FROM " + TABLE_LOGIN;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(selectQuery, null);
// Move to first row
cursor.moveToFirst();
if (cursor.getCount() > 0) {
user.put("name", cursor.getString(1));
user.put("email", cursor.getString(2));
user.put("uid", cursor.getString(3));
user.put("created_at", cursor.getString(4));
}
cursor.close();
db.close();
// return user
Log.d(TAG, "Fetching user from Sqlite: " + user.toString());
return user;
}
/**
* Getting user login status return true if rows are there in table
* */
public int getRowCount() {
String countQuery = "SELECT * FROM " + TABLE_LOGIN;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
int rowCount = cursor.getCount();
db.close();
cursor.close();
// return row count
return rowCount;
}
/**
* Re crate database Delete all tables and create them again
* */
public void deleteUsers() {
SQLiteDatabase db = this.getWritableDatabase();
// Delete All Rows
db.delete(TABLE_LOGIN, null, null);
db.close();
Log.d(TAG, "Deleted all user info from sqlite");
}
}
LoginActivity.java:
public class LoginActivity extends Activity {
// LogCat tag
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;
#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(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();
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(),
"Bitte Benutzername und Passwort eintragen!", 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("Login ...");
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(LoginActivity.this,
MainActivity.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();
}
}

Finally I found the code i have forgotten to insert in LoginActivity.java:
Now it is working
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;
#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);
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();
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(),
"Bitte Benutzername und Passwort eintragen!", 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("Login ...");
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);
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 main activity
Intent intent = new Intent(LoginActivity.this,
MainActivity.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();
}
}

Android login app not logging user in

I am trying to develop a chat application with a login and registration. The app is working without any errors, when I register it adds the right information in SQLite but when i log in with those details the app says "Logging in" but nothing happens. Does anyone know what is wrong with my code?
LoginActivity.java
public class LoginActivity extends Activity {
// LogCat tag
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;
#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(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();
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(),
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_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(LoginActivity.this,
MainActivity.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();
}
}
MainActivity.java
public class MainActivity extends Activity
{
private TextView txtName;
private TextView txtEmail;
private Button btnLogout;
private SQLiteHandler db;
private SessionManager session;
public Socket sender;
public BufferedReader br;
public PrintStream bw;
class SocketListener implements Runnable
{
String str;
public void run()
{
try
{
sender = new Socket("127.0.0.1", 1234);
br = new BufferedReader (new InputStreamReader(sender.getInputStream()));
bw = new PrintStream (sender.getOutputStream());
bw.println("Connected");
while (true)
{
final TextView t = (TextView)findViewById(R.id.textView);
String s = br.readLine ();
CharSequence cs = t.getText ();
str = cs + "\r\n" + s;
Log.i("Chat-str:", str);
t.post(new Runnable()
{
public void run()
{
t.setText(str);
}
}
);
}
}
catch (IOException e)
{
Log.e(getClass().getName(), e.getMessage());
}
}
}
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
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();
}
});
TextView tv = (TextView)findViewById(R.id.textView);
tv.setMovementMethod(new ScrollingMovementMethod());
Button send1 = (Button)findViewById(R.id.button);
send1.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
final EditText et = (EditText)findViewById(R.id.editText);
Editable e = et.getText();
final String s = e.toString();
new Thread ()
{
public void run ()
{
bw.println (s);
}
}.start();
}
});
Thread t = new Thread (new SocketListener ());
t.start();
}
/**
* 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(MainActivity.this, LoginActivity.class);
startActivity(intent);
finish();
}
}

it doesnt look like you ever log them in. look here
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();
}
}
});
what is checkLogin(email, password);
and if it is returning a boolean you should be saying
if(checkLogin){
//log them in
}
can you post the checklogin code?

Getting NullPointerException, but dont understand why

I have this school project where I have to implement a login/register system in an Android app. Now the app is working and I can enter email and password but as soon as I send the data by submitting, the app instantly crashes. I get a NullPointerException, however I can't seem to understand why a null value is passed.
The Android output when the app crashes is:
java.lang.NullPointerException
at com.teamtreehouse.oslist.LoginActivity.checkLogin(LoginActivity.java:163)
at com.teamtreehouse.oslist.LoginActivity.access$200(LoginActivity.java:24)
at com.teamtreehouse.oslist.LoginActivity$1.onClick(LoginActivity.java:69)
at android.view.View.performClick(View.java:4633)
at android.view.View$PerformClick.run(View.java:19330)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:157)
at android.app.ActivityThread.main(ActivityThread.java:5356)
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:1265)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1081)
at dalvik.system.NativeStart.main(Native Method)
LoginActivity.java:
#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(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();
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(),
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_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(LoginActivity.this,
MainActivity.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();
}
}
LoginActivity.java:163 refers to
AppController.getInstance().addToRequestQueue(strReq, tag_string_req);
LoginActivity.java:24 refers to
public class LoginActivity
and LoginActivity.java:69 refers to
checkLogin(email, password);

I'm guessing the instance of AppController is null. Try this:
NullPointerException when using CustomListAdapter