I am using Androids SaveSharedPreference to allow a user to auto login once they already logged in previously. For a user to gain access, their login information must be sent to my server using webscokets, and once a connection is made they will be able to access their accounts.
In terms of present functionality, the users can log into the app the first time and use all the features. The problem arises as the user closes out, not logs out, and attempts to access again and the error below is thrown and the app crashes:
and then
I have seen that the NullPoint error on line 207 of LoggingIn is at:
result = imService.authenticateUser(
SaveSharedPreference
.getUserName(getApplicationContext()),
SaveSharedPreference
.getPassword(getApplicationContext()));
The remaining code of the class in the onCreate method of the LoggingIn class called once app starts:
protected static final int NOT_CONNECTED_TO_SERVICE = 0;
protected static final int FILL_BOTH_USERNAME_AND_PASSWORD = 1;
public static final String AUTHENTICATION_FAILED = "0";
public static final String FRIEND_LIST = "FRIEND_LIST";
protected static final int MAKE_SURE_USERNAME_AND_PASSWORD_CORRECT = 2;
protected static final int NOT_CONNECTED_TO_NETWORK = 3;
private EditText usernameText;
private EditText passwordText;
private Manager imService;
public static final int SIGN_UP_ID = Menu.FIRST;
public static final int EXIT_APP_ID = Menu.FIRST + 1;
private ServiceConnection mConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className, IBinder service) {
// This is called when the connection with the service has been
// established, giving us the service object we can use to
// interact with the service. Because we have bound to a explicit
// service that we know is running in our own process, we can
// cast its IBinder to a concrete class and directly access it.
imService = ((MessagingService.IMBinder) service).getService();
if (imService.isUserAuthenticated() == true) {
// Intent i = new Intent(LoggingIn.this, ListOfFriends.class);
Intent i = new Intent(LoggingIn.this, MainActivity.class);
startActivity(i);
LoggingIn.this.finish();
}
}
public void onServiceDisconnected(ComponentName className) {
// This is called when the connection with the service has been
// unexpectedly disconnected -- that is, its process crashed.
// Because it is running in our same process, we should never
// see this happen.
imService = null;
Toast.makeText(LoggingIn.this, R.string.local_service_stopped,
Toast.LENGTH_SHORT).show();
}
};
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
/*
* Start and bind the imService
*/
startService(new Intent(LoggingIn.this, MessagingService.class));
setContentView(R.layout.loggin_in);
setTitle("Login");
ImageButton loginButton = (ImageButton) findViewById(R.id.button1);
usernameText = (EditText) findViewById(R.id.username);
passwordText = (EditText) findViewById(R.id.password);
// If not logged in already
if (SaveSharedPreference.getUserName(getApplicationContext()).length() == 0) {
loginButton.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
if (imService == null) {
Toast.makeText(getApplicationContext(),
R.string.not_connected_to_service,
Toast.LENGTH_LONG).show();
// showDialog(NOT_CONNECTED_TO_SERVICE);
return;
} else if (imService.isNetworkConnected() == false) {
Toast.makeText(getApplicationContext(),
R.string.not_connected_to_network,
Toast.LENGTH_LONG).show();
// showDialog(NOT_CONNECTED_TO_NETWORK);
} else if (usernameText.length() > 0
&& passwordText.length() > 0) {
Thread loginThread = new Thread() {
private Handler handler = new Handler();
@Override
public void run() {
String result = null;
try {
result = imService.authenticateUser(
usernameText.getText().toString(),
passwordText.getText().toString());
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
if (result == null
|| result.equals(AUTHENTICATION_FAILED)) {
/*
* Authenticatin failed, inform the user
*/
handler.post(new Runnable() {
public void run() {
Toast.makeText(
getApplicationContext(),
R.string.make_sure_username_and_password_correct,
Toast.LENGTH_LONG).show();
// showDialog(MAKE_SURE_USERNAME_AND_PASSWORD_CORRECT);
}
});
} else {
/*
* if result not equal to authentication
* failed, result is equal to friend and
* group list of the user 0: is for friends,
* 1: is for groups
*/
handler.post(new Runnable() {
public void run() {
// If log in successful, then save
// username and password to shared
// preferences:
SaveSharedPreference.setUserName(
getApplicationContext(),
usernameText.getText()
.toString());
SaveSharedPreference.setPassword(
getApplicationContext(),
passwordText.getText()
.toString());
Intent i = new Intent(
LoggingIn.this,
MainActivity.class);
startActivity(i);
LoggingIn.this.finish();
}
});
}
}
};
loginThread.start();
} else {
/*
* Username or Password is not filled, alert the user
*/
Toast.makeText(getApplicationContext(),
R.string.fill_both_username_and_password,
Toast.LENGTH_LONG).show();
// showDialog(FILL_BOTH_USERNAME_AND_PASSWORD);
}
}
});
} else {
// If already logged in, pull the information and send to server to
// auto log in
Thread loginThread = new Thread() {
private Handler handler = new Handler();
@Override
public void run() {
String result = null;
try {
result = imService.authenticateUser(
SaveSharedPreference
.getUserName(getApplicationContext()),
SaveSharedPreference
.getPassword(getApplicationContext()));
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
if (result == null || result.equals(AUTHENTICATION_FAILED)) {
/*
* Authenticatin failed, inform the user
*/
handler.post(new Runnable() {
public void run() {
Toast.makeText(
getApplicationContext(),
R.string.make_sure_username_and_password_correct,
Toast.LENGTH_LONG).show();
// showDialog(MAKE_SURE_USERNAME_AND_PASSWORD_CORRECT);
}
});
} else {
/*
* if result not equal to authentication failed, result
* is equal to friend and group list of the user 0: is
* for friends, 1: is for groups
*/
handler.post(new Runnable() {
public void run() {
Intent i = new Intent(LoggingIn.this,
MainActivity.class);
startActivity(i);
LoggingIn.this.finish();
}
});
}
}
};
loginThread.start();
}
}
How can I allow the users to automatically login with my service successfully?
