For school I had to do a real simple login and authentication system on an Android app, and I'm wondering how my code can be optimised to reduce code duplication and how it can be made more object oriented?
All the app does is make an API call to my SLIM restful web service using AsyncHttpClient library and stores the AUTHkey, name, and surname of the logged in user to shared preferences.
loginScreen.java:
public class LoginScreen extends ActionBarActivity {
private String username;
private String password;
private ProgressDialog prgDialog;
private String localhostURL = "http://10.0.3.2/diploma/cloud_computing/tutorials/tutorial2/";
private String vKey;
// private String localhostURL = "http://10.0.2.2/diploma/cloud_computing/tutorials/tutorial2/";
StringEntity entity = null;
StringEntity authVkeyEntity = null;
//Will store our post data
JSONObject params = new JSONObject();
JSONObject paramsAuth = new JSONObject();
//Shared Pref vars
public static final String MyPREFERENCES = "MyPrefs";
public static final String SURNAME = "surname";
public static final String FIRSTNAME = "firstname";
public static final String VKEY = "vkey";
public static SharedPreferences sharedpreferences;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login_screen);
checkIfLoggedIn();
//Register assets
Button btnLogin = (Button) findViewById(R.id.btnLogin);
final EditText txtUsername = (EditText) findViewById(R.id.txtUsername);
final EditText txtPassword = (EditText) findViewById(R.id.txtPassword);
//Progress dialog initiation
prgDialog = new ProgressDialog(this); // Instantiate Progress Dialog object
prgDialog.setMessage("Please wait..."); // Set Progress Dialog Text
prgDialog.setCancelable(false); // Set Cancelable as False
btnLogin.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
//Get username & password
username = txtUsername.getText().toString();
password = txtPassword.getText().toString();
try {
//Append json object name and value ("username", username)
params.put("username", username);
params.put("password", password);
} catch (JSONException e) {
e.printStackTrace();
}
try {
entity = new StringEntity(params.toString());
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
entity.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
//Make the request with the above params
makeApiRequest(entity);
System.out.println("4");
}
});
}
public void makeApiRequest(StringEntity entity){
// Show Progress Dialog
prgDialog.show();
// Make RESTful webservice call using AsyncHttpClient object
AsyncHttpClient client = new AsyncHttpClient();
Context context = this.getApplicationContext();
client.post(context, localhostURL + "user", entity, "application/json", new AsyncHttpResponseHandler() {
// When the response returned by REST has Http response code '200'
@Override
public void onSuccess(String response) {
prgDialog.hide(); // Hide Progress Dialog
try {
JSONObject obj = new JSONObject(response); // Create JSON Object
//If the object has a string named "key" run the following code
if (obj.has("key")) {
Toast.makeText(getApplicationContext(), obj.getString("givename") + " You are successfully logged in!", Toast.LENGTH_LONG).show();
// Save data to shared pref and change page
saveSharedPreferences(obj.getString("surname"),obj.getString("givename"),
obj.getString("key"));
changeToWelcomeActivity();
}
else if (obj.has("pass-error"))
Toast.makeText(getApplicationContext(), "Your password is incorrect", Toast.LENGTH_LONG).show();
else if((obj.has("account-error")))
Toast.makeText(getApplicationContext(), "Your account doesn't exists", Toast.LENGTH_LONG).show();
} catch (JSONException e) {
Toast.makeText(getApplicationContext(), "Error Occured [Server's JSON response might be invalid]!", Toast.LENGTH_LONG).show();
e.printStackTrace();
}
}
// When the response returned by REST has Http response code other than '200'
@Override
public void onFailure(int statusCode, Throwable error,
String content) {
// Hide Progress Dialog
prgDialog.hide();
// When Http response code is '404'
if (statusCode == 404) {
Toast.makeText(getApplicationContext(), "Requested resource not found", Toast.LENGTH_LONG).show();
}
// When Http response code is '500'
else if (statusCode == 500) {
Toast.makeText(getApplicationContext(), "Something went wrong at server end", Toast.LENGTH_LONG).show();
}
// When Http response code other than 404, 500
else {
Toast.makeText(getApplicationContext(), "Unexpected Error occcured! [Most common Error: Device might not be connected to Internet or remote server is not up and running]", Toast.LENGTH_LONG).show();
}
}
});
}
public void saveSharedPreferences(String surname, String firstname, String key){
// Set up preferences collection
sharedpreferences = getSharedPreferences(MyPREFERENCES,
Context.MODE_PRIVATE);
//Save vkey, firstname, and vkey
SharedPreferences.Editor editor = sharedpreferences.edit();
editor.putString(SURNAME, surname );
editor.putString(FIRSTNAME, firstname );
editor.putString(VKEY, key );
editor.apply();
changeToWelcomeActivity();
}
public void checkIfLoggedIn(){
// Get vKey shared pref and assign to variable
validateSharedPreferenceAuthKeyApiRequest();
Log.d("checkIfLoggedIn", "???");
Log.d("vkey", vKey);
// If vKey is NOT empty, then don't run API request
if(vKey != "") {
validateSharedPreferenceAuthKeyApiRequest();
Log.d("in vKey = \"\"", "'VKEY is not empty'");
}
// If vKey is empty then do nothing
else
return;
}
// Get shared pref vKey and assign to vKey variable
public void getSharedPref(){
SharedPreferences prefs = this.getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE);
vKey = prefs.getString(VKEY, "");
Log.d("in SHARED PREF = \"\"", vKey);
}
// Create the JSON auth params that will be sent via the POST HTTP
public void createAuthJsonRequestParams(){
try {
//Append json object/string name and value ("auth", vKey)
paramsAuth.put("auth", vKey);
Log.d("inCreateJsonReques", vKey);
} catch (JSONException e) {
e.printStackTrace();
}
try {
authVkeyEntity = new StringEntity(paramsAuth.toString());
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
authVkeyEntity.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));
}
// Validate the auth key by sending post key of AUTH and receiving a true or false value
public void validateSharedPreferenceAuthKeyApiRequest(){
// Create the JSON object that is used below
getSharedPref();
createAuthJsonRequestParams();
// Make RESTful webservice call using AsyncHttpClient object
AsyncHttpClient client = new AsyncHttpClient();
Context context = this.getApplicationContext();
client.post(context, localhostURL + "user/auth/", authVkeyEntity, "application/json", new AsyncHttpResponseHandler() {
// When the response returned by REST has Http response code '200'
@Override
public void onSuccess(String response) {
prgDialog.hide(); // Hide Progress Dialog
try {
Log.d("in AUTHENTICATED = \"\"", "HIIHIHIHI");
JSONObject obj = new JSONObject(response); // Create JSON Object
//If the object has a string named "authenticated" run the following code
if (obj.has("authenticated")) {
Toast.makeText(getApplicationContext(), "Valid verification key!", Toast.LENGTH_LONG).show();
Log.d("in AUTHENTICATED = \"\"", vKey);
changeToWelcomeActivity();
}
// If the vKey is incorrect then post this
else if (obj.has("error_authenticated"))
Toast.makeText(getApplicationContext(), "Something has gone wrong, invalid authentication key", Toast.LENGTH_LONG).show();
} catch (JSONException e) {
Toast.makeText(getApplicationContext(), "!Error Occured [Server's JSON response might be invalid]!", Toast.LENGTH_LONG).show();
e.printStackTrace();
}
}
// When the response returned by REST has Http response code other than '200'
@Override
public void onFailure(int statusCode, Throwable error,
String content) {
// Hide Progress Dialog
prgDialog.hide();
// When Http response code is '404'
if (statusCode == 404) {
Toast.makeText(getApplicationContext(), "Requested resource not found", Toast.LENGTH_LONG).show();
}
// When Http response code is '500'
else if (statusCode == 500) {
Toast.makeText(getApplicationContext(), "Something went wrong at server end", Toast.LENGTH_LONG).show();
}
// When Http response code other than 404, 500
else {
Toast.makeText(getApplicationContext(), "Unexpected Error occcured! [Most common Error: Device might not be connected to Internet or remote server is not up and running]", Toast.LENGTH_LONG).show();
}
}
});
}
// Change from current activity to Welcome.class activity
public void changeToWelcomeActivity(){
//Change to welcome page
Intent myIntent = new Intent(this.getApplicationContext(), Welcome.class);
startActivity(myIntent);
}
Welcome.java:
public class Welcome extends ActionBarActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_welcome);
TextView txtWelcome = (TextView) findViewById(R.id.txtWelcome);
Log.d("in welcome", "eee");
if(getPreferences() == 1)
txtWelcome.setText("Welcome " + LoginScreen.sharedpreferences.getString(LoginScreen.FIRSTNAME, "") +
" " + LoginScreen.sharedpreferences.getString(LoginScreen.SURNAME, ""));
else
txtWelcome.setText("Not logged in");
}
// custom method to get preferences
public static int getPreferences(){
int returned;
if (LoginScreen.sharedpreferences.contains(LoginScreen.SURNAME))
returned = 1;
else
returned = 0;
return returned;
}
