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Display a toast in Async

So I am trying to display a toast if the link that provided in "EditText" is equal to a specific link.
Else the code keep runing until result.
Thats how I tried to do(Its not detecting the link):
if (urls[0].equals ("http://api.openweathermap.org/data/2.5/weather?q=null&appid=8e19904c6a1db15924eef5084a978de7"))
{
Log.e("Test","Error!");
}
My main code,if you need anything else from the code just tell me and I will upload:
public class DownloadTask extends AsyncTask<String,Void,String>{
#Override
protected String doInBackground(final String... urls) {
Log.e("URL", "Loading url = " + urls[0]);
StringBuilder result = new StringBuilder();
if (urls[0].equals ("http://api.openweathermap.org/data/2.5/weather?q=null&appid=8e19904c6a1db15924eef5084a978de7"))
{
Log.e("Test","DSADSADASDASDAS");
}
URL url;
HttpURLConnection urlConnection = null;
try{
url = new URL(urls[0]);
urlConnection = (HttpURLConnection) url.openConnection();
InputStream in = urlConnection.getInputStream();
InputStreamReader reader = new InputStreamReader(in);
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(in));
String line;
while ((line = bufferedReader.readLine()) != null) {
result.append(line).append("\n");
}
return result.toString();
} catch (MalformedURLException e) {
result.append("Error: MalformedURLException");
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return result.toString();
}
#SuppressLint("SetTextI18n")
#Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
try {
JSONObject jsonObject = new JSONObject(s);
String weatherInfo = jsonObject.getString("weather");
Log.e("JSON data",""+weatherInfo);
Toast.makeText(MainActivity.this, mCityName +" has been loaded", Toast.LENGTH_SHORT).show();
JSONArray jArray = new JSONArray(weatherInfo);
for(int i = 0; 0 < jArray.length(); i++){
JSONObject partJson = jArray.getJSONObject(i);
mMain.setText("The Weather in " + mCityName + " is: " + partJson.getString("main"));
mDescription.setText("And " + partJson.getString("description"));
mMain.setVisibility(View.VISIBLE);
mDescription.setVisibility(View.VISIBLE);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
Thank you !

To show a Toast from a background thread you need to call it inside runOnUIThread like this:
runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(this, "URL is the same", Toast.LENGTH_SHORT).show();
}
});
This is assuming your AsincTask is inside an activity class.
runOnUIThread is a method of Activity class, and you need a Context to show the Toast.
If your AsyncTask is in a separate class, you will need to provide an Activity as a parameter, or use an Intent to communicate with an Activity.

How to get the JSON error response and toast it?

Here's my code for when i trying to register user and need a toast which is response from server regarding user already exist. i can post successfully to server using json but if there's response i have to idea how to catch it the image shows example when using postman.
public class RegisterActivity extends AppCompatActivity implements View.OnClickListener{
private EditText signupInputName, signupInputEmail, signupInputPassword, retypeInputPassword;
private Button btnSignUp;
private Button btnLinkLogin;
private String message = "";
private int code = 0;
Person person;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
signupInputName = (EditText) findViewById(R.id.signup_input_name);
signupInputEmail = (EditText) findViewById(R.id.signup_input_email);
signupInputPassword = (EditText) findViewById(R.id.signup_input_password);
retypeInputPassword = (EditText) findViewById(R.id.signup_retype_password);
btnSignUp = (Button) findViewById(R.id.btn_signup);
btnLinkLogin = (Button) findViewById(R.id.btn_link_login);
btnSignUp.setOnClickListener(this);
btnLinkLogin.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent i = new Intent(getApplicationContext(),LoginActivity.class);
startActivity(i);
}
});
}
public String POST(String url, Person person)
{
InputStream inputStream = null;
String result = "";
try {
// 1. create HttpClient
HttpClient httpclient = new DefaultHttpClient();
// 2. make POST request to the given URL
HttpPost httppost = new HttpPost(url);
String json = "";
// 3. build jsonObject
JSONObject jsonObject = new JSONObject();
jsonObject.accumulate("user_name", person.getUsername());
jsonObject.accumulate("email", person.getEmail());
jsonObject.accumulate("password", person.getPassword());
// 4. convert JSONObject to JSON to String
json = jsonObject.toString();
// ** Alternative way to convert Person object to JSON string usin Jackson Lib
// ObjectMapper mapper = new ObjectMapper();
// json = mapper.writeValueAsString(person);
// 5. set json to StringEntity
StringEntity se = new StringEntity(json);
// 6. set httpPost Entity
httppost.setEntity(se);
// 7. Set some headers to inform server about the type of the content
httppost.setHeader("Accept", "application/json");
httppost.setHeader("Content-type", "application/json");
// 8. Execute POST request to the given URL
HttpResponse httpResponse = httpclient.execute(httppost);
// 9. receive response as inputStream
inputStream = httpResponse.getEntity().getContent();
// 10. convert inputstream to string
if(inputStream != null)
result = convertInputStreamToString(inputStream);
else
result = "Error! email exist";
} catch (Exception e) {
Log.d("InputStream", e.getLocalizedMessage());
}
// 11. return result
return result;
}
#Override
public void onClick(View view) {
if(validate() == 1)
{
Toast.makeText(getBaseContext(), message.toString(), Toast.LENGTH_SHORT).show();
}
else if (validate() == 2)
{
Toast.makeText(getBaseContext(), message.toString(), Toast.LENGTH_SHORT).show();
}
else if (validate() == 3)
{
Toast.makeText(getBaseContext(), message.toString(), Toast.LENGTH_SHORT).show();
}
else if (validate() == 4)
{
//Toast.makeText(getBaseContext(), "Success", Toast.LENGTH_SHORT).show();
new HttpAsyncTask().execute("http://ip-addressses/api/register");
}
}
private class HttpAsyncTask extends AsyncTask<String, Void, String>
{
#Override
protected String doInBackground(String... urls) {
person = new Person();
person.setUsername(signupInputName.getText().toString());
person.setEmail(signupInputEmail.getText().toString());
person.setPassword(signupInputPassword.getText().toString());
return POST(urls[0],person);
}
// onPostExecute displays the results of the AsyncTask.
#Override
protected void onPostExecute(String result) {
JSONObject jObject;
try {
jObject = new JSONObject(result);
if (jObject.has("error")) {
String aJsonString = jObject.getString("error");
Toast.makeText(getBaseContext(), aJsonString, Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(getBaseContext(), "Login Successful", Toast.LENGTH_SHORT).show();
}
} catch (JSONException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
}
private int validate() {
if(signupInputName.getText().toString().trim().equals("") || signupInputEmail.getText().toString().trim().equals("") || signupInputPassword.getText().toString().trim().equals("") || retypeInputPassword.getText().toString().trim().equals(""))
{
code = 1;
message = "Complete the form!";
}
else if (!(signupInputPassword.getText().toString().equals(retypeInputPassword.getText().toString())))
{
code = 2;
message = "Re-check password";
}
else if (!isValidEmail(signupInputEmail.getText().toString()) ) {
code = 3;
message = "Invalid email";
}
else
code = 4;
return code;
}
public final static boolean isValidEmail(String target)
{
if (target == null) {
return false;
} else {
Matcher match = Patterns.EMAIL_ADDRESS.matcher(target);
return match.matches();
}
}
private static String convertInputStreamToString(InputStream inputStream) throws IOException{
BufferedReader bufferedReader = new BufferedReader( new InputStreamReader(inputStream));
String line = "";
String result = "";
while((line = bufferedReader.readLine()) != null)
result += line;
inputStream.close();
return result;
}
}
Postman response when email exist

Just change this code:
jObject = new JSONObject(result);
if (jObject.has("error"))
{
String aJsonString = jObject.getString("error");
Toast.makeText(getBaseContext(), aJsonString, Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(getBaseContext(), "Login Successful", Toast.LENGTH_SHORT).show();
}
}
catch (JSONException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
Toast.makeText(getBaseContext(),result+"" , Toast.LENGTH_SHORT).show();
}
So by this code, if your response is not JSON it will throw exception in catch. And here you can show toast.

Compiler skips try bracket?

So I have this little App that should only show a JSON-Object(not even parse it) in the Textview "tvJsonItem" after you push the button "btnHit". I have built in multiple Toasts to follow its procedure, but if i push the button, i only get the Toast Test1 from the onPostExecute. It seems like the Programme skips the whole try bracket.
public class MainActivity extends AppCompatActivity {
private TextView tvData;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btnHit = (Button) findViewById(R.id.btnHit);
tvData = (TextView) findViewById(R.id.tvJsonItem);
}
public void onClick(View view) {
new JSONTask().execute();
Toast.makeText(getApplicationContext(), "onClick", Toast.LENGTH_LONG);
}
public class JSONTask extends AsyncTask<String, String, String> {
#Override
protected String doInBackground(String...params) {
HttpURLConnection connection = null;
BufferedReader reader = null;
URL url = null;
try {
url = new URL("https://jsonparsingdemo-cec5b.firebaseapp.com/jsonData/moviesDemoItem.txt");
connection = (HttpURLConnection) url.openConnection();
connection.connect();
InputStream stream = connection.getInputStream();
reader = new BufferedReader(new InputStreamReader(stream));
Toast.makeText(MainActivity.this, "test2", Toast.LENGTH_LONG).show();
StringBuffer buffer = new StringBuffer();
String line = "";
while ((line = reader.readLine()) != null) {
buffer.append(line);
}
String result = buffer.toString();
return result;
} catch (MalformedURLException e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), "Malformed", Toast.LENGTH_LONG);
} catch (IOException e) {
e.printStackTrace();
Toast.makeText(getApplicationContext(), "IOException", Toast.LENGTH_LONG);
} finally {
if (connection != null) {
connection.disconnect();
}
if (reader != null) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
}
protected void onPostExecute(String result){
super.onPostExecute(result);
tvData.setText(result);
Toast.makeText(getApplicationContext(), "test1", Toast.LENGTH_LONG).show();
}
}
}

You can't call toast.show() in doInBackground, because toast.show() should call in Main UI Thread.
for the test, convert toast.show() to log.d()...

Android 23 (Marshmallow) and Higher permission Having a heck of a time

First, Thank you very much for looking at this!
I've been handed an app someone wrote before Marshmallow. I've fixed the Theme and SSL issues that came with Nougat but I'm having a heck of a time with Write to External Storage Permission or something associated. Debug is lacking or I'm not using it properly. This app creates a file onto the device and adds the ssl cert and login info in a folder called My Documents.
When I open the app it say network timeout right away. That message is from LoginActivity.java . I click ok then I get the Android pop up asking to allow permissions. I allow it. After that I put in the username and password and click login. It instantly gives the network timeout message from LoginActivity.java. LoginActivity.java is the Main Activity. If I click ok it's back to the login screen. All permissions are in the Android Manifest as well.
Maybe it's not from permissions but it works fine in version 22. I've worked on this 12 hours today and thought if you guys could help that'd be great. I'm a network engineer dabbling in Java so please excuse my question if it's "ugly".
I tried to find a line by line debug like I've done with phonegap but wasn't successful.
My Apps Main Activity LoginActivity.java and associated activity is LoginScreen.java and shown below.
LoginActivity.java
public class LoginActivity extends Activity {
private String userName = "";
private static final int PERMS_REQUEST_CODE = 123;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.blackactivity);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
new SSLHandler().execute();
if(Variables.testing)
{
}
if (hasPermissions()){
// our app has permissions.
try {
attemptLogin();
} catch (Exception e) {
GUI.oneOptionDialog(this, e.toString(), "OK", false);
e.printStackTrace();
}
}
else {
//our app doesn't have permissions, So i m requesting permissions.
requestPerms();
}
}
//Begin Permission Methods
#SuppressLint("WrongConstant")
private boolean hasPermissions(){
int res = 0;
//string array of permissions,
String[] permissions = new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE};
for (String perms : permissions){
res = checkCallingOrSelfPermission(perms);
if (!(res == PackageManager.PERMISSION_GRANTED)){
return false;
}
}
return true;
}
private void requestPerms(){
String[] permissions = new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE};
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
requestPermissions(permissions,PERMS_REQUEST_CODE);
}
}
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[] grantResults) {
boolean allowed = true;
switch (requestCode){
case PERMS_REQUEST_CODE:
for (int res : grantResults){
// if user granted all permissions.
allowed = allowed && (res == PackageManager.PERMISSION_GRANTED);
}
break;
default:
// if user not granted permissions.
allowed = false;
break;
}
if (allowed){
//user granted all permissions we can perform our task.
try {
attemptLogin();
} catch (Exception e) {
GUI.oneOptionDialog(this, e.toString(), "OK", false);
e.printStackTrace();
}
}
else {
// we will give warning to user that they haven't granted permissions.
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (shouldShowRequestPermissionRationale(Manifest.permission.WRITE_EXTERNAL_STORAGE)){
Toast.makeText(this, "Storage Permissions denied.", Toast.LENGTH_SHORT).show();
}
}
}
}
//End Permission Methods
private void attemptLogin() throws IOException {
String filepath = Variables.fileFolder + "/login.txt";
File tempFile = new File(filepath);
if (!tempFile.exists()) {
startActivity(new Intent(LoginActivity.this, LoginScreen.class));
finish();
}
String username = "";
String passwordHash = "";
String salt = "";
boolean fileExists = false;
BufferedReader reader = null;
FileInputStream fileInputStream = null;
try {
fileInputStream = new FileInputStream(new File(filepath));
InputStreamReader inputStreamReader = new InputStreamReader(
fileInputStream);
reader = new BufferedReader(inputStreamReader);
username = reader.readLine();
passwordHash = reader.readLine();
salt = reader.readLine();
reader.close();
userName = username;
fileInputStream.close();
} catch (Exception e) {
startActivity(new Intent(LoginActivity.this, LoginScreen.class));
finish();
}
fileExists = true;
if (fileExists) {
try {
LoginTask login = new LoginTask();
login.execute(username, passwordHash, salt);
} catch (Exception e) {
}
}
}
private class LoginTask extends AsyncTask<String, Void, Boolean> {
Boolean success = false;
Boolean timedOut = false;
ProgressDialog mProgressDialog;
#Override
protected void onPostExecute(Boolean result) {
try {
mProgressDialog.dismiss();
} catch (Exception e) {
}
if (timedOut) {
AlertDialog.Builder builder = new AlertDialog.Builder(
LoginActivity.this);
builder.setMessage("Network Timed Out").setTitle("Notice");
builder.setPositiveButton("OK",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.dismiss();
startActivity(new Intent(LoginActivity.this,
LoginScreen.class));
finish();
}
});
AlertDialog dialog = builder.create();
dialog.show();
} else {
if (result) {
Variables.storeTechName(userName, LoginActivity.this);
Variables.assignTechName();
startActivity(new Intent(LoginActivity.this,
MainActivity.class));
finish();
} else {
startActivity(new Intent(LoginActivity.this,
LoginScreen.class));
finish();
}
}
}
#Override
protected void onPreExecute() {
mProgressDialog = ProgressDialog.show(LoginActivity.this,
"Loading...", "Logging you in...");
mProgressDialog.getWindow().setGravity(Gravity.BOTTOM);
}
#Override
protected Boolean doInBackground(String... params) {
try {
URL json = new URL(Variables.urlPrefix + "/Login.svc/input?a="
+ params[0] + "&b=" + params[1] + "&c=" + params[2]);
HttpsURLConnection jc = (HttpsURLConnection) json
.openConnection();
jc.setConnectTimeout(Variables.timeoutTimeLimit);
jc.setSSLSocketFactory(Variables.context.getSocketFactory());
InputStreamReader input = new InputStreamReader(
jc.getInputStream());
BufferedReader reader = new BufferedReader(input);
String line = reader.readLine();
JSONObject jsonResponse = new JSONObject(line);
success = jsonResponse.getBoolean("LoginMethodResult");
jc.disconnect();
reader.close();
} catch (Exception e) {
System.out.println(e.toString());
timedOut = true;
}
return success;
}
}
#Override
protected void onPause() {
super.onPause();
}
}
LoginScreen.java
public class LoginScreen extends Activity {
private String userName;
private static final int PERMS_REQUEST_CODE = 123;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.loginscreen);
getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
if (!SSLHandler.loaded) {
new SSLHandler().execute();
}
// Creates login and name files and attempts to log in
Button createButton = (Button) findViewById(R.id.createbutton);
createButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
if (((EditText) findViewById(R.id.usernamefield)).getText()
.toString().isEmpty()
|| ((EditText) findViewById(R.id.passwordfield))
.getText().toString().isEmpty()) {
GUI.oneOptionDialog(LoginScreen.this,
"Missing field entries", "OK", false);
} else {
createLoginFile();
((EditText) findViewById(R.id.usernamefield)).setText("");
((EditText) findViewById(R.id.passwordfield)).setText("");
attemptLogin();
}
}
});
}
#SuppressLint("WrongConstant")
private boolean hasPermissions(){
int res = 0;
//string array of permissions,
String[] permissions = new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE};
for (String perms : permissions){
res = checkCallingOrSelfPermission(perms);
if (!(res == PackageManager.PERMISSION_GRANTED)){
return false;
}
}
return true;
}
private void requestPerms(){
String[] permissions = new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE};
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
requestPermissions(permissions,PERMS_REQUEST_CODE);
}
}
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[] grantResults) {
boolean allowed = true;
switch (requestCode){
case PERMS_REQUEST_CODE:
for (int res : grantResults){
// if user granted all permissions.
allowed = allowed && (res == PackageManager.PERMISSION_GRANTED);
}
break;
default:
// if user not granted permissions.
allowed = false;
break;
}
if (allowed){
//user granted all permissions we can perform our task.
createFiles();
}
else {
// we will give warning to user that they haven't granted permissions.
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (shouldShowRequestPermissionRationale(Manifest.permission.WRITE_EXTERNAL_STORAGE)){
Toast.makeText(this, "Storage Permissions denied.", Toast.LENGTH_SHORT).show();
}
}
}
}
private void createFiles() {
}
private void attemptLogin() {
String username = "";
String passwordHash = "";
String salt = "";
boolean fileExists = false;
try {
String filepath = Variables.fileFolder + "/login.txt";
FileInputStream fileInputStream = new FileInputStream(new File(
filepath));
InputStreamReader inputStreamReader = new InputStreamReader(
fileInputStream);
BufferedReader reader = new BufferedReader(inputStreamReader);
username = reader.readLine();
passwordHash = reader.readLine();
salt = reader.readLine();
reader.close();
userName = username;
fileInputStream.close();
fileExists = true;
}
catch (Exception e) {
GUI.oneOptionDialog(LoginScreen.this,
"Login file does not exist. Please enter login info.",
"OK", false);
}
if (fileExists) {
try {
LoginTask login = new LoginTask();
login.execute(username, passwordHash, salt);
} catch (Exception e) {
}
}
}
private class LoginTask extends AsyncTask<String, Void, Boolean> {
Boolean timedOut = false;
Boolean success = false;
ProgressDialog mProgressDialog;
#Override
protected void onPostExecute(Boolean result) {
try {
mProgressDialog.dismiss();
} catch (Exception e) {
}
if (timedOut) {
GUI.oneOptionDialog(LoginScreen.this, "Network Timed Out",
"OK", false);
} else {
if (result) {
Variables.storeTechName(userName, LoginScreen.this);
Variables.assignTechName();
startActivity(new Intent(LoginScreen.this,
MainActivity.class));
finish();
} else {
GUI.oneOptionDialog(LoginScreen.this,
"Login Failed. Please try again.", "OK", false);
}
}
}
#Override
protected void onPreExecute() {
mProgressDialog = ProgressDialog.show(LoginScreen.this,
"Loading...", "Logging you in...");
}
#Override
protected Boolean doInBackground(String... params) {
try {
URL json = new URL(Variables.urlPrefix + "/Login.svc/input?a="
+ params[0] + "&b=" + params[1] + "&c=" + params[2]);
HttpsURLConnection jc = (HttpsURLConnection) json
.openConnection();
jc.setConnectTimeout(Variables.timeoutTimeLimit);
jc.setSSLSocketFactory(Variables.context.getSocketFactory());
jc.setConnectTimeout(Variables.timeoutTimeLimit);
InputStreamReader input = new InputStreamReader(
jc.getInputStream());
BufferedReader reader = new BufferedReader(input);
String line = reader.readLine();
JSONObject jsonResponse = new JSONObject(line);
success = jsonResponse.getBoolean("LoginMethodResult");
jc.disconnect();
reader.close();
} catch (Exception e) {
timedOut = true;
}
return success;
}
}
private void createLoginFile() {
try {
File dir = new File(Variables.fileFolder);
if (!dir.isDirectory()) {
dir.mkdirs();
}
String filepath = Variables.fileFolder + "/Login.txt";
String username = ((EditText) findViewById(R.id.usernamefield))
.getText().toString();
String password = ((EditText) findViewById(R.id.passwordfield))
.getText().toString();
String salt = new RandomString(20).nextString();
String passwordHash = Variables.sha256(password + salt);
PrintWriter writer = new PrintWriter(filepath, "UTF-8");
writer.println(username);
writer.println(passwordHash);
writer.println(salt);
writer.close();
} catch (Exception e) {
GUI.oneOptionDialog(LoginScreen.this, e.toString(), "OK", false);
}
}
#Override
protected void onPause() {
super.onPause();
}
}

How to prevent duplicate entry in registration activity with "Username already taken"

I would like to include a code such that, when a user registers a username that has already been used in my app, he/she will get a toast saying "Username is already taken".
Register.java
public class Register extends AppCompatActivity {
EditText regEmail, regPassword;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_register);
regEmail = (EditText)findViewById(R.id.reg_email);
regPassword = (EditText)findViewById(R.id.reg_password);
}
public void OnReg(View view) {
String strEmail = regEmail.getText().toString();
String strPassword = regPassword.getText().toString();
String type = "register";
BackgroundWorker backgroundWorker = new BackgroundWorker(this);
backgroundWorker.execute(type, strEmail, strPassword);
}}
BackgroundWorker.java
public class BackgroundWorker extends AsyncTask<String,Void,String> {
Context context;
AlertDialog alertDialog;
BackgroundWorker (Context ctx){
context = ctx;
}
#Override
protected String doInBackground(String... params) {
String type = params[0];
String login_url = "http://10.93.22.231/login.php";
String register_url = "http://10.93.22.231/register.php";
if (type.equals("login")){
try {
String email = params[1];
String password = params[2];
URL url = new URL(login_url);
HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
String post_data = URLEncoder.encode("email","UTF-8")+"="+URLEncoder.encode(email,"UTF-8")+"&"
+URLEncoder.encode("password","UTF-8")+"="+URLEncoder.encode(password,"UTF-8");
bufferedWriter.write(post_data);
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, "iso-8859-1"));
String result = "";
String line = "";
while ((line = bufferedReader.readLine()) != null) {
result += line;
}
bufferedReader.close();
inputStream.close();
httpURLConnection.disconnect();
return result;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
} else if (type.equals("register")){
try {
String regEmail = params[1];
String regPassword = params[2];
URL url = new URL(register_url);
HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
String post_data = URLEncoder.encode("email","UTF-8")+"="+URLEncoder.encode(regEmail,"UTF-8")+"&"
+URLEncoder.encode("password","UTF-8")+"="+URLEncoder.encode(regPassword,"UTF-8");
bufferedWriter.write(post_data);
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream, "iso-8859-1"));
String result = "";
String line = "";
while ((line = bufferedReader.readLine()) != null) {
result += line;
}
bufferedReader.close();
inputStream.close();
httpURLConnection.disconnect();
return result;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
return null;
}
#Override
protected void onPreExecute() {
alertDialog = new AlertDialog.Builder(context).create();
alertDialog.setTitle("Login Status");
}
#Override
protected void onPostExecute(String result) {
alertDialog.setMessage(result);
if (result.contains("success")) {
Intent intent = new Intent(context, MainActivity.class);
context.startActivity(intent);
} else {
alertDialog.show();
}
}
#Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
}
Register.php
<?php
require "conn.php";
$email = $_POST["email"];
$password = $_POST["password"];
$mysql_qry = "INSERT INTO users (email, password) VALUES ('$email','$password')";
if($conn->query($mysql_qry) === TRUE){
echo "Insert successful";
} else {
echo "Insert failed, please try again.";
}
$conn->close();
?>

Toast.makeText(YourActivtyOrContext,"Username Taken", Toast.LENGTH_LONG).show();

on Post execute you can do some thing like this
also at the server level if the username already exists you should not save the record instead of that you should pass the value that username already exists
#Override
protected void onPostExecute(String result) {
if (result.contains("success")) {
Intent intent = new Intent(context, MainActivity.class);
context.startActivity(intent);
} else {
Toast.makeText(context,result, Toast.LENGTH_LONG).show();
}
}

Hey please check this code, maybe it can solve your problem. This is simple code.
if (ConnectivityDetector.isConnectingToInternet(RegisterActivity.this)) {
JSONObject jsonObjectInput = new JSONObject();
jsonObjectInput.put(WebField.REGISTER_USER.REQUEST_USER_NAME,
edtUserName.getText().toString());
String mode = "RegisterUser";
new GetJsonWithCallBack(RegisterActivity.this, jsonObjectInput,
1, mode, new OnUpdateListener() {
#Override
public void onUpdateComplete(JSONObject jsonObject,
boolean isSuccess) {
if (isSuccess) {
try {
if (jsonObject != null) {
if (jsonObject.has("userDetail")) {
JSONObject jsonUserDetails = jsonObject.getJSONObject("userDetail");
RegisterData regData = new RegisterData();
regData.setUserName(jsonUserDetails.getString(WebField.REGISTER_USER.RESPONSE_USER_NAME));
SessionManager.saveData(RegisterActivity.this, regData);
finish();
}
}
} catch (Exception e) {
e.printStackTrace();
}
} else {
if (jsonObject != null) {
try {
String Status = jsonObject.getString("status");
String message = jsonObject.getString("message");
if (message.equalsIgnoreCase("User already Exists")) {
GlobalMethod.showAlert(RegisterActivity.this, "User name already exists..!!");
} else if (message.equalsIgnoreCase("Email id already Exists")) {
GlobalMethod.showAlert(RegisterActivity.this, "Email id already exists..!!");
} else if (message.equalsIgnoreCase("Mobile no already Exists")) {
GlobalMethod.showAlert(RegisterActivity.this, "Mobile no already exists..!!");
} else {
GlobalMethod.showAlert(RegisterActivity.this, jsonObject.getString("message"));
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
}
}
}
}).execute();
} else {
AlertDialogUtility.showInternetAlert(RegisterActivity.this);
}
} catch (Exception e) {
e.printStackTrace();
}

try this way
#Override
protected void onPostExecute(String result) {
alertDialog.setMessage(result);
if (result.contains("success")) {
JSONObject json= new JSONObject(result);
if(json.has("message"){
String message=json.getString("message");
Toast.makeText(ctx,message,Toast.LENGTH_SHORT).show();
}
Intent intent = new Intent(context, MainActivity.class);
context.startActivity(intent);
} else {
alertDialog.show();
}
}
UPDATE
User validation query
$mysql_qry="SELECT * FROM users WHERE email='$email'";
if($conn->query($mysql_qry) === TRUE){
}else{}