I followed a youtube tutorial about connecting a MyQSL DB which runs using wamp server (on windows) to Android app. (The video link is: https://www.youtube.com/watch?v=eldh8l8yPew )
In my Android Studio code , I made a class (named "BackgroundWorker") that extends AsyncTask and should handle the communication to a PHP file that connect to the DB.
in order to open a writing channel to the DB I used BufferedWriter and OutputStream that connects to a httpURLConnection object which has the URL of my relevant php script that sits in my www folder of WAMPSERVER.
After this long itroduction , my problem is that I get IOException when trying to execute the following line:
OutputStream outputStream = httpURLConnection.getOutputStream();
I've prety much copied the whole code from the video tutorial so I doubt that there is any problem with it. I'm thinking more to the direction of the URL setting - my URL object gets the the String that have the address:
String loginURL = "http://10.0.2.2/login.php";
where "login.php" is my php script that sits in the www folder of wamp server. I understood that 10.0.0.2 is kind of a default address that represnts localhost in Android Emulators , how ever I'm using Genymotion Emulator so maybe this isn't the right address? I also tried to put all the other IP adresses that I saw when running IPCONFIG but none change the result.
I'm not so good in dubugging so I used Toasts and PublishProgress method of AsyncTask in order to find and isolate the IOException.
Here is parts of my code which I think that might be relevant to the IOException:
My BackgroundWorker class (That extends AsyncTask):
public class BackgroundWorker extends AsyncTask <String , Integer , String> {
Context context;
AlertDialog alertDialog;
public BackgroundWorker(Context userContext) {
this.context = userContext;
}
@Override
protected String doInBackground(String... params) {
// Reading the arguments in the order I sent them in MainActivity
String username = params[0];
String pass = params[1];
String type = params[2];
// Making structure for updating during the wat using Toasts (and showing the first one
int progressValue = 0; // Before if
publishProgress(progressValue);
// Initial String that will hold the text to read from server
String result = "";
// Initial the URL String , the IP address if standart for Android LocalHost
String loginURL = "http://10.0.2.2/login.php";
if (type.equals("login")) {
progressValue++; //1
publishProgress(progressValue);
try {
URL url = new URL(loginURL);
progressValue++; //2
publishProgress(progressValue);
// Building the HttpUrlConnection object
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
progressValue++; //3
publishProgress(progressValue);
// Building the writing infrastructure
// IOException occurs after the commit of the next line
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream,"UTF-8"));
progressValue++; //4
publishProgress(progressValue);
// Building the message to the PHP script
String post_data = URLEncoder.encode("user_name" , "UTF-8") + "=" + URLEncoder.encode(username , "UTF-8")
+ "&" + URLEncoder.encode("user_pass" , "UTF-8") + "=" + URLEncoder.encode(pass , "UTF-8");
progressValue++; //5
publishProgress(progressValue);
// Writing the data
bufferedWriter.write(post_data);
progressValue++; //6
publishProgress(progressValue);
// Closing all writing structures
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
// Building the Reading Infrastructure
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream , "iso-8859-1"));
// Reading the data
String line;
while ((line = bufferedReader.readLine()) != null) {
result += line;
}
// Closing all reading structures
bufferedReader.close();
inputStream.close();
httpURLConnection.disconnect();
} catch (MalformedURLException e) {
e.printStackTrace();
progressValue = 10;
publishProgress(progressValue);
} catch (IOException e) {
progressValue = 11;
publishProgress(progressValue);
e.printStackTrace();
}
}
return result;
}
@Override
protected void onProgressUpdate(Integer... values) {
int progressValue = values[0];
// Before IF statement
if (progressValue == 0) Toast.makeText(this.context , "Before if" , Toast.LENGTH_SHORT).show();
// After IF statement
if (progressValue == 1) Toast.makeText(this.context , "After if" , Toast.LENGTH_SHORT).show();
// After URL statement
if (progressValue == 2) Toast.makeText(this.context , "After URL Setting" , Toast.LENGTH_SHORT).show();
// Before Writing data
if (progressValue == 3) Toast.makeText(this.context , "After making HTML" , Toast.LENGTH_SHORT).show();
// After Writing data
if (progressValue == 4) Toast.makeText(this.context , "After making writing infra" , Toast.LENGTH_SHORT).show();
// After Writing data
if (progressValue == 5) Toast.makeText(this.context , "Before Writing data" , Toast.LENGTH_SHORT).show();
// After Writing data
if (progressValue == 6) Toast.makeText(this.context , "After Writing data" , Toast.LENGTH_SHORT).show();
// After Writing data
if (progressValue == 10) Toast.makeText(this.context , "First exception" , Toast.LENGTH_SHORT).show();
// After Writing data
if (progressValue == 11) Toast.makeText(this.context , "IO Exception" , Toast.LENGTH_SHORT).show();
}
@Override
protected void onPreExecute() {
alertDialog = new AlertDialog.Builder(context).create();
alertDialog.setTitle("Login Status");
}
@Override
protected void onPostExecute(String result) {
alertDialog.setMessage(result);
alertDialog.show();
}
}
and here is my login.php code:
<?php
require "conn.php";
$user_name = $_POST["user_name"];
$user_pass = $_POST["user_pass"];
$mysql_qry = "select * from employee_data where user like '$user_name' and password like '$user_pass';";
$result = mysqli_query($conn ,$mysql_qry);
if(mysqli_num_rows($result) > 0) {
echo "login success";
}
else {
echo "login not seccess";
}
?>
the conn.php is another scripit that just make the connection the DB. When I'm running my login.php script directly through the broswer - it works fine.
Thank you very much, I hope you can understand the problem, Noam
