First of all i am newbie in android. I have read almost every similar topic but i couldn't find specific answers. The problem is at json parsing of my Login activity. What can i do to find where NullPointException come from; Im stucked for over one week... Thanks in advance
I have to mention that my app worked like a charm. The problems began after trying to connect to my localhost fare away from my wifi. Isnt that very strange;
Login.java
package com.example.tranfer;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;
public class Login extends Activity implements OnClickListener{
private EditText user, pass;
private Button mSubmit, mRegister;
// Progress Dialog
private ProgressDialog pDialog;
// JSON parser class
JSONParser jsonParser = new JSONParser();
//php login script location:
//localhost :
//testing on your device
//put your local ip instead, on windows, run CMD > ipconfig
//or in mac's terminal type ifconfig and look for the ip under en0 or en1
// private static final String LOGIN_URL = "http://192.168.1.4:80/etruck1/login1.php";
//testing on Emulator:
private static final String LOGIN_URL = "http://.............................";
//testing from a real server:
//private static final String LOGIN_URL = "http://www.yourdomain.com/webservice/login.php";
//JSON element ids from repsonse of php script:
private static final String TAG_SUCCESS = "success";
private static final String TAG_MESSAGE = "message";
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
//setup input fields
user = (EditText)findViewById(R.id.edtusername);
pass = (EditText)findViewById(R.id.edtpassword);
//setup buttons
mSubmit = (Button)findViewById(R.id.signin);
mRegister = (Button)findViewById(R.id.register);
//register listeners
mSubmit.setOnClickListener(this);
mRegister.setOnClickListener(this);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.signin:
new AttemptLogin().execute();
break;
case R.id.register:
Intent i = new Intent(this, RegistrationForm.class);
startActivity(i);
break;
default:
break;
}
}
class AttemptLogin extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
boolean failure = false;
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(Login.this);
pDialog.setMessage("Attempting login...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
@Override
protected String doInBackground(String... args) {
// TODO Auto-generated method stub
// Check for success tag
int success;
String username = user.getText().toString();
String password = pass.getText().toString();
Log.d(username, username);
try {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("username", username));
params.add(new BasicNameValuePair("password", password));
Log.d("request!", "starting");
// getting product details by making HTTP request
JSONObject json = jsonParser.makeHttpRequest(
LOGIN_URL, "POST", params);
// check your log for json response
Log.d("Login attempt", json.toString());
// json success tag
success = json.getInt(TAG_SUCCESS);
if (success == 1) {
Log.d("Login Successful!", json.toString());
Intent i = new Intent(Login.this, MainActivity1.class);
finish();
startActivity(i);
return json.getString(TAG_MESSAGE);
}else{
Log.d("Login Failure!", json.getString(TAG_MESSAGE));
return json.getString(TAG_MESSAGE);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog once product deleted
pDialog.dismiss();
if (file_url != null){
Toast.makeText(Login.this, file_url, Toast.LENGTH_LONG).show();
}
}
}
@Override
// Το παρακάτω το πρόσθεσα εγω
protected void onDestroy() {
if (pDialog != null) {
if (pDialog.isShowing()) {
pDialog.dismiss();
pDialog = null;
}
}
super.onDestroy();
}
}
Login.php
?php
//load and connect to MySQL database stuff
require("config.inc.php");
$query_params=null;
if (!empty($_POST)) {
//gets user's info based off of a username.
$query = "
SELECT
id,
username,
password
FROM registration
WHERE
username = :username ";
$query_params = array(
':username' => $_POST['username']
);
try {
$stmt = $db->prepare($query);
$result = $stmt->execute();
$stmt->execute($query_params);
}
catch (PDOException $ex) {
// For testing, you could use a die and message.
//die("Failed to run query: " . $ex->getMessage());
//or just use this use this one to product JSON data:
$response["success"] = 0;
$response["message"] = "Database Error1. Please Try Again!";
die(json_encode($response));
}
//we initialize it as false.
$validated_info = false;
//fetching all the rows from the query
$row = $stmt->fetch();
$login_ok = false;
if ($row) {
//if we encrypted the password, we would unencrypt it here, but in our case we just
//compare the two passwords
if ($_POST['password'] === $row['password']) {
$login_ok = true;
}
}
// If the user logged in successfully, then we send them to the private members-only page
// Otherwise, we display a login failed message and show the login form again
if ($login_ok) {
$response["success"] = 1;
$response["message"] = "Συνδεθήκατε επιτυχώς!";
die(json_encode($response));
} else {
$response["success"] = 0;
$response["message"] = "Λανθασμένα στοιχεία!";
die(json_encode($response));
}
} else {
?>
<h1>Login</h1>
<form action="login.php" method="post">
Username:<br />
<input type="text" name="username" placeholder="username" />
<br /><br />
Password:<br />
<input type="password" name="password" placeholder="password" value="" />
<br /><br />
<input type="submit" value="Login" />
</form>
<a href="register.php">Register</a>
<?php
}
?>
and Log.cat
06-07 14:24:08.245: E/JSON Parser(28772): Error parsing data org.json.JSONException: Value Failed of type java.lang.String cannot be converted to JSONObject
06-07 14:24:08.315: W/dalvikvm(28772): threadid=12: thread exiting with uncaught exception (group=0x411342a0)
06-07 14:24:09.036: E/AndroidRuntime(28772): FATAL EXCEPTION: AsyncTask #1
06-07 14:24:09.036: E/AndroidRuntime(28772): java.lang.RuntimeException: An error occured while executing doInBackground()
06-07 14:24:09.036: E/AndroidRuntime(28772): at android.os.AsyncTask$3.done(AsyncTask.java:299)
06-07 14:24:09.036: E/AndroidRuntime(28772): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
06-07 14:24:09.036: E/AndroidRuntime(28772): at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
06-07 14:24:09.036: E/AndroidRuntime(28772): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
06-07 14:24:09.036: E/AndroidRuntime(28772): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
06-07 14:24:09.036: E/AndroidRuntime(28772): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:230)
06-07 14:24:09.036: E/AndroidRuntime(28772): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
06-07 14:24:09.036: E/AndroidRuntime(28772): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
06-07 14:24:09.036: E/AndroidRuntime(28772): at java.lang.Thread.run(Thread.java:856)
06-07 14:24:09.036: E/AndroidRuntime(28772): Caused by: java.lang.NullPointerException
06-07 14:24:09.036: E/AndroidRuntime(28772): at com.example.tranfer.Login$AttemptLogin.doInBackground(Login.java:127)
06-07 14:24:09.036: E/AndroidRuntime(28772): at com.example.tranfer.Login$AttemptLogin.doInBackground(Login.java:1)
06-07 14:24:09.036: E/AndroidRuntime(28772): at android.os.AsyncTask$2.call(AsyncTask.java:287)
06-07 14:24:09.036: E/AndroidRuntime(28772): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
06-07 14:24:09.036: E/AndroidRuntime(28772): ... 5 more
