Why doesn't the function get data from php in android?
I want to get response after post data but it fails. I want to create a login system, I have successfully submited data to php file, everything is working fine now I want to get response from same function but I'm unable to know where the issue is.
Here is the Java function:
public class PostDataGetRes extends AsyncTask<String, String, String> {
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected String doInBackground(String... strings) {
try {
postRData();
} catch (NullPointerException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(String lenghtOfFile) {
// do stuff after posting data
}
}
public void postRData() {
String result = "";
InputStream isr = null;
final String email = editEmail.getText().toString();
final String pass = editPass.getText().toString();
// Create a new HttpClient and Post Header
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://website.com/appservice.php");
try {
// Add your data
List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("id", email));
nameValuePairs.add(new BasicNameValuePair("stringdata", pass));
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(httppost);
resultView.setText("Inserted");
HttpEntity entity = response.getEntity();
isr = entity.getContent();
//convert response to string
try{
BufferedReader reader = new BufferedReader(new InputStreamReader(isr,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "n");
}
isr.close();
result=sb.toString();
}
catch(Exception e){
Log.e("log_tag", "Error converting result "+e.toString());
}
//parse json data
try {
String s = "";
JSONArray jArray = new JSONArray(result);
for(int i=0; i<jArray.length();i++){
JSONObject json = jArray.getJSONObject(i);
s = s +
"Name : "+json.getString("first_name")+"nn";
//"User ID : "+json.getInt("user_id")+"n"+
//"Name : "+json.getString("first_name")+"n"+
//"Email : "+json.getString("email")+"nn";
}
resultView.setText(s);
} catch (Exception e) {
// TODO: handle exception
Log.e("log_tag", "Error Parsing Data "+e.toString());
}
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
} catch (IOException e) {
// TODO Auto-generated catch block
}
resultView.setText("Done");
}
And here is php code:
if($id){
$query = mysql_query("SELECT first_name FROM users where email = '$id' ");
while($row=mysql_fetch_assoc($query)){
$selectedData[]=$row;
}
print(json_encode($selectedData));
}
Please help me I have tried so far but could not achieve any results. Please help me how can I get response from php file after query execution.
At first be sure you get correct JSON object from your website - try printing it as Toast.makeText() . As far the web browsers keep the html comments away, android gets it in response.
AsyncTask objects and classes aren't designed to be made the way u provided and also you can't make any UI operations in doInBackground() . AsyncTask is made in a way to not to block GUI. Here is a not much different example how it uses methods you have in AsyncTask class:
class Logging extends AsyncTask<String,String,Void>{
JSONObject json=null;
String output="";
String log=StringCheck.buildSpaces(login.getText().toString());
String pas=StringCheck.buildSpaces(password.getText().toString());
String url="http://www.mastah.esy.es/webservice/login.php?login="+log+"&pass="+pas;
protected void onPreExecute() {
Toast.makeText(getApplicationContext(), "Operation pending, please wait", Toast.LENGTH_SHORT).show();
}
@Override
protected Void doInBackground(String... params) {
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet(url);
request.addHeader("User-Agent", "User-Agent");
HttpResponse response;
try {
response = client.execute(request);
BufferedReader br = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
String line="";
StringBuilder result = new StringBuilder();
while ((line = br.readLine()) != null) {
result.append(line);
}
output=result.toString();
} catch (ClientProtocolException e) {
Toast.makeText(getApplicationContext(), "Connection problems", Toast.LENGTH_LONG).show();
} catch (IOException e) {
Toast.makeText(getApplicationContext(), "Conversion problems", Toast.LENGTH_LONG).show();
}
return null;
}
@Override
protected void onPostExecute(Void w) {
try {
json = new JSONObject(output);
if(json.getInt("err")==1){
Toast.makeText(getApplicationContext(), json.getString("msg"), Toast.LENGTH_LONG).show();
}else{
String id_user="-1";
Toast.makeText(getApplicationContext(), json.getString("msg"), Toast.LENGTH_LONG).show();
JSONArray arr = json.getJSONArray("data");
for(int i =0;i<arr.length();i++){
JSONObject o = arr.getJSONObject(i);
id_user = o.getString("id_user");
}
User.getInstance().setName(log);
User.getInstance().setId(Integer.valueOf(id_user));
Intent i = new Intent(getApplicationContext(),Discover.class);
startActivity(i);
}
} catch (JSONException e) {
}
super.onPostExecute(w);
}
}
PHP file content:
$data = array(
'err' => 0,
'msg' => "",
'data' => array(),
);
$mysqli = new MySQLi($dbhost,$dbuser,$dbpass,$dbname);
if($mysqli->connect_errno){
$data['err'] = 1;
$data['msg'] = "Brak polaczenia z baza";
exit(json_encode($data));
}
if(isset($_GET['login']) && isset($_GET['pass'])){
$mysqli->query("SET CHARACTER SET 'utf8';");
$query = $mysqli->query("SELECT banned.id_user FROM banned JOIN user ON user.id_user = banned.id_user WHERE user.login ='{$_GET['login']}' LIMIT 1;");
if($query->num_rows){
$data['err']=1;
$data['msg']="User banned";
exit(json_encode($data));
}else{
$query = $mysqli->query("SELECT login FROM user WHERE login='{$_GET['login']}' LIMIT 1;");
if($query->num_rows){
$query = $mysqli->query("SELECT pass FROM user WHERE pass ='{$_GET['pass']}' LIMIT 1;");
if($query->num_rows){
$data['msg']="Logged IN!";
$query = $mysqli->query("SELECT id_user FROM user WHERE login='{$_GET['login']}' LIMIT 1;");
$data['data'][]=$query->fetch_assoc();
exit(json_encode($data));
}else{
$data['err']=1;
$data['msg']="Wrong login credentials.";
exit(json_encode($data));
}
}else{
$data['err']=1;
$data['msg']="This login doesn't exist.";
exit(json_encode($data));
}
}
}else{
$data['err']=1;
$data['msg']="Wrong login credentials";
exit(json_encode($data));
}
I have created there small dictionary $data for my app. I used its err key as a flag to know if any error appeared, msg to inform user about operation results and data to send JSON objects.
Thing you would want to do with if(response == true) if it had exist is similar to construction i used in my onPostExecute(Void w) method in AsyncTask :
if(json.getInt("err")==1){
//something went wrong
}else{
//everything is okay, get JSON, inform user, start new Activity
}
Also here is the way I used $data['data'] to get JSON response:
if($query->num_rows){
while($res=$query->fetch_assoc()){
$data['data'][]=$res;
}
exit(json_encode($data));
}
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