Posting JSON from PHP to Android issue

Question

Hello i am currently having an issue sending a JSON object from my PHP to an Android device. I have done this before with another person and it worked fine but now it does not seem to work.

It is a simple login script. It should return the user's data or "false" based on whether the login email and password entered are correct.

The response is visible when tried in a browser but according to my colleague, he gets an empty array when viewing on his android development machine.

This is the php code:

<?php
 include('config.php');
 include('functions.php');
 include('password_hash_lib/password.php');
 if (!isset($_REQUEST["device"]))
 {
 $Email = $_POST['Email'];
 $Password = $_POST['Password'];
 try
 {
 if (authenticate($Email, $Password))
 {
 echo "true";
 }
 else {
 echo "false";
 }
 }
 catch (Exception $e)
 {
 echo $e->getMessage();
 }
 }
 else if (isset($_REQUEST["device"]))
 {
 $device = $_REQUEST['device'];
 $Email = $_REQUEST['email'];
 $Password = $_REQUEST['password'];
 if ($device == 'mobi')
 { 
 try
 {
 if (authenticate($Email, $Password))
 {
 $curruser = explode("+", $_SESSION['sess_user_auth']);
 $arr = new ArrayObject(Array(), ArrayObject::STD_PROP_LIST); 
 $arr->userid = $curruser[0];
 $arr->email = $curruser[1];
 $arr->fullname = $curruser[2];
 $arr->displaypic = $curruser[3];
 $arr->displayname = $curruser[4];
 echo str_replace("\\", "", json_encode((object) $arr)); 
 }
 else {
 echo "false";
 }
 }
 catch (Exception $e)
 {
 echo $e->getMessage();
 }
 }
 }
?>

This is the android code my colleague wrote:

@Override
protected Boolean doInBackground(Void... params) {
// TODO Auto-generated method stub
boolean status=false;
LoginMgr lmgr=new LoginMgr(getSherlockActivity().getBaseContext());
try {
HttpClient httpclient= new DefaultHttpClient();
HttpGet httpget=new HttpGet("http://www.xxxxx.com/login.php?device=mobi&[email protected]&password=xxxxxxx
");
HttpResponse response= httpclient.execute(httpget);
int statuscode=response.getStatusLine().getStatusCode();
if(statuscode==200){
InputStream is=response.getEntity().getContent();
BufferedReader br=new BufferedReader(new InputStreamReader(is));
final StringBuilder stringbuild= new StringBuilder();
String curr_line;
if((curr_line=br.readLine())!=null){
stringbuild.append(curr_line);
String jsonstr=stringbuild.toString();
getSherlockActivity().runOnUiThread(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
Toast.makeText(getSherlockActivity(), stringbuild.toString(), Toast.LENGTH_LONG).show(); 
}
});
if(!jsonstr.equalsIgnoreCase("false")){
JSONObject job=new JSONObject(jsonstr);
String str=job.getString("3").replace("\\/","/");
String image="http://www.xxxxx.com/img/timthumb.php?&h=50&w=50&src=
"+str;
lmgr.loginUser(new Login(job.getString("0"),job.getString("4"),job.getString("1"),image));
status=true;
JSONObject job=new JSONObject(jsonstr);
if(job.getString("success").equalsIgnoreCase("1")){
lmgr.loginUser(new Login(job.getString("userid"),job.getString("username"),job.getString("useremail"),job.getString("userimage")));
status=true;
} 
}
}
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return status;
}

I have tried using return instead of echo in my code but that still did not work. There were no errors just an empty array.

• colburton: Why are you removing backslashes from the json_encode?
• Blank EDjok: Because there is a url in the returned array, and the json_encode appears to add backslashes to escape certain characters.
• colburton: But it is no longer valid json. You can't decode it anymore.
• Marc B: @blank: don't mess with JSON. You NEVER directly modify a json string, because what you're doing is introducing javascript syntax errors.
• Blank EDjok: Hello i tried all your suggestions but none worked for me.

Answer 1

This should solve your problem. Try to be consistent in what your script returns. It must always returns the same kind of data (JSON) even if it fails.

<?php
include('config.php');
include('functions.php');
include('password_hash_lib/password.php');
if (!isset($_REQUEST["device"]))
{
 $Email = $_POST['Email'];
 $Password = $_POST['Password'];
 try
 {
 if (authenticate($Email, $Password)) echo json_encode(array('auth' => true));
 else echo json_encode(array('auth' => false));
 }
 catch (Exception $e)
 {
 echo json_encode(array('error' => $e->getMessage()));
 }
}
else if (isset($_REQUEST["device"]))
{
 $device = $_REQUEST['device'];
 $Email = $_REQUEST['email'];
 $Password = $_REQUEST['password'];
 if ($device == 'mobi')
 {
 try
 {
 if (authenticate($Email, $Password))
 {
 $curruser = explode("+", $_SESSION['sess_user_auth']);
 $json = array();
 $json['userid'] = $curruser[0];
 $json['email'] = $curruser[1];
 $json['fullname'] = $curruser[2];
 $json['displaypic'] = $curruser[3];
 $json['displayname'] = $curruser[4];
 echo json_encode($json); 
 }
 else
 {
 echo json_encode(array('auth' => false));
 }
 }
 catch (Exception $e)
 {
 echo json_encode(array('error' => $e->getMessage()));
 }
 }
}

EDIT: Based on your last update, you've got some mistakes in your Android code. I've tried to improve it but I haven't tested it.

@Override
protected Boolean doInBackground(Void... params)
{
 boolean status = false;
 LoginMgr lmgr = new LoginMgr(getSherlockActivity().getBaseContext());
 try
 {
 // Connect to the remote server
 HttpClient httpclient = new DefaultHttpClient();
 HttpGet httpget = new HttpGet("http://www.xxxxx.com/login.php?device=mobi&[email protected]&password=xxxxxxx");
 HttpResponse response = httpclient.execute(httpget);
 int statuscode=response.getStatusLine().getStatusCode();
 if(statuscode==200)
 {
 // Read response
 InputStream is = response.getEntity().getContent();
 BufferedReader br = new BufferedReader(new InputStreamReader(is));
 final StringBuilder stringbuild= new StringBuilder();
 String curr_line = null;
 while ((curr_line = br.readLine()) != null)
 {
 stringbuild.append(curr_line);
 }
 getSherlockActivity().runOnUiThread(new Runnable() {
 @Override
 public void run()
 {
 Toast.makeText(getSherlockActivity(), stringbuild.toString(), Toast.LENGTH_LONG).show(); 
 }
 });
 // Parse response to JSON
 JSONObject json = new JSONObject( stringbuild.toString() );
 if (json.has("auth"))
 {
 if (json.getBoolean("auth"))
 {
 // Authentificate with success
 getSherlockActivity().runOnUiThread(new Runnable() {
 @Override
 public void run()
 {
 Toast.makeText(getSherlockActivity(), "Success", Toast.LENGTH_LONG).show(); 
 }
 });
 }
 else
 {
 // In this case, authentification has failed
 getSherlockActivity().runOnUiThread(new Runnable() {
 @Override
 public void run()
 {
 Toast.makeText(getSherlockActivity(), "Wrong user credentials", Toast.LENGTH_LONG).show(); 
 }
 });
 }
 }
 else if (json.has("userid"))
 {
 String userid = json.getString("userid");
 String email = json.getString("email");
 String fullname = json.getString("fullname");
 String displaypic = json.getString("displaypic").replace("\\/","/");
 String displayname = json.getString("displayname");
 // In this case, we got some data about the user
 String image = "http://www.xxxxx.com/img/timthumb.php?&h=50&w=50&src=" + displaypic;
 lmgr.loginUser(new Login(json.getString("0"), json.getString("4"), json.getString("1"), image));
 status = true;
 JSONObject job = new JSONObject(jsonstr);
 if(job.getString("success").equalsIgnoreCase("1"))
 {
 lmgr.loginUser(new Login(userid, fullname, email, displaypic));
 status = true;
 }
 }
 }
 }
 catch (Exception e)
 {
 e.printStackTrace();
 }
 return status;
}

• Blank EDjok: I just edited my post and added the android script as you requested.
• Blank EDjok: Thank you i will try it out, also could you please tell me the mistakes that were made and how you corrected them and why? Just so that they do not happen again. :)
• Manitoba: When you read the server response, you must loop on readLine, in your code you just read it once. Also, you were parsing the json 3 or 4 times in a row.

Answer 2

Replace : echo str_replace("\\", "", json_encode((object) $arr));

By this : echo json_encode(array('user'=>$arr));

Answer 3

I had a similar issue and I changed HttpGet to HttpPost and it worked. Hope this helps