android - How to getback response from server

Question

I am doing an android app which requires email verification before moving further.I have a simple edittext field where user enters their email and clicks to proceed button.On clicking to proceed button I have sent that email to server.I wish in backend the email user sends get checked first.If the email is available in the database of verified emails then the user is allowed to Proceed to next activity,else user should get some messeges that their email isn't verified.For this I did this in my android app java class

  package fragment;


import android.app.Activity;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import com.example.user.timothysurvey.R;
import com.example.user.timothysurvey.activity.Introduction;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

import pojo.Email;
import pojo.JSONParser;

/**
 * A simple {@link Fragment} subclass.
 */
public class Ongoing extends Fragment {


    Button proceed;
    EditText email;
    TextView surveyTitle;
    String success;

    private static final String url="http://192.168.0.123/survey/public/api/verifyemail";

    public Ongoing() {
        // Required empty public constructor
    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View v=inflater.inflate(R.layout.fragment_ongoing, container, false);
        surveyTitle= (TextView) v.findViewById(R.id.surveyTitle);
        email = (EditText) v.findViewById(R.id.email);
        proceed= (Button) v.findViewById(R.id.proceed);
        proceed.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(isConnected()) {

                    String emailAddress = email.getText().toString().trim();
                    String emailPattern = "[a-zA-Z0-9._-]+@[a-z]+\.+[a-z]+";

                    if (emailAddress.matches("")) {

                        Toast.makeText(getContext(), "Please fill up all the fields", Toast.LENGTH_LONG).show();

                    } else {
                        if (emailAddress.matches(emailPattern)) {
                            new HttpAsyncTask().execute("http://192.168.0.123/survey/public/api/verifyemail");
                        } else
                            Toast.makeText(getContext(), "Invalid Email Address", Toast.LENGTH_LONG).show();
                    }
                }
            else {

                Toast.makeText(getContext(), "Please check your internet connection", Toast.LENGTH_LONG).show();
            }
            }
        });
        return v;
    }

    private class HttpAsyncTask extends AsyncTask<String, Void, String> {
        @Override
        protected String doInBackground(String... urls) {

            List<NameValuePair> params = new ArrayList<NameValuePair>();
            params.add(new BasicNameValuePair("email", email.getText().toString()));
            JSONParser jParser = new JSONParser();
            JSONObject json = jParser.makeHttpRequest(url, "POST", params);
            try {
                success = json.getString("success");
            } catch (JSONException e) {
                e.printStackTrace();
            }
            return null;
        }
        @Override
        protected void onPostExecute(String result) {
            if(success.equals("Email verified. Please proceed with survey"))
                Toast.makeText(getContext(), "Wait For a moment", Toast.LENGTH_LONG).show();
        }
    }

    public boolean isConnected(){
        ConnectivityManager connMgr = (ConnectivityManager) getActivity().getSystemService(Activity.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
        if (networkInfo != null && networkInfo.isConnected())
            return true;
        else
            return false;
    }

}

And this is my php code for the backend

<?php

use IlluminateHttpRequest;

/*
|--------------------------------------------------------------------------
| API Routes
|--------------------------------------------------------------------------
|
| Here is where you can register API routes for your application. These
| routes are loaded by the RouteServiceProvider within a group which
| is assigned the "api" middleware group. Enjoy building your API!
|
 */

// url
// :: localhost/api/verifyemail/[email protected]

// messages
// 1. No record in database
// 2. Admin has not verified your email
// 3. Email verified. Please proceed with survey

Route::get('verifyemail/{email}', function ($email) {
    // first check whether user exist in database
    $user = AppSurveyUser::where('email', $email)->first();

    // if user does not exist send error message
    if (empty($user)) {
        $user['error'] = 'No record in database';
    } else {
        if ($user->verified_by_admin) {
            $user['success'] = 'Email verified. Please proceed with survey';
        } else {
            $user['error'] = 'Admin has not verified your email';
        }
    }

    return $user;
    // if exist check whether he is allowed to take survey or not
});

Route::post('verifyemail', function (Request $request) {
    // check email
    $email = $request->email;

    $user = AppSurveyUser::where('email', $email)->first();
    if (empty($user)) {
        $user['error'] = 'No record in database';
    } else {
        if ($user->verified_by_admin) {
            $user['success'] = 'Email verified. Please proceed with survey';
        } else {
            $user['error'] = 'Admin has not verified your email';
        }
    }
    return $user;
});

Route::get('/user', function (Request $request) {
    return $request->user();
})->middleware('auth:api');

I am not getting any result from above code.Somebody Please suggest me the right way I could achieve my target.Thank you in advance

Answer 1

Define a global string variable :

Button proceed;
EditText email;
TextView surveyTitle;
String success;

Update HttpAsyncTask like this :

private class HttpAsyncTask extends AsyncTask<String, Void, String> {
    @Override
    protected String doInBackground(String... urls) {

        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("email", email.getText().toString()));
        JSONParser jParser = new JSONParser();
        JSONObject json = jParser.makeHttpRequest(url, "POST", params);
        try {
            success = json.getString("success");
        } catch (JSONException e) {
            e.printStackTrace();
        }
        return null;
    }
    @Override
    protected void onPostExecute(String result) {
        if(success.equals("Email verified. Please proceed with survey"))
            Toast.makeText(getContext(), "Wait For a moment", Toast.LENGTH_LONG).show();
    }
}

And finally create JSONParser class like this :

public class JSONParser {

static InputStream is = null;
static JSONObject jObj = null;
static String json = "";

public JSONParser() {

}

public JSONObject getJSONFromUrl(final String url) {

    try {
        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpPost httpPost = new HttpPost(url);
        HttpResponse httpResponse = httpClient.execute(httpPost);
        HttpEntity httpEntity = httpResponse.getEntity();
        is = httpEntity.getContent();
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    try {
        BufferedReader reader = new BufferedReader(new InputStreamReader(
                is, "iso-8859-1"), 8);
        StringBuilder sb = new StringBuilder();
        String line = null;

        while ((line = reader.readLine()) != null) {
            sb.append(line + "
");
        }

        is.close();
        json = sb.toString();
    } catch (Exception e) {
        Log.e("Buffer Error", "Error converting result " + e.toString());
    }

    try {
        jObj = new JSONObject(json);
    } catch (JSONException e) {
        Log.e("JSON Parser", "Error parsing data " + e.toString());
    }

    return jObj;

}

public JSONObject makeHttpRequest(String url, String method,
        List<NameValuePair> params) {

    try {

        if (method == "POST") {
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url);
            httpPost.setEntity(new UrlEncodedFormEntity(params));

            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();

        } else if (method == "GET") {
            DefaultHttpClient httpClient = new DefaultHttpClient();
            String paramString = URLEncodedUtils.format(params, "utf-8");
            url += "?" + paramString;
            HttpGet httpGet = new HttpGet(url);

            HttpResponse httpResponse = httpClient.execute(httpGet);
            HttpEntity httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();
        }

    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    try {
        BufferedReader reader = new BufferedReader(new InputStreamReader(
                is, "iso-8859-1"), 8);
        StringBuilder sb = new StringBuilder();
        String line = null;
        while ((line = reader.readLine()) != null) {
            sb.append(line + "
");
        }
        is.close();
        json = sb.toString();
    } catch (Exception e) {
        Log.e("Buffer Error", "Error converting result " + e.toString());
    }

    try {
        jObj = new JSONObject(json);
    } catch (JSONException e) {
        Log.e("JSON Parser", "Error parsing data " + e.toString());
    }

    return jObj;
} }