如何从android发送数据到mysql服务器？

Question

I am newbie to the android development. I am using Android Studio. I am making an app in which there is a dropdown list of names. On selecting any name, the corresponding ID of that name is shown at the app. Then there is a button which will search for the user's current gps coordinates and show them on the app. I searched for similar questions and found some links (I will post them at the end) but I couldn't understand them. Below is the screenshot of the app

I have two tables in mysql; users and activity , as shown below

Users

Activity

The UserId is the foreign key in activity table ie the Id from users table will be inserted into it.

I have created following script to return the data as JSON:

<?php
    require_once ('config.php');

    $sql = "SELECT * FROM users";  
    $r = mysqli_query($con,$sql); 
    $result = array();

    while($row = mysqli_fetch_array($r)){
        array_push($result,array(
            'Id'=>$row['Id'],
            'Name'=>$row['Name']
        )); 
      }//end while

    echo json_encode(array('users'=>$result));

    mysqli_close($con);
?>

In my app code I have created a users class

Users Class

public class Users {

private String Id;
private String Name;

public String getId() {
    return Id;
}

public void setId(String id) {
    this.Id = id;
}

public String getName() {
    return Name;
}

public void setName(String name) {
    this.Name = name;
}}

JSON CLASS

public class JSONfunctions {


public static JSONObject getJSONfromURL(String url)
{

    String json = "";
    JSONObject jsonObject = null;
    try
    {
        HttpClient httpClientt = new DefaultHttpClient();
        HttpGet httpGet = new HttpGet(url);
        HttpResponse httpResponse = httpClientt.execute(httpGet);
        BufferedReader br = new BufferedReader(new InputStreamReader(httpResponse.getEntity().getContent()));
        StringBuffer sb = new StringBuffer();
        String line = "";
        while ((line = br.readLine()) != null) {
            sb.append(line);
        }

        json = sb.toString();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    try
    {
        jsonObject = new JSONObject(json);
    } catch (JSONException e) {
        e.printStackTrace();
    }

    return jsonObject;
}

MainActivity

 @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    _latitude = (TextView)findViewById(R.id.latitude);
    _longitude = (TextView)findViewById(R.id.longitude);
    btn_get_coordinates = (Button)findViewById(R.id.button);




    final PermissionListener permissionlistener = new PermissionListener() {
        @Override
        public void onPermissionGranted() {
            //Toast.makeText(MainActivity.this, "Permission Granted", Toast.LENGTH_SHORT).show();

            buildGoogleApiClient();
            //checkLocation(); //check whether location service is enable or not in your  phone
        }

        @Override
        public void onPermissionDenied(ArrayList<String> deniedPermissions) {
            Toast.makeText(MainActivity.this, "Permission Denied\n" + deniedPermissions.toString(), Toast.LENGTH_SHORT).show();
        }
    };

    btn_get_coordinates.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {


            new TedPermission(MainActivity.this)
                    .setPermissionListener(permissionlistener)
                    .setRationaleMessage("This app needs Permission to find your location")
                    .setPermissions(Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION)
                    .check();


        }
    });

    // Download JSON file AsyncTask
    new DownloadJSON().execute();
}

/////////////////////////////////////// Start of Location Services ///////////////////////////////////////////////////////

protected synchronized  void buildGoogleApiClient() {

    mGoogleApiClient = new GoogleApiClient.Builder(this)
            .addConnectionCallbacks(this)
            .addOnConnectionFailedListener(this)
            .addApi(LocationServices.API)
            .build();

    if (mGoogleApiClient != null) {
        mGoogleApiClient.connect();
    } else
        Toast.makeText(this, "Not Connected!", Toast.LENGTH_SHORT).show();

}


/*Ending the updates for the location service*/
@Override
protected void onStop() {
    mGoogleApiClient.disconnect();
    super.onStop();
}

@Override
public void onConnected(@Nullable Bundle bundle) {
    settingRequest();
}

@Override
public void onConnectionSuspended(int i) {
    Toast.makeText(this, "Connection Suspended!", Toast.LENGTH_SHORT).show();
}

@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
    Toast.makeText(this, "Connection Failed!", Toast.LENGTH_SHORT).show();
    if (connectionResult.hasResolution()) {
        try {
            // Start an Activity that tries to resolve the error
            connectionResult.startResolutionForResult(this, 90000);
        } catch (IntentSender.SendIntentException e) {
            e.printStackTrace();
        }
    } else {
        Log.i("Current Location", "Location services connection failed with code " + connectionResult.getErrorCode());
    }
}


/*Method to get the enable location settings dialog*/
public void settingRequest() {
    mLocationRequest = new LocationRequest();
    mLocationRequest.setInterval(10000);    // 10 seconds, in milliseconds
    mLocationRequest.setFastestInterval(1000);   // 1 second, in milliseconds
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

    LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
            .addLocationRequest(mLocationRequest);

    PendingResult<LocationSettingsResult> result =
            LocationServices.SettingsApi.checkLocationSettings(mGoogleApiClient,
                    builder.build());

    result.setResultCallback(new ResultCallback<LocationSettingsResult>() {

        @Override
        public void onResult(@NonNull LocationSettingsResult result) {
            final Status status = result.getStatus();
            final LocationSettingsStates state = result.getLocationSettingsStates();
            switch (status.getStatusCode()) {
                case LocationSettingsStatusCodes.SUCCESS:
                    // All location settings are satisfied. The client can
                    // initialize location requests here.
                    getLocation();
                    break;
                case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                    // Location settings are not satisfied, but this can be fixed
                    // by showing the user a dialog.
                    try {
                        // Show the dialog by calling startResolutionForResult(),
                        // and check the result in onActivityResult().
                        status.startResolutionForResult(MainActivity.this, 1000);
                    } catch (IntentSender.SendIntentException e) {
                        // Ignore the error.
                    }
                    break;
                case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
                    // Location settings are not satisfied. However, we have no way
                    // to fix the settings so we won't show the dialog.
                    break;
            }
        }

    });
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    final LocationSettingsStates states = LocationSettingsStates.fromIntent(data);
    switch (requestCode) {
        case 1000:
            switch (resultCode) {
                case Activity.RESULT_OK:
                    // All required changes were successfully made
                    getLocation();
                    break;
                case Activity.RESULT_CANCELED:
                    // The user was asked to change settings, but chose not to
                    Toast.makeText(this, "Location Service not Enabled", Toast.LENGTH_SHORT).show();
                    break;
                default:
                    break;
            }
            break;
    }
}


public void getLocation() {
    if (ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for ActivityCompat#requestPermissions for more details.
        return;
    } else {
        /*Getting the location after aquiring location service*/
        mLastLocation = LocationServices.FusedLocationApi.getLastLocation(
                mGoogleApiClient);

        if (mLastLocation != null) {
           // _progressBar.setVisibility(View.INVISIBLE);
            _latitude.setText("Latitude: " + String.valueOf(mLastLocation.getLatitude()));
            _longitude.setText("Longitude: " + String.valueOf(mLastLocation.getLongitude()));
        } else {
            /*if there is no last known location. Which means the device has no data for the loction currently.
            * So we will get the current location.
            * For this we'll implement Location Listener and override onLocationChanged*/
            Log.i("Current Location", "No data for location found");

            if (!mGoogleApiClient.isConnected())
                mGoogleApiClient.connect();

            LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, MainActivity.this);
        }
    }
}



@Override
public void onLocationChanged(Location location) {

    mLastLocation = location;
    _progressBar.setVisibility(View.INVISIBLE);
    _latitude.setText("Latitude: " + String.valueOf(mLastLocation.getLatitude()));
    _longitude.setText("Longitude: " + String.valueOf(mLastLocation.getLongitude()));

}

//////////////////////////////////////////// End of Location services ///////////////////////////////////////////////


////////////////////////////////////////// Start of getting JSON DATA ///////////////////////////////////////////////

// Download JSON file AsyncTask
private class DownloadJSON extends AsyncTask<Void, Void, Void>
{

   /* @Override
    protected void onPreExecute() {
        super.onPreExecute();
        progressDialog = new ProgressDialog(MainActivity.this);
        progressDialog.setMessage("Fetching Users....!");
        progressDialog.setCancelable(false);
        progressDialog.show();

    }*/

    @Override
    protected Void doInBackground(Void... params) {

        // Locate the Users Class
        users = new ArrayList<Users>();

        // Create an array to populate the spinner
        userList = new ArrayList<String>();
        // http://10.0.2.2:8000/MobileApp/index.php
        //http://10.0.2.2:8000/app/web/users/
        //http://192.168.100.8:8000/app/web/users/
        // JSON file URL address
        jsonObject = JSONfunctions.getJSONfromURL("http://192.168.100.15:8000/MobileApp/GET_DATA.php");

        try
        {
            JSONObject jobj = new JSONObject(jsonObject.toString());
            // Locate the NodeList name
            jsonArray = jobj.getJSONArray("users");

            for(int i=0; i<jsonArray.length(); i++)
            {
                jsonObject = jsonArray.getJSONObject(i);

                Users user = new Users();

                user.setId(jsonObject.optString("Id"));
                user.setName(jsonObject.optString("Name"));
                users.add(user);

                userList.add(jsonObject.optString("Name"));

            }
        } catch (JSONException e) {
            Log.e("Error", e.getMessage());
            e.printStackTrace();
        }


        return null;
    }

    @Override
    protected void onPostExecute(Void args)
    {
        // Locate the spinner in activity_main.xml
        Spinner spinner = (Spinner)findViewById(R.id.spinner);

        // Spinner adapter
        spinner.setAdapter(new ArrayAdapter<String>(MainActivity.this, android.R.layout.simple_spinner_dropdown_item, userList));

        // Spinner on item click listener

        spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

                textViewResult = (TextView)findViewById(R.id.textView);

                // Set the text followed by the position

                textViewResult.setText("Hi " + users.get(position).getName() + " your ID is " + users.get(position).getId());

            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {
                textViewResult.setText("");
            }
        });
    }


}
//////////////////////////////////////// End of getting JSON DATA //////////////////////////////////////////

When I press the save button the following fields would be inserted into Activity table

1. Id (Which is auto-increment)
2. UserId (User ID from Users table based on the selected name)
3. Latitude (Of current user)
4. Longitude (Of current user)
5. DateTime (Date time of the user)

Should I have to create an 'activity' class like I have created the User class?

For this I have something in mind

1. I would save the data into xml or txt file first then it will be saved into the DB.
2. I should convert the data into json format and then save it into DB
3. Directly save it into the DB by using a query in my php script

Which of these 3 is easiest to implement? It would be very helpful if anyone could provide me a tutorial, though I saw many of them ( 1 , 2 ) and as described above I couldn't understand them :( .

I am stuck to it and don't know what I have to do. Any help would be highly appreciated.

Answer 1

You need to write Api where you can pass the data from android and and fetch that data in Api and store in database using insert query. On android side you have to do below code:

My class PutUtility for getData(), PostData, DeleteData(). you just need to change package name

package fourever.amaze.mics;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.net.URLEncoder;
import java.util.HashMap;
import java.util.Map;


public class PutUtility {

    private Map<String, String> params = new HashMap<>();
    private static HttpURLConnection httpConnection;
    private static BufferedReader reader;
    private static String Content;
    private StringBuffer sb1;
    private StringBuffer response;

    public void setParams(Map<String, String> params) {
        this.params = params;
    }

    public void setParam(String key, String value) {
        params.put(key, value);
    }

    public String getData(String Url) {


        StringBuilder sb = new StringBuilder();

        try {
            // Defined URL  where to send data

            URL url = new URL(Url);

            URLConnection conn = null;
            conn = url.openConnection();

            // Send POST data request
            httpConnection = (HttpURLConnection) conn;
            httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            httpConnection.setRequestMethod("GET");

            BufferedReader in = new BufferedReader(
                    new InputStreamReader(httpConnection.getInputStream()));
            String inputLine;
            response = new StringBuffer();



            while ((inputLine = in.readLine()) != null) {
                response.append(inputLine);
            }
            in.close();

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                reader.close();
            } catch (Exception ex) { }
        }

        return response.toString();
    }


    public String postData(String Url) {


        StringBuilder sb = new StringBuilder();
        for (String key : params.keySet()) {
            String value = null;
            value = params.get(key);


            if (sb.length() > 0) {
                sb.append("&");
            }
            sb.append(key + "=" + value);
        }

        try {
            // Defined URL  where to send data

            URL url = new URL(Url);

            URLConnection conn = null;
            conn = url.openConnection();

            // Send POST data request
            httpConnection = (HttpURLConnection) conn;
            httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            httpConnection.setRequestMethod("POST");
            httpConnection.setDoInput(true);
            httpConnection.setDoOutput(true);
            OutputStreamWriter wr = null;

            wr = new OutputStreamWriter(conn.getOutputStream());
            wr.write(sb.toString());
            wr.flush();

            BufferedReader in = new BufferedReader(
                    new InputStreamReader(httpConnection.getInputStream()));
            String inputLine;
            response = new StringBuffer();

            while ((inputLine = in.readLine()) != null) {
                response.append(inputLine);
            }
            in.close();

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {

                reader.close();
            } catch (Exception ex) {
            }
        }


        return response.toString();
    }


    public String putData(String Url) {


        StringBuilder sb = new StringBuilder();
        for (String key : params.keySet()) {
            String value = null;
            try {
                value = URLEncoder.encode(params.get(key), "UTF-8");
                if (value.contains("+"))
                    value = value.replace("+", "%20");

                //return sb.toString();


                // Get the server response

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

            if (sb.length() > 0) {
                sb.append("&");
            }
            sb.append(key + "=" + value);
        }

        try {
            // Defined URL  where to send data

            URL url = new URL(Url);

            URLConnection conn = null;
            conn = url.openConnection();

            // Send PUT data request
            httpConnection = (HttpURLConnection) conn;
            httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            httpConnection.setRequestMethod("PUT");
            httpConnection.setDoInput(true);
            httpConnection.setDoOutput(false);
            OutputStreamWriter wr = null;

            wr = new OutputStreamWriter(conn.getOutputStream());
            wr.write(sb.toString());
            wr.flush();

            reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            ;
            String line = null;

            // Read Server Response
            while ((line = reader.readLine()) != null) {
                // Append server response in string
                sb1.append(line + " ");
            }

            // Append Server Response To Content String
            Content = sb.toString();


        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {

                reader.close();
            } catch (Exception ex) {
            }
        }
        // Send PUT data request
        return Url;

    }


    public String deleteData(String Url) {


        StringBuilder sb = new StringBuilder();
        for (String key : params.keySet()) {

            try {
                // Defined URL  where to send data

                URL url = new URL(Url);

                URLConnection conn = null;
                conn = url.openConnection();

                // Send POST data request
                httpConnection = (HttpURLConnection) conn;
                httpConnection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
                httpConnection.setRequestMethod("DELETE");
                httpConnection.connect();


                reader = new BufferedReader(new InputStreamReader(conn.getInputStream()));

                String line = null;

                // Read Server Response
                while ((line = reader.readLine()) != null) {
                    // Append server response in string
                    sb1.append(line + " ");
                }

                // Append Server Response To Content String
                Content = sb.toString();


            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {

                    reader.close();
                } catch (Exception ex) {
                }
            }



        }
        return Url;

    }

And use this class like this. this class Automatically do internet connection and give you response from server :

    private class ServiceLogin extends AsyncTask<String, Void, String> {

            ProgressDialog mProgressDialog;
            private String res;

            @Override
            protected void onPreExecute() {
                mProgressDialog = ProgressDialog.show(LoginActivity.this,
                        "", "Please wait...");
            }

            @Override
            protected String doInBackground(String... params) {
                res = null;
                PutUtility put = new PutUtility();

                put.setParam("UserId", params[0].toString());
                put.setParam("Latitude", params[1].toString());
                put.setParam("Longitude", params[2].toString());
                put.setParam("DateTime", params[3].toString());

                try {
                    res = put.postData("INSERT URL of API HERE");
                    Log.v("res", res);
                } catch (Exception e) {
                    e.printStackTrace();
                }
                return res;

            }

            protected void onPostExecute(String res) {
                //"Here you get response from server in res"

            }
        }

Now you can call this service on button click and insert data in service like below:

new ServiceLogin().execute(pass four parameters here);

Hope this helps you

EDIT:

This is simple PHP Api for insert data

<?php include('connection.php');

$return_arr = array();

 $UserId=($_POST['UserId']);
 $Latitude=($_POST['Latitude']);
 $Longitude=($_POST['Longitude']);
$DateTime=($_POST['DateTime']);


        $user_register_sql1 = "INSERT INTO `activity`(`Id`,`UserId`, `Latitude`,`Longitude`,`DateTime`) values (NULL,'".$UserId."','".$Latitude."','".$Longitude."','".$DateTime."')"; 
             mysql_query($user_register_sql1);
             $row_array['errorcode1'] = 1; 

}
?>

Answer 2

You need an api in the server side which will accept json request as POST and it will save data in your Mysql database. You can take any android library like Retrofit and Volley to do request from android side.

Using Retrofit

let's say your pojo is:

public class User {
    private String id;
    private String latitude;
    private String longitude;
public User(String id, String latitude,String longitude) {
    this.id = id;
    this.latitude = latitude;
    this.longitude = longitude
   }
}

Our endpoint would look like the following:

@POST("/users/new")
Call<User> createUser(@Body User user);

Retrofit will take care of JSON yourself. You should have something like:

User user = new User(123, "33.43", "34.34");
Call<User> call = apiService.createuser(user);
call.enqueue(new Callback<User>() {
  @Override
  public void onResponse(Call<User> call, Response<User> response) {

  }

  @Override
  public void onFailure(Call<User> call, Throwable t) {

  }

Answer 3

Here you are using traditional methods to send data To do this way follow below steps.

1) in your build.gradle file add this

useLibrary 'org.apache.http.legacy'

 compile group: 'org.apache.httpcomponents' , name: 'httpclient-android' , version: '4.3.5.1'
    compile('org.apache.httpcomponents:httpmime:4.3') {
        exclude module: "httpclient"}

2) create json parser

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

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;

import android.util.Log;

@SuppressWarnings("deprecation")
public class JSONParser {

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

    // constructor
    public JSONParser() {

    }

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

        // Making HTTP request
        try {
            //Log.d("defaultHttpClient" ,"IN");
            // defaultHttpClient
            DefaultHttpClient httpClient = new DefaultHttpClient();
            //Log.d("url" ,url);
            HttpPost httpPost = new HttpPost(url);
            //Log.d("params" ,params.toString());
            httpPost.setEntity(new UrlEncodedFormEntity(params));
            //Log.d("httpPost" , new UrlEncodedFormEntity(params).toString());
            HttpResponse httpResponse = httpClient.execute(httpPost);
            //Log.e("Entry", "1");
            HttpEntity httpEntity = httpResponse.getEntity();
            //Log.e("Entry", "2");
            is = httpEntity.getContent();
            //Log.e("Entry", "3");  
        } catch (UnsupportedEncodingException e) {
            //Log.e("UnsupportedEncodingException", "UnsupportedEncodingException");
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            //Log.e("ClientProtocolException", "ClientProtocolException");
            e.printStackTrace();
        } catch (IOException e) {
            //Log.e("IOException", "IOException");
            e.printStackTrace();
        }

        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "iso-8859-1"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            //Log.e("Entry", "4");
            while ((line = reader.readLine()) != null) {
                //Log.e("line", line);
                sb.append(line + "\n");
            }
            //Log.e("Entry", "5");
            is.close();
            //Log.e("Entry", "6");
            json = sb.toString();
            //Log.e("JSON", json);
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        // try parse the string to a JSON object
        try {
            if(json.length()>0){
                jObj = new JSONObject(json);
            }else{
                jObj = new JSONObject();
            }
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }

        // return JSON String
        return jObj;

    }
}

3) create on class named as UserFunctions

    public class UserFunctions {
        private JSONParser jsonParser;
        Context ctx ;


        // constructor
        public UserFunctions(Context context){
            ctx = context;
            jsonParser = new JSONParser();
        }

    // create on function to send the value to server and get the json response back
    public JSONObject sendDataToSever(String val1, String val2,String val3){
        JSONObject json = null;
        try {
                // Building Parameters
                List<NameValuePair> params = new ArrayList<NameValuePair>();
                params.add(new BasicNameValuePair("val1", val1));
                params.add(new BasicNameValuePair("val2", val2));
                params.add(new BasicNameValuePair("val3", val3));
                json = jsonParser.getJSONFromUrl(Constants.BASE_URL, params);
           } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            return json;
    }
  }

4) in you main activityclass

// befor onCreate add 
UserFunctions uf;
ProgressDialog pDialog;
JSONObject DATA_JSON;

// in onCreate method

uf = new UserFunctions(Mainactivity.this);

// after getting the location lat and long call AsyncTask to send data to server.

// call asynctask like this here and write the aasyncctask functionality in the end of the class

new LoadWebPageTask().execute();  // calling async task

5) LoadWebPageTask asnc task

private class LoadWebPageTask extends AsyncTask {

protected void onPreExecute() { 
            pDialog = new ProgressDialog(
                    Mainactivity.this);
            pDialog.setMessage("Please wait..");
            pDialog.setIndeterminate(true);
            pDialog.setCancelable(false);
            pDialog.show();
        }

       protected Void doInBackground(Void... unused) {
            runOnUiThread(new Runnable() {
                public void run() {
                    DATA_JSON = uf.sendDataToSever(val1, val2,val3);

                }
            }); 
            return (null);
        }

        protected void onPostExecute(Void unused) {
            // closing progress dialog
            pDialog.dismiss();
           // do your own logics here
        }
    }

This will send data to the server as post method you can process this as post method by using $_POST[];

Please try like this. May this will help you.

For the server side

1) create on Database class

<?php
class Database{

    // specify your own database credentials
    private $host = "localhost";
    private $db_name = "db_name";
    private $username = "root";
    private $password = "password";



    public $conn;

    // get the database connection
    public function getConnection(){

        $this->conn = null;

        try{
            $this->conn = new PDO("mysql:host=" . $this->host . ";dbname=" . $this->db_name, $this->username, $this->password);
        }catch(PDOException $exception){
            echo "Connection error: " . $exception->getMessage();
        }

        return $this->conn;
    }
}
?>

2) create another class to write all DB functionalities here name as Common

<?php
class Common{
    // database connection
    private $conn;  

    // getErrors
    public $error = array();

    public function __construct($db){
        $this->conn = $db;
    }

    // Save error to file
    function save_error($err){
        try {

            if(!is_dir("ERROR")){mkdir("ERROR");}

            $filename = "ERROR/".$this->getDate().".txt";

            if (!$handle = fopen($filename, 'a')) {echo "Cannot open file ($filename)"; return;}

            // Write $somecontent to our opened file.
            if (fwrite($handle, $err."\r\n") === FALSE) {echo "Cannot write to file ($filename)";return;}   

            fclose($handle);
        } catch (Exception $e) {
            echo 'Caught exception: ',  $e->getMessage(), "\n";
        }
    }

    // used for the 'created'
    function getTimestamp(){
        date_default_timezone_set('Asia/Calcutta');
        return  date('Y-m-d H:i:s');
    }

    // used for the 'created'
    function getDate(){
        date_default_timezone_set('Asia/Calcutta');
        return  date('Y-m-d');
    }

// create function to insert data into db

function syncLocalAppData($_tableName, $colName, $values){
        try{

            $query = " REPLACE INTO  ".$_tableName." (".$colName.") VALUES (".$values."); ";
            //echo $query;
            //exit;

            $stmt = $this->conn->prepare( $query );


            if($stmt->execute()){
                return true;
            }else{
                save_error("\r\nQRY : " . $stmt->queryString . " \r\n ERR CODE : " . $stmt->errorCode() . " \r\n ERR  : " .  json_encode($stmt->errorInfo()));
                 return false;
            }           

        } catch (Exception $e){
            save_error("\r\nOTHR : " . $e->getMessage());
            return false;
        }
    }
}

?>

3) create on php file to process the post data userApi.php

<?php
$_errAry = array("status"=>400, "success"=>"false", "message"=>"Can't Service your request ","data"=>array()); // error reprting json
$_sucAry = array("status"=>200, "success"=>"true", "message"=>"","data"=>array()); // sccess rrespose json


nclude_once 'database.php';

// get database connection
$database = new Database();
$db = $database->getConnection();



// instantiate Common Objects
include_once 'objects/common.class.php';

$_tbl=""; $_cols="";  $_ord=""; 
$_whr="  ";


if(isset($_POST["val1"],$_POST["val2"],$_POST["val3"])){

$val1=$_POST["val1"];
$val2=$_POST["val2"];
$val3=$_POST["val3"];

$tableName="yourTableName";
$ColNameString="your coma separated coloumns name";
$ValueString="'".$val1."','".$val2."','".$val3."';
$_comm = new Common($db);
            $return=$_comm-> syncLocalAppData($tableName,$ColNameString,$ValueString);
if($return){
        $_op = $_sucAry;
        $_op["data"]=array("status"=>true),
        echo json_encode($_op);
        exit(0);
}else{
        $_op = $_sucAry;
        $_op["success"]= "false";
        $_op["message"]="cant process your request,
        echo json_encode($_op);exit(0);
}
}

Answer 4

Should i have to create a activity class same as i created user class?

Yes.

The easiest solution is convert your activity object into a JSON object. Send it via a post request with your HTTP lib (I would recommend using OKHttp http://square.github.io/okhttp/ ). And finally write a php script wich will handle the request, get the object from the JSON and save it into your database.