Envoi de données POST dans Android

J'ai de l'expérience avec PHP, JavaScript et beaucoup d'autres langages de script, mais je n'ai pas beaucoup d'expérience avec Java ou Android.

Je cherche un moyen d'envoyer des données POST à un script PHP et d'afficher le résultat.

* Réponse mise à jour qui fonctionne sur Android 6.0+. Merci à @Rohit Suthar , @Tamis Bolvari et @sudhiskr pour les commentaires. *

    public class CallAPI extends AsyncTask<String, String, String> {

        public CallAPI(){
            //set context variables if required
        }

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }

         @Override
         protected String doInBackground(String... params) {
            String urlString = params[0]; // URL to call
            String data = params[1]; //data to post
            OutputStream out = null;

            try {
                URL url = new URL(urlString);
                HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
                out = new BufferedOutputStream(urlConnection.getOutputStream());

                BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(out, "UTF-8"));
                writer.write(data);
                writer.flush();
                writer.close();
                out.close();

                urlConnection.connect();
            } catch (Exception e) {
                System.out.println(e.getMessage());
            }
        }
    }

Références:

• https://developer.android.com/reference/java/net/HttpURLConnection.html
• Comment ajouter des paramètres à HttpURLConnection à l'aide de POST à ​​l'aide de NameValuePair

Réponse plus ancienne

Remarque: cette solution est obsolète. Il ne fonctionne que sur les appareils Android jusqu'à 5.1. Android 6.0 et supérieur n'incluent pas le client Apache http utilisé dans cette réponse.

Le client Http d'Apache Commons est le chemin à parcourir. Il est déjà inclus dans Android. Voici un exemple simple de la façon d'utiliser HTTP Post en l'utilisant.

public void postData() {
    // Create a new HttpClient and Post Header
    HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost("http://www.yoursite.com/script.php");

    try {
        // Add your data
        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
        nameValuePairs.add(new BasicNameValuePair("id", "12345"));
        nameValuePairs.add(new BasicNameValuePair("stringdata", "Hi"));
        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

        // Execute HTTP Post Request
        HttpResponse response = httpclient.execute(httppost);

    } catch (ClientProtocolException e) {
        // TODO Auto-generated catch block
    } catch (IOException e) {
        // TODO Auto-generated catch block
    }
} 

pour Android => 5

Les classes org.apache.http et AndroidHttpClient sont obsolètes dans Android 5.1 . Ces classes ne sont plus maintenues et vous devez migrer tout code d'application utilisant ces API vers les classes URLConnection dès que possible.

https://developer.android.com/about/versions/android-5.1.html#http

Pensé à partager mon code en utilisant HttpUrlConnection

public String  performPostCall(String requestURL,
        HashMap<String, String> postDataParams) {

    URL url;
    String response = "";
    try {
        url = new URL(requestURL);

        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setReadTimeout(15000);
        conn.setConnectTimeout(15000);
        conn.setRequestMethod("GET");
        conn.setDoInput(true);
        conn.setDoOutput(true);


        OutputStream os = conn.getOutputStream();
        BufferedWriter writer = new BufferedWriter(
                new OutputStreamWriter(os, "UTF-8"));
        writer.write(getPostDataString(postDataParams));

        writer.flush();
        writer.close();
        os.close();
        int responseCode=conn.getResponseCode();

        if (responseCode == HttpsURLConnection.HTTP_OK) {
            String line;
            BufferedReader br=new BufferedReader(new InputStreamReader(conn.getInputStream()));
            while ((line=br.readLine()) != null) {
                response+=line;
            }
        }
        else {
            response="";    

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

    return response;
}

...

private String getPostDataString(HashMap<String, String> params) throws UnsupportedEncodingException{
        StringBuilder result = new StringBuilder();
        boolean first = true;
        for(Map.Entry<String, String> entry : params.entrySet()){
            if (first)
                first = false;
            else
                result.append("&");

            result.append(URLEncoder.encode(entry.getKey(), "UTF-8"));
            result.append("=");
            result.append(URLEncoder.encode(entry.getValue(), "UTF-8"));
        }

        return result.toString();
    }

vous pouvez également poster la méthode:

conn.setRequestMethod("POST");

Mise à jour 21/02/2016

pour la demande de publication avec json , voir cet exemple:

public class Empty extends
        AsyncTask<Void, Void, Boolean> {

    String urlString = "http://www.yoursite.com/";

    private final String TAG = "post json example";
    private Context context;

    private int advertisementId;

    public Empty(Context contex, int advertisementId) {

        this.context = contex;
        this.advertisementId = advertisementId;
    }

    @Override
    protected void onPreExecute() {
        Log.e(TAG, "1 - RequestVoteTask is about to start...");

    }

    @Override
    protected Boolean doInBackground(Void... params) {
        boolean status = false;

        String response = "";
        Log.e(TAG, "2 - pre Request to response...");

        try {
            response = performPostCall(urlString, new HashMap<String, String>() {

                        private static final long serialVersionUID = 1L;

                        {
                            put("Accept", "application/json");
                            put("Content-Type", "application/json");
                        }
                    });
            Log.e(TAG, "3 - give Response...");
            Log.e(TAG, "4 " + response.toString());
        } catch (Exception e) {
            // displayLoding(false);

            Log.e(TAG, "Error ...");
        }
        Log.e(TAG, "5 - after Response...");

        if (!response.equalsIgnoreCase("")) {
            try {
                Log.e(TAG, "6 - response !empty...");
                //
                JSONObject jRoot = new JSONObject(response);
                JSONObject d = jRoot.getJSONObject("d");

                int ResultType = d.getInt("ResultType");
                Log.e("ResultType", ResultType + "");

                if (ResultType == 1) {

                    status = true;

                }

            } catch (JSONException e) {
                // displayLoding(false);
                // e.printStackTrace();
                Log.e(TAG, "Error " + e.getMessage());
            } finally {

            }
        } else {
            Log.e(TAG, "6 - response is empty...");

            status = false;
        }

        return status;
    }

    @Override
    protected void onPostExecute(Boolean result) {
        //
        Log.e(TAG, "7 - onPostExecute ...");

        if (result) {
            Log.e(TAG, "8 - Update UI ...");

            // setUpdateUI(adv);
        } else {
            Log.e(TAG, "8 - Finish ...");

            // displayLoding(false);
            // finish();
        }

    }

    public String performPostCall(String requestURL,
                                  HashMap<String, String> postDataParams) {

        URL url;
        String response = "";
        try {
            url = new URL(requestURL);

            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setReadTimeout(context.getResources().getInteger(
                    R.integer.maximum_timeout_to_server));
            conn.setConnectTimeout(context.getResources().getInteger(
                    R.integer.maximum_timeout_to_server));
            conn.setRequestMethod("POST");
            conn.setDoInput(true);
            conn.setDoOutput(true);

            conn.setRequestProperty("Content-Type", "application/json");

            Log.e(TAG, "11 - url : " + requestURL);

            /*
             * JSON
             */

            JSONObject root = new JSONObject();
            //
            String token = Static.getPrefsToken(context);

            root.put("securityInfo", Static.getSecurityInfo(context));
            root.put("advertisementId", advertisementId);

            Log.e(TAG, "12 - root : " + root.toString());

            String str = root.toString();
            byte[] outputBytes = str.getBytes("UTF-8");
            OutputStream os = conn.getOutputStream();
            os.write(outputBytes);

            int responseCode = conn.getResponseCode();

            Log.e(TAG, "13 - responseCode : " + responseCode);

            if (responseCode == HttpsURLConnection.HTTP_OK) {
                Log.e(TAG, "14 - HTTP_OK");

                String line;
                BufferedReader br = new BufferedReader(new InputStreamReader(
                        conn.getInputStream()));
                while ((line = br.readLine()) != null) {
                    response += line;
                }
            } else {
                Log.e(TAG, "14 - False - HTTP_OK");
                response = "";
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return response;
    }
}

MISE À JOUR 24/08/2016

Utilisez la meilleure bibliothèque, comme:

• Retrofit
• Volée

car :

• Évitez HttpUrlConnection et HttpClient

Sur des niveaux d'API inférieurs (principalement sur Gingerbread et Froyo), HttpUrlConnection et HttpClient sont loin d'être parfaits

• Et évitez aussi AsyncTask
• Ils sont beaucoup plus rapides
• Ils mettent tout en cache

Depuis l'introduction de Honeycomb (API 11), il est obligatoire d'effectuer des opérations réseau sur un thread séparé, différent du thread principal

De cette façon, nous pouvons envoyer des données avec la méthode http post et obtenir le résultat

     public class MyHttpPostProjectActivity extends Activity implements OnClickListener {

    private EditText usernameEditText;
    private EditText passwordEditText;
    private Button sendPostReqButton;
    private Button clearButton;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.login);

        usernameEditText = (EditText) findViewById(R.id.login_username_editText);
        passwordEditText = (EditText) findViewById(R.id.login_password_editText);

        sendPostReqButton = (Button) findViewById(R.id.login_sendPostReq_button);
        sendPostReqButton.setOnClickListener(this);

        clearButton = (Button) findViewById(R.id.login_clear_button);
        clearButton.setOnClickListener(this);        
    }

    @Override
    public void onClick(View v) {

        if(v.getId() == R.id.login_clear_button){
            usernameEditText.setText("");
            passwordEditText.setText("");
            passwordEditText.setCursorVisible(false);
            passwordEditText.setFocusable(false);
            usernameEditText.setCursorVisible(true);
            passwordEditText.setFocusable(true);
        }else if(v.getId() == R.id.login_sendPostReq_button){
            String givenUsername = usernameEditText.getEditableText().toString();
            String givenPassword = passwordEditText.getEditableText().toString();

            System.out.println("Given username :" + givenUsername + " Given password :" + givenPassword);

            sendPostRequest(givenUsername, givenPassword);
        }   
    }

    private void sendPostRequest(String givenUsername, String givenPassword) {

        class SendPostReqAsyncTask extends AsyncTask<String, Void, String>{

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

                String paramUsername = params[0];
                String paramPassword = params[1];

                System.out.println("*** doInBackground ** paramUsername " + paramUsername + " paramPassword :" + paramPassword);

                HttpClient httpClient = new DefaultHttpClient();

                // In a POST request, we don't pass the values in the URL.
                //Therefore we use only the web page URL as the parameter of the HttpPost argument
                HttpPost httpPost = new HttpPost("http://www.nirmana.lk/hec/android/postLogin.php");

                // Because we are not passing values over the URL, we should have a mechanism to pass the values that can be
                //uniquely separate by the other end.
                //To achieve that we use BasicNameValuePair             
                //Things we need to pass with the POST request
                BasicNameValuePair usernameBasicNameValuePair = new BasicNameValuePair("paramUsername", paramUsername);
                BasicNameValuePair passwordBasicNameValuePAir = new BasicNameValuePair("paramPassword", paramPassword);

                // We add the content that we want to pass with the POST request to as name-value pairs
                //Now we put those sending details to an ArrayList with type safe of NameValuePair
                List<NameValuePair> nameValuePairList = new ArrayList<NameValuePair>();
                nameValuePairList.add(usernameBasicNameValuePair);
                nameValuePairList.add(passwordBasicNameValuePAir);

                try {
                    // UrlEncodedFormEntity is an entity composed of a list of url-encoded pairs. 
                    //This is typically useful while sending an HTTP POST request. 
                    UrlEncodedFormEntity urlEncodedFormEntity = new UrlEncodedFormEntity(nameValuePairList);

                    // setEntity() hands the entity (here it is urlEncodedFormEntity) to the request.
                    httpPost.setEntity(urlEncodedFormEntity);

                    try {
                        // HttpResponse is an interface just like HttpPost.
                        //Therefore we can't initialize them
                        HttpResponse httpResponse = httpClient.execute(httpPost);

                        // According to the JAVA API, InputStream constructor do nothing. 
                        //So we can't initialize InputStream although it is not an interface
                        InputStream inputStream = httpResponse.getEntity().getContent();

                        InputStreamReader inputStreamReader = new InputStreamReader(inputStream);

                        BufferedReader bufferedReader = new BufferedReader(inputStreamReader);

                        StringBuilder stringBuilder = new StringBuilder();

                        String bufferedStrChunk = null;

                        while((bufferedStrChunk = bufferedReader.readLine()) != null){
                            stringBuilder.append(bufferedStrChunk);
                        }

                        return stringBuilder.toString();

                    } catch (ClientProtocolException cpe) {
                        System.out.println("First Exception caz of HttpResponese :" + cpe);
                        cpe.printStackTrace();
                    } catch (IOException ioe) {
                        System.out.println("Second Exception caz of HttpResponse :" + ioe);
                        ioe.printStackTrace();
                    }

                } catch (UnsupportedEncodingException uee) {
                    System.out.println("An Exception given because of UrlEncodedFormEntity argument :" + uee);
                    uee.printStackTrace();
                }

                return null;
            }

            @Override
            protected void onPostExecute(String result) {
                super.onPostExecute(result);

                if(result.equals("working")){
                    Toast.makeText(getApplicationContext(), "HTTP POST is working...", Toast.LENGTH_LONG).show();
                }else{
                    Toast.makeText(getApplicationContext(), "Invalid POST req...", Toast.LENGTH_LONG).show();
                }
            }           
        }

        SendPostReqAsyncTask sendPostReqAsyncTask = new SendPostReqAsyncTask();
        sendPostReqAsyncTask.execute(givenUsername, givenPassword);     
    }
}

Voici un exemple de la façon de POSTER des données en plusieurs parties SANS utiliser de bibliothèques Apache externes:

byte[] buffer = getBuffer();

if(buffer.length > 0) {
   String lineEnd = "\r\n"; 
   String twoHyphens = "--"; 
   String boundary =  "RQdzAAihJq7Xp1kjraqf"; 

   ByteArrayOutputStream baos = new ByteArrayOutputStream();
   DataOutputStream dos = new DataOutputStream(baos);

   // Send parameter #1
   dos.writeBytes(twoHyphens + boundary + lineEnd); 
   dos.writeBytes("Content-Disposition: form-data; name=\"param1\"" + lineEnd);
   dos.writeBytes("Content-Type: text/plain; charset=US-ASCII" + lineEnd);
   dos.writeBytes("Content-Transfer-Encoding: 8bit" + lineEnd);
   dos.writeBytes(lineEnd);
   dos.writeBytes(myStringData + lineEnd);

   // Send parameter #2
   //dos.writeBytes(twoHyphens + boundary + lineEnd); 
   //dos.writeBytes("Content-Disposition: form-data; name=\"param2\"" + lineEnd + lineEnd);
   //dos.writeBytes("foo2" + lineEnd);

   // Send a binary file
   dos.writeBytes(twoHyphens + boundary + lineEnd); 
   dos.writeBytes("Content-Disposition: form-data; name=\"param3\";filename=\"test_file.dat\"" + lineEnd); 
   dos.writeBytes("Content-Type: application/octet-stream" + lineEnd);
   dos.writeBytes("Content-Transfer-Encoding: binary" + lineEnd);
   dos.writeBytes(lineEnd); 
   dos.write(buffer);
   dos.writeBytes(lineEnd); 
   dos.writeBytes(twoHyphens + boundary + twoHyphens + lineEnd); 
   dos.flush(); 
   dos.close();

   ByteArrayInputStream content = new ByteArrayInputStream(baos.toByteArray());
   BasicHttpEntity entity = new BasicHttpEntity();
   entity.setContent(content);

   HttpPost httpPost = new HttpPost(myURL);
   httpPost.addHeader("Connection", "Keep-Alive");
   httpPost.addHeader("Content-Type", "multipart/form-data; boundary="+boundary);

   //MultipartEntity entity = new MultipartEntity();
   //entity.addPart("param3", new ByteArrayBody(buffer, "test_file.dat"));
   //entity.addPart("param1", new StringBody(myStringData));

   httpPost.setEntity(entity);

   /*
   String httpData = "";
   ByteArrayOutputStream baos1 = new ByteArrayOutputStream();
   entity.writeTo(baos1);
   httpData = baos1.toString("UTF-8");
   */

   /*
   Header[] hdrs = httpPost.getAllHeaders();
   for(Header hdr: hdrs) {
     httpData += hdr.getName() + " | " + hdr.getValue() + " |_| ";
   }
   */

   //Log.e(TAG, "httpPost data: " + httpData);
   response = httpClient.execute(httpPost);
}

à la réponse @primpop j'ajouterais comment convertir la réponse dans une chaîne:

HttpResponse response = client.execute(request);
HttpEntity entity = response.getEntity();
if (entity != null) {
    InputStream instream = entity.getContent();

    String result = RestClient.convertStreamToString(instream);
    Log.i("Read from server", result);
}

Voici un exemple de convertStramToString .

Mieux vaut utiliser Apache Commons HttpClient, qui est également déjà inclus dans Android. Jetez un œil au développeur Android: Résumé du package du client HTTP Apache pour obtenir des informations générales sur l'API.

Vous pouvez l'utiliser pour envoyer une demande HTTP POST à ​​une URL. Vous pouvez facilement envoyer une demande et obtenir une réponse. J'utilise toujours ça. Je travaille bien pour moi.

  ///////////////////// Check SubScription ////////////////////

        try {
                                 AsyncHttpClient client = new AsyncHttpClient();
                                   // Http Request Params Object
                                   RequestParams params = new RequestParams();
                                   String u = "B2mGaME";
                                   String au = "gamewrapperB2M";
                                   // String mob = "880xxxxxxxxxx";
                                   params.put("usr", u.toString());
                                   params.put("aut", au.toString());
                                   params.put("uph", MobileNo.toString());
                                   //  params.put("uph", mob.toString());
                                                client.post("http://196.6.13.01:88/ws/game_wrapper_reg_check.php", params, new AsyncHttpResponseHandler() {
                                       @Override
                                       public void onSuccess(String response) {
                                           playStatus = response;
                                        //////Get your Response/////
                                           Log.i(getClass().getSimpleName(), "Response SP Status. " + playStatus);
                                       }
                   @Override
                   public void onFailure(Throwable throwable) {
                       super.onFailure(throwable);
                   }
                                   });
                               } catch (Exception e) {
                                   e.printStackTrace();
                               }

Vous devez également ajouter un fichier Jar ci-dessous dans les bibliothèques

android-async-http-1.3.1.jar

Enfin éditez votre build.gradle

dependencies {
    compile files('libs/<android-async-http-1.3.1.jar>')

}

Dans le dernier Reconstruisez votre projet.

Utilisez la okHttpbibliothèque open source de Square. okHttpfonctionne à partir d'Android 2.3 et plus et dispose d'une licence Apache 2.0 sur GitHub .

L'envoi de données POST est aussi simple que l'ajout de ce qui suit dans une AsyncTask:

OkHttpClient client = new OkHttpClient();
RequestBody formBody = new FormBody.Builder()
                      .add("email", emailString) // A sample POST field
                      .add("comment", commentString) // Another sample POST field
                      .build();
Request request = new Request.Builder()
                 .url("https://yourdomain.org/callback.php") // The URL to send the data to
                 .post(formBody)
                 .build();

okHttppossède également un espace de noms sur maven, il est donc simple de l'ajouter à votre projet Android Studio. Ajoutez simplement compile 'com.squareup.okhttp3:okhttp:3.11.0'à build.gradle de votre application.

Code complet

Ajoutez les éléments suivants à votre activité:

public class CallAPI extends AsyncTask<String, String, String> {

    String emailString;
    String commentString;

    public CallAPI(String email, String commnt){
           emailString = email;
           commentString = commnt;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected String doInBackground(String... params) {
        OkHttpClient client = new OkHttpClient();
        RequestBody formBody = new FormBody.Builder()
                      .add("email", emailString) // A sample POST field
                      .add("comment", commentString) // Another sample POST field
                      .build();
        Request request = new Request.Builder()
                 .url("https://yourdomain.org/callback.php") // The URL to send the data to
                 .post(formBody)
                 .build();
        return "";
    }

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);
    }
}

Et appelez-le en utilisant:

new CallAPI(emailString, commentString).execute();

Pour moi travaille ensuite:

 private sendData() {
     JSONObject jsonObject = new JSONObject();
     jsonObject.accumulate("key1", value1);
     jsonObject.accumulate("key2", value2);

     boolean success = sendPost(SERVER_URL + "/v1/auth", jsonObject);
 }

 private boolean sendPost(String url, JSONObject parameters) {
        boolean requestResult = false;
        InputStream inputStream = null;
        String result = "";
        try {

            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url);

            String json = "";

            json = parameters.toString();

            StringEntity se = new StringEntity(json);
            httpPost.setEntity(se);

            httpPost.setHeader("Accept", "application/json");
            httpPost.setHeader("Content-type", "application/json");

            HttpResponse httpResponse = httpclient.execute(httpPost);

            inputStream = httpResponse.getEntity().getContent();

            if (inputStream != null) {
                result = convertInputStreamToString(inputStream);
                requestResult = true;
            } else {
                result = "Did not work!";
                requestResult = false;
            }
            System.out.println(result);
        } catch (Exception e) {
            Log.d("InputStream", e.getLocalizedMessage());
            requestResult = false;
        }
        return requestResult;
    }

Vous pouvez utiliser URLConnectionavec , (pour envoyer des données) et (pour recevoir). Sun a un exemple pour exactement cela .setDoOutput(true)getOutputStream() getInputStream()

Si vous souhaitez simplement ajouter des données à l'URL, vous pouvez le faire en utilisant HttpUrlConnection, car HttpClient est désormais obsolète. Une meilleure façon serait d’utiliser une bibliothèque comme

Rénovation de Volley

Nous pouvons publier des données dans le script php et récupérer le résultat et l'afficher en utilisant ce code effectué via la classe AsyncTask.

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

    // Required initialization


    private String Content;
    private String Error = null;
    private ProgressDialog Dialog = new ProgressDialog(Login.this);
    String data ="";
    int sizeData = 0;



    protected void onPreExecute() {
        // NOTE: You can call UI Element here.

        //Start Progress Dialog (Message)

        Dialog.setMessage("Please wait..");
        Dialog.show();
        Dialog.setCancelable(false);
        Dialog.setCanceledOnTouchOutside(false);

        try{
            // Set Request parameter
            data +="&" + URLEncoder.encode("username", "UTF-8") + "="+edittext.getText();



        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

    // Call after onPreExecute method
    protected Void doInBackground(String... urls) {

        /************ Make Post Call To Web Server ***********/
        BufferedReader reader=null;

        // Send data
        try
        {

            // Defined URL  where to send data
            URL url = new URL(urls[0]);

            // Send POST data request

            URLConnection conn = url.openConnection();

            conn.setConnectTimeout(5000);//define connection timeout 
            conn.setReadTimeout(5000);//define read timeout
            conn.setDoOutput(true);
            OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
            wr.write( data );
            wr.flush();

            // Get the server response

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



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

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


        }
        catch(Exception ex)
        {
            Error = ex.getMessage();
        }
        finally
        {
            try
            {

                reader.close();
            }

            catch(Exception ex) {}
        }


        return null;
    }

    protected void onPostExecute(Void unused) {
        // NOTE: You can call UI Element here.

        // Close progress dialog
        Dialog.dismiss();

        if (Error != null) {

                Toast.makeText(getApplicationContext(),"Error encountered",Toast.LENGTH_LONG).show();



        }
        else {




            try {

                JSONObject jsonRootObject = new JSONObject(Content);


                JSONObject json2 =jsonRootObject.getJSONObject("jsonkey");//pass jsonkey here


                String id =json2.optString("id").toString();//parse json to string through parameters


     //the result is stored in string id. you can display it now


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


        }

    }

}

Mais l'utilisation de bibliothèques telles que volley ou retrofit est une bien meilleure option car la classe Asynctask et HttpurlConnection sont plus lentes que les bibliothèques. De plus, la bibliothèque va tout récupérer et est également plus rapide.

J'ai trouvé cet exemple utile avec ce didacticiel vidéo.

Classe de connecteur:

package com.tutorials.hp.mysqlinsert;
import java.io.IOException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
/**
 * Created by Oclemmy on 3/31/2016 for ProgrammingWizards Channel.
 */
public class Connector {
    /*
 1.SHALL HELP US ESTABLISH A CONNECTION TO THE NETWORK
 2. WE ARE MAKING A POST REQUEST
  */
    public static HttpURLConnection connect(String urlAddress) {
        try
        {
            URL url=new URL(urlAddress);
            HttpURLConnection con= (HttpURLConnection) url.openConnection();
            //SET PROPERTIES
            con.setRequestMethod("POST");
            con.setConnectTimeout(20000);
            con.setReadTimeout(20000);
            con.setDoInput(true);
            con.setDoOutput(true);
            //RETURN
            return con;
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }
 }

Classe DataPackager:

package com.tutorials.hp.mysqlinsert;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.Iterator;
/**
 * Created by Oclemmy on 3/31/2016 for ProgrammingWizards Channel.
 * 1.BASICALLY PACKS DATA WE WANNA SEND
 */
public class DataPackager {
    String name,position,team;
    /*
    SECTION 1.RECEIVE ALL DATA WE WANNA SEND
     */
    public DataPackager(String name, String position, String team) {
        this.name = name;
        this.position = position;
        this.team = team;
    }
    /*
   SECTION 2
   1.PACK THEM INTO A JSON OBJECT
   2. READ ALL THIS DATA AND ENCODE IT INTO A FROMAT THAT CAN BE SENT VIA NETWORK
    */
    public String packData()
    {
        JSONObject jo=new JSONObject();
        StringBuffer packedData=new StringBuffer();
        try
        {
            jo.put("Name",name);
            jo.put("Position",position);
            jo.put("Team",team);
            Boolean firstValue=true;
            Iterator it=jo.keys();
            do {
                String key=it.next().toString();
                String value=jo.get(key).toString();
                if(firstValue)
                {
                    firstValue=false;
                }else
                {
                    packedData.append("&");
                }
                packedData.append(URLEncoder.encode(key,"UTF-8"));
                packedData.append("=");
                packedData.append(URLEncoder.encode(value,"UTF-8"));
            }while (it.hasNext());
            return packedData.toString();
        } catch (JSONException e) {
            e.printStackTrace();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return null;
        }
}

Classe de l'expéditeur:

package com.tutorials.hp.mysqlinsert;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.widget.EditText;
import android.widget.Toast;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
/**
 * Created by Oclemmy on 3/31/2016 for ProgrammingWizards Channel and Camposha.com.
 * 1.SEND DATA FROM EDITTEXT OVER THE NETWORK
 * 2.DO IT IN BACKGROUND THREAD
 * 3.READ RESPONSE FROM A SERVER
 */
public class Sender extends AsyncTask<Void,Void,String> {
    Context c;
    String urlAddress;
    EditText nameTxt,posTxt,teamTxt;
    String name,pos,team;
    ProgressDialog pd;
    /*
            1.OUR CONSTRUCTOR
    2.RECEIVE CONTEXT,URL ADDRESS AND EDITTEXTS FROM OUR MAINACTIVITY
    */
    public Sender(Context c, String urlAddress,EditText...editTexts) {
        this.c = c;
        this.urlAddress = urlAddress;
        //INPUT EDITTEXTS
        this.nameTxt=editTexts[0];
        this.posTxt=editTexts[1];
        this.teamTxt=editTexts[2];
        //GET TEXTS FROM EDITEXTS
        name=nameTxt.getText().toString();
        pos=posTxt.getText().toString();
        team=teamTxt.getText().toString();
    }
    /*
   1.SHOW PROGRESS DIALOG WHILE DOWNLOADING DATA
    */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pd=new ProgressDialog(c);
        pd.setTitle("Send");
        pd.setMessage("Sending..Please wait");
        pd.show();
    }
    /*
    1.WHERE WE SEND DATA TO NETWORK
    2.RETURNS FOR US A STRING
     */
    @Override
    protected String doInBackground(Void... params) {
        return this.send();
    }
    /*
  1. CALLED WHEN JOB IS OVER
  2. WE DISMISS OUR PD
  3.RECEIVE A STRING FROM DOINBACKGROUND
   */
    @Override
    protected void onPostExecute(String response) {
        super.onPostExecute(response);
        pd.dismiss();
        if(response != null)
        {
            //SUCCESS
            Toast.makeText(c,response,Toast.LENGTH_LONG).show();
            nameTxt.setText("");
            posTxt.setText("");
            teamTxt.setText("");
        }else
        {
            //NO SUCCESS
            Toast.makeText(c,"Unsuccessful "+response,Toast.LENGTH_LONG).show();
        }
    }
/*
SEND DATA OVER THE NETWORK
RECEIVE AND RETURN A RESPONSE
 */
    private String send()
    {
        //CONNECT
        HttpURLConnection con=Connector.connect(urlAddress);
        if(con==null)
        {
            return null;
        }
        try
        {
            OutputStream os=con.getOutputStream();
            //WRITE
            BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(os,"UTF-8"));
            bw.write(new DataPackager(name,pos,team).packData());
            bw.flush();
            //RELEASE RES
            bw.close();
            os.close();
            //HAS IT BEEN SUCCESSFUL?
            int responseCode=con.getResponseCode();
            if(responseCode==con.HTTP_OK)
            {
                //GET EXACT RESPONSE
                BufferedReader br=new BufferedReader(new InputStreamReader(con.getInputStream()));
                StringBuffer response=new StringBuffer();
                String line;
                //READ LINE BY LINE
                while ((line=br.readLine()) != null)
                {
                    response.append(line);
                }
                //RELEASE RES
                br.close();
                return response.toString();
            }else
            {
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }
}

Activité principale:

package com.tutorials.hp.mysqlinsert;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
/*
1.OUR LAUNCHER ACTIVITY
2.INITIALIZE SOME UI STUFF
3.WE START SENDER ON BUTTON CLICK
 */
public class MainActivity extends AppCompatActivity {
    String urlAddress="http://10.0.2.2/android/poster.php";
    EditText nameTxt,posTxt,teamTxt;
    Button saveBtn;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        //INITIALIZE UI FIELDS
        nameTxt= (EditText) findViewById(R.id.nameEditTxt);
        posTxt= (EditText) findViewById(R.id.posEditTxt);
        teamTxt= (EditText) findViewById(R.id.teamEditTxt);
        saveBtn= (Button) findViewById(R.id.saveBtn);
        saveBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //START ASYNC TASK
                Sender s=new Sender(MainActivity.this,urlAddress,nameTxt,posTxt,teamTxt);
                s.execute();
            }
        });
    }
}

ContentMain.xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.tutorials.hp.mysqlinsert.MainActivity"
    tools:showIn="@layout/activity_main">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!" />
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="match_parent"
        android:layout_marginTop="?attr/actionBarSize"
        android:orientation="vertical"
        android:paddingLeft="15dp"
        android:paddingRight="15dp"
        android:paddingTop="50dp">
        <android.support.design.widget.TextInputLayout
            android:id="@+id/nameLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">
            <EditText
                android:id="@+id/nameEditTxt"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:singleLine="true"
                android:hint= "Name" />
        </android.support.design.widget.TextInputLayout>
        <android.support.design.widget.TextInputLayout
            android:id="@+id/teamLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">
            <EditText
                android:id="@+id/teamEditTxt"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="Description" />
        </android.support.design.widget.TextInputLayout>
        <android.support.design.widget.TextInputLayout
            android:id="@+id/posLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">
            <EditText
                android:id="@+id/posEditTxt"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="Position" />
            <!--android:inputType="textPassword"-->
        </android.support.design.widget.TextInputLayout>
        <Button android:id="@+id/saveBtn"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text="Save"
            android:clickable="true"
            android:background="@color/colorAccent"
            android:layout_marginTop="40dp"
            android:textColor="@android:color/white"/>
    </LinearLayout>
</RelativeLayout>

Méthode pour publier des données en tant que requête HTTP,

public static InputStream callPostService(String Url,
        List<NameValuePair> data) {
    HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost(Url);
    try {
        httppost.setEntity(new UrlEncodedFormEntity(data));
        HttpResponse response = httpclient.execute(httppost);
        HttpEntity entity = response.getEntity();
        return entity.getContent();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return null;
}

Vous pouvez POSTER une requête HttpRequest à l'aide de la classe WebServer et suivre la réponse dans son interface d'écoute.

WebServer server=new WebServer(getApplicationContext());

server.setOnServerStatusListner(new WebServer.OnServerStatusListner() {
    @Override
    public void onServerResponded(String responce) {

    }

    @Override
    public void onServerRevoked() {

    }
});

Créez maintenant un DataRack pour lier vos données

List<DataRack> racks=new ArrayList<DataRack>();
racks.add(new DataRack("name","Simon"));
racks.add(new DataRack("age","40"));
racks.add(new DataRack("location","Canada"));

Maintenant, envoyez simplement la demande POST avec ce rack

server.connectWithPOST(MainActivity.this,"http://sangeethnandakumar.esy.es/PROJECTS/PUBLIC_SERVICE/posttest.php",racks);

Vous devez inclure ma bibliothèque pour cela. Documentations ici

Dans les nouvelles versions d'Android, vous devez placer toutes les demandes d'E / S Web dans un nouveau thread. AsyncTask fonctionne mieux pour les petites demandes.