Invio di dati POST in Android

I'm experienced with PHP, JavaScript and a lot of other scripting languages, but I don't have a lot of experience with Java or Android.

Sto cercando un modo per inviare dati POST a uno script PHP e visualizzare il risultato.

* Risposta aggiornata che funziona su Android 6.0+. Grazie a @Rohit Suthar , @Tamis Bolvari e @sudhiskr per i commenti. *

    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());
            }
        }
    }

Riferimenti:

• https://developer.android.com/reference/java/net/HttpURLConnection.html
• Come aggiungere parametri a HttpURLConnection usando POST usando NameValuePair

Risposta precedente

Nota: questa soluzione è obsoleta. Funziona solo su dispositivi Android fino alla 5.1. Android 6.0 e versioni successive non includono il client http Apache utilizzato in questa risposta.

Il client HTTP di Apache Commons è la strada da percorrere. È già incluso in Android. Ecco un semplice esempio di come eseguire HTTP Post utilizzandolo.

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
    }
} 

per Android => 5

Le classi org.apache.http e la classe AndroidHttpClient sono state deprecate in Android 5.1 . Queste classi non vengono più gestite e dovresti migrare qualsiasi codice dell'app usando queste API su classi URLConnection il prima possibile.

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

Ho pensato di condividere il mio codice usando 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();
    }

inoltre puoi pubblicare il metodo:

conn.setRequestMethod("POST");

Aggiornamento 21/02/2016

per la richiesta di post con json , vedi questo esempio:

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;
    }
}

AGGIORNAMENTO 24/08/2016

Usa alcune delle migliori librerie, come:

• Ammodernamento
• raffica

perché :

• Evita HttpUrlConnection e HttpClient

A livelli API inferiori (principalmente su Gingerbread e Froyo), HttpUrlConnection e HttpClient sono lungi dall'essere perfetti

• Ed evitare anche AsyncTask
• Sono molto più veloci
• Esse memorizzano nella cache tutto

Dall'introduzione di Honeycomb (API 11), è stato obbligatorio eseguire operazioni di rete su un thread separato, diverso dal thread principale

In questo modo possiamo inviare dati con il metodo post HTTP e ottenere risultati

     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);     
    }
}

Questo è un esempio di come PUBBLICARE i dati multiparte SENZA utilizzare librerie Apache esterne:

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);
}

alla risposta @primpop aggiungerei come convertire la risposta in una stringa:

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);
}

Ecco un esempio di convertStramToString .

Meglio usare Apache Commons HttpClient, che è già incluso anche in Android. Dai un'occhiata allo sviluppatore Android: Riepilogo pacchetto client HTTP Apache per informazioni generali su API.

Puoi usarlo per inviare una richiesta POST HTTP a un URL. Puoi facilmente inviare una richiesta e ottenere una risposta. Lo uso sempre. Lavoro bene con me.

  ///////////////////// 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();
                               }

È inoltre necessario aggiungere il seguente file Jar in libs folde

android-async-http-1.3.1.jar

Finalmente modifica il tuo build.gradle

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

}

Nell'ultimo Ricostruisci il tuo progetto.

Usa la okHttplibreria open source di Square. okHttpfunziona da Android 2.3 e versioni successive e ha una licenza Apache 2.0 su GitHub .

L'invio di dati POST è semplice come l'aggiunta di quanto segue in un 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();

okHttpha anche uno spazio dei nomi su Maven, quindi aggiungerlo al progetto Android Studio è semplice. Aggiungicompile 'com.squareup.okhttp3:okhttp:3.11.0' a build.gradle della tua app.

Codice completo

Aggiungi quanto segue alla tua attività:

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);
    }
}

E chiamalo usando:

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

Per me lavora dopo:

 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;
    }

È possibile utilizzare URLConnectioncon , (per l'invio di dati) e (per la ricezione). Sun ha un esempio proprio per questo .setDoOutput(true)getOutputStream() getInputStream()

Se si desidera solo aggiungere dati all'URL È possibile farlo utilizzando HttpUrlConnection poiché HttpClient è ora obsoleto. Un modo migliore sarebbe usare una libreria come-

Volley Retrofit

Possiamo pubblicare dati nello script php e recuperare il risultato e visualizzarli utilizzando questo codice eseguito tramite 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();}


        }

    }

}

Ma usare librerie come volley o retrofit è un'opzione molto migliore perché la classe Asynctask e HttpurlConnection è più lenta rispetto alle librerie. Anche la libreria prenderà tutto ed è anche più veloce.

Ho trovato questo utile esempio con questo video tutorial.

Classe connettore:

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 mittente:

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;
    }
}

Attività 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>

Metodo per pubblicare dati come richiesta 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;
}

È possibile inviare un HttpRequest utilizzando la classe WebServer e tenere traccia della risposta nell'interfaccia del listener.

WebServer server=new WebServer(getApplicationContext());

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

    }

    @Override
    public void onServerRevoked() {

    }
});

Ora crea un DataRack per associare i tuoi dati

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

Ora invia semplicemente la richiesta POST con quel rack

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

Devi includere la mia biblioteca per questo. Documentazioni qui

Nelle versioni più recenti di Android devi inserire tutte le richieste I / O Web in un nuovo thread. AsyncTask funziona meglio per piccole richieste.