HttpPost Android: come ottenere il risultato

Question

Ho cercato a lungo di inviare una richiesta HttpPost e recuperare la risposta, ma anche se sono riuscito a stabilire una connessione, non riesco ancora a ottenere il messaggio stringa che viene restituito da la richiesta-risposta

HttpClient httpclient = new DefaultHttpClient(); 
HttpPost httppost = new HttpPost("http://www.myurl.com/app/page.php"); 
// Add your data 
List <NameValuePair> nameValuePairs = new ArrayList <NameValuePair> (5); 
nameValuePairs.add(new BasicNameValuePair("type", "20")); 
nameValuePairs.add(new BasicNameValuePair("mob", "919895865899")); 
nameValuePairs.add(new BasicNameValuePair("pack", "0")); 
nameValuePairs.add(new BasicNameValuePair("exchk", "1")); 

try { 
    httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); 
    Log.d("myapp", "works till here. 2"); 
    try { 
     HttpResponse response = httpclient.execute(httppost); 
     Log.d("myapp", "response " + response.getEntity()); 
    } catch (ClientProtocolException e) { 
     e.printStackTrace(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 
} catch (UnsupportedEncodingException e) { 
    e.printStackTrace(); 
} 

mi dispiace, mi sembra molto ingenuo, perché io sono nuovo a Java. Mi aiuti per favore.

Answer 1

tenta di utilizzare il EntityUtil della risposta:

String responseBody = EntityUtils.toString(response.getEntity()); 

Answer 2

URL url; 
    url = new URL("http://www.url.com/app.php"); 
    URLConnection connection; 
    connection = url.openConnection(); 
    HttpURLConnection httppost = (HttpURLConnection) connection; 
    httppost.setDoInput(true); 
    httppost.setDoOutput(true); 
    httppost.setRequestMethod("POST"); 
    httppost.setRequestProperty("User-Agent", "Tranz-Version-t1.914"); 
    httppost.setRequestProperty("Accept_Language", "en-US"); 
    httppost.setRequestProperty("Content-Type", 
      "application/x-www-form-urlencoded"); 
    DataOutputStream dos = new DataOutputStream(httppost.getOutputStream()); 
    dos.write(b); // bytes[] b of post data 

    String reply; 
    InputStream in = httppost.getInputStream(); 
    StringBuffer sb = new StringBuffer(); 
    try { 
     int chr; 
     while ((chr = in.read()) != -1) { 
      sb.append((char) chr); 
     } 
     reply = sb.toString(); 
    } finally { 
     in.close(); 
    } 

Questo frammento di codice funziona. L'ho preso dopo una ricerca, ma da un codice J2ME.

Answer 3

È possibile chiamare il metodo di eseguire con un ResponseHandler. Ecco un esempio:

ResponseHandler<String> responseHandler = new BasicResponseHandler(); 
String response = httpClient.execute(httppost, responseHandler); 

Answer 4

Prova questo, sembra essere il più compatto. Anche se nel mondo reale, dovresti utilizzare una richiesta asincrona in modo che il dispositivo non si blocchi mentre viene recuperata la pagina richiesta.

http://www.softwarepassion.com/android-series-get-post-and-multipart-post-requests/

Answer 5

Si può fare questo in questo modo

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);  
} 

}

Answer 6

Si dovrebbe provare a utilizzare HttpGet invece di HttpPost. Ho avuto un problema simile e l'ho risolto.