Sending POST data in Android

Question

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.

I'm looking for a way to send POST data to a PHP script and display the result.

Answer 1

Note (Oct 2020): AsyncTask used in the following answer has been deprecated in Android API level 30. Please refer to Official documentation or this blog post for a more updated example

Updated (June 2017) Answer which works on Android 6.0+. Thanks to @Rohit Suthar, @Tamis Bolvari and @sudhiskr for the comments.

    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());             }         }     } 

References:

• https://developer.android.com/reference/java/net/HttpURLConnection.html
• How to add parameters to HttpURLConnection using POST using NameValuePair

Original Answer (May 2010)

Note: This solution is outdated. It only works on Android devices up to 5.1. Android 6.0 and above do not include the Apache http client used in this answer.

Http Client from Apache Commons is the way to go. It is already included in android. Here's a simple example of how to do HTTP Post using it.

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     } }  

Answer 2

for Android = > 5

The org.apache.http classes and the AndroidHttpClient class have been deprecated in Android 5.1. These classes are no longer being maintained and you should migrate any app code using these APIs to the URLConnection classes as soon as possible.

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

Thought of sharing my code using 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();     } 

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also you can Post method :

conn.setRequestMethod("POST"); 

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Update 21/02/2016

for post request with json , see this example :

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;     } } 

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UPDATE 24/08/2016

Use some best library , such as :

• Retrofit
• Volley

because :

• Avoid HttpUrlConnection and HttpClient

On lower API levels (mostly on Gingerbread and Froyo), HttpUrlConnection and HttpClient are far from being perfect

• And Avoid AsyncTask Too
• They are Much Faster
• They Caches Everything

Since the introduction of Honeycomb (API 11), it's been mandatory to perform network operations on a separate thread, different from the main thread