package com.hmkcode.android; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import org.apache.http.HttpResponse; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpPost; import org.apache.http.entity.StringEntity; import org.apache.http.impl.client.DefaultHttpClient; import org.json.JSONObject; import android.net.ConnectivityManager; import android.net.NetworkInfo; import android.os.AsyncTask; import android.os.Bundle; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; import android.widget.Toast; import android.app.Activity; import com.hmkcode.android.vo.Person; public class MainActivity extends Activity implements OnClickListener { TextView tvIsConnected; EditText etName,etCountry,etTwitter; Button btnPost; Person person; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // get reference to the views tvIsConnected = (TextView) findViewById(R.id.tvIsConnected); etName = (EditText) findViewById(R.id.etName); etCountry = (EditText) findViewById(R.id.etCountry); etTwitter = (EditText) findViewById(R.id.etTwitter); btnPost = (Button) findViewById(R.id.btnPost); // check if you are connected or not if(isConnected()){ tvIsConnected.setBackgroundColor(0xFF00CC00); tvIsConnected.setText("You are conncted"); } else{ tvIsConnected.setText("You are NOT conncted"); } // add click listener to Button "POST" btnPost.setOnClickListener(this); } public static String POST(String url, Person person){ InputStream inputStream = null; String result = ""; try { // 1. create HttpClient HttpClient httpclient = new DefaultHttpClient(); // 2. make POST request to the given URL HttpPost httpPost = new HttpPost(url); String json = ""; // 3. build jsonObject JSONObject jsonObject = new JSONObject(); jsonObject.accumulate("name", person.getName()); jsonObject.accumulate("country", person.getCountry()); jsonObject.accumulate("twitter", person.getTwitter()); // 4. convert JSONObject to JSON to String json = jsonObject.toString(); // ** Alternative way to convert Person object to JSON string usin Jackson Lib // ObjectMapper mapper = new ObjectMapper(); // json = mapper.writeValueAsString(person); // 5. set json to StringEntity StringEntity se = new StringEntity(json); // 6. set httpPost Entity httpPost.setEntity(se); // 7. Set some headers to inform server about the type of the content httpPost.setHeader("Accept", "application/json"); httpPost.setHeader("Content-type", "application/json"); // 8. Execute POST request to the given URL HttpResponse httpResponse = httpclient.execute(httpPost); // 9. receive response as inputStream inputStream = httpResponse.getEntity().getContent(); // 10. convert inputstream to string if(inputStream != null) result = convertInputStreamToString(inputStream); else result = "Did not work!"; } catch (Exception e) { Log.d("InputStream", e.getLocalizedMessage()); } // 11. return result return result; } @Override public void onClick(View view) { switch(view.getId()){ case R.id.btnPost: if(!validate()) Toast.makeText(getBaseContext(), "Enter some data!", Toast.LENGTH_LONG).show(); // call AsynTask to perform network operation on separate thread new HttpAsyncTask().execute("http://hmkcode.appspot.com/jsonservlet"); break; } } public boolean isConnected(){ ConnectivityManager connMgr = (ConnectivityManager) getSystemService(Activity.CONNECTIVITY_SERVICE); NetworkInfo networkInfo = connMgr.getActiveNetworkInfo(); if (networkInfo != null && networkInfo.isConnected()) return true; else return false; } private class HttpAsyncTask extends AsyncTask<String, Void, String> { @Override protected String doInBackground(String... urls) { person = new Person(); person.setName(etName.getText().toString()); person.setCountry(etCountry.getText().toString()); person.setTwitter(etTwitter.getText().toString()); return POST(urls[0],person); } // onPostExecute displays the results of the AsyncTask. @Override protected void onPostExecute(String result) { Toast.makeText(getBaseContext(), "Data Sent!", Toast.LENGTH_LONG).show(); } } private boolean validate(){ if(etName.getText().toString().trim().equals("")) return false; else if(etCountry.getText().toString().trim().equals("")) return false; else if(etTwitter.getText().toString().trim().equals("")) return false; else return true; } private static String convertInputStreamToString(InputStream inputStream) throws IOException{ BufferedReader bufferedReader = new BufferedReader( new InputStreamReader(inputStream)); String line = ""; String result = ""; while((line = bufferedReader.readLine()) != null) result += line; inputStream.close(); return result; } }