title: http post not working in android app
body: <p>I am new to android development. I am trying to create a application to scan the QR code string and post the same in web server. I am getting warning in error Method 'post' in 'MainActivity' has incorrect signature and also while clicking the post button I am getting error java.lang.IllegalStateException: Could not find method post(View) in a parent or ancestor Context for android:onClick attribute defined. </p>
  
  <p>How to solve incorrect signature issue in method?</p>
  
  <p>How to pass two variable in method?</p>
  
  <pre><code>public class MainActivity extends AppCompatActivity {
  
  static final String ACTION_SCAN = "com.google.zxing.client.android.SCAN";
  public String contents;
  
  @Override
  public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      //set the main content layout of the Activity
      setContentView(R.layout.activity_main);
  }
  
  //product qr code mode
  public void Scan(View v) {
      try {
          //start the scanning activity from the        com.google.zxing.client.android.SCAN intent
          Intent intent = new Intent(ACTION_SCAN);
          intent.putExtra("SCAN_MODE", "QR_CODE_MODE");
          startActivityForResult(intent, 0);
      } catch (ActivityNotFoundException anfe) {
          //on catch, show the download dialog
          showDialog(MainActivity.this, "No Scanner Found", "Download a   scanner code activity?", "Yes", "No").show();
      }
  }
  
  //alert dialog for downloadDialog
  private static AlertDialog showDialog(final Activity act, CharSequence  title, CharSequence message, CharSequence buttonYes, CharSequence buttonNo) {
          AlertDialog.Builder downloadDialog = new AlertDialog.Builder(act);
      downloadDialog.setTitle(title);
      downloadDialog.setMessage(message);
      downloadDialog.setPositiveButton(buttonYes, new DialogInterface.OnClickListener() {
          public void onClick(DialogInterface dialogInterface, int i) {
              Uri uri = Uri.parse("market://search?q=pname:" + "com.google.zxing.client.android");
              Intent intent = new Intent(Intent.ACTION_VIEW, uri);
              try {
                  act.startActivity(intent);
              } catch (ActivityNotFoundException anfe) {
  
              }
          }
      });
      downloadDialog.setNegativeButton(buttonNo, new DialogInterface.OnClickListener() {
          public void onClick(DialogInterface dialogInterface, int i) {
          }
      });
      return downloadDialog.show();
  }
  
  public void onActivityResult(int requestCode, int resultCode, Intent intent)     {
      if (requestCode == 0) {
          if (resultCode == RESULT_OK) {
              String contents = intent.getStringExtra("SCAN_RESULT");
  
              EditText resultTxt = (EditText) findViewById(R.id.contents);
              resultTxt.setText(contents);
              resultTxt.setVisibility(View.VISIBLE);
          }
  
      }
  
   }
  
  public void post(View view, Intent intent) {
  
                  String contents = intent.getStringExtra("SCAN_RESULT");
                  new JSONtask().execute(contents);
  
              }
  
  
      public class JSONtask extends AsyncTask&lt;String, String, Void&gt; {
  
      @Override
      protected Void doInBackground(String... params) {
  
        try {
  
              // 1. URL
              URL url = new URL("http://192.168.1.10:8080/SRNSmartLab/rest/service/storeNEdata");
              final String contents = params[0];
              // 2. Open connection
              HttpURLConnection conn = (HttpURLConnection) url.openConnection();
  
              // 3. Specify POST method
              conn.setRequestMethod("POST");
  
              // 4. Set the headers
              conn.setRequestProperty("Content-Type", "application/json");
              conn.setDoOutput(true);
  
              // 5. Add JSON data into POST request body
  
  
              //`5.1 Use Jackson object mapper to convert Contnet object into   JSON
              //ObjectMapper mapper = new ObjectMapper();
  
                  // 5.2 Get connection output stream
                 DataOutputStream wr = new DataOutputStream(conn.getOutputStream());
  
              // 5.3 Copy Content "JSON" into
             wr.writeBytes(contents);
  
              // 5.4 Send the request
              wr.flush();
  
              // 5.5 close
              wr.close();
  
              // 6. Get the response
              int responseCode = conn.getResponseCode();
              System.out.println("\nSending 'POST' request to URL : " + url);
              System.out.println("Response Code : " + responseCode);
  
              BufferedReader in = new BufferedReader(
                      new InputStreamReader(conn.getInputStream()));
              String inputLine;
              StringBuffer response = new StringBuffer();
  
              while ((inputLine = in.readLine()) != null) {
                  response.append(inputLine);
              }
              in.close();
  
              // 7. Print result
              System.out.println(response.toString());
  
          } catch (MalformedURLException e) {
              e.printStackTrace();
          } catch (IOException e) {
              e.printStackTrace();
          }
  
          return null;
      }
  
  }
  </code></pre>
  
  <p>} </p>
  
  <p>Here is layout code.</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;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.lab.smart.smartlabinventry.MainActivity"
      tools:showIn="@layout/activity_main"
      android:background="#143de0"&gt;
  
      &lt;TextView
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="@string/Scan"
          android:id="@+id/textView"
      android:layout_alignParentTop="true"
      android:layout_centerHorizontal="true"
      android:textColor="#faf6f6"
      android:textSize="30sp"/&gt;
  
  &lt;RelativeLayout
      android:layout_width="match_parent"
      android:layout_height="match_parent"&gt;
  
      &lt;Button
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="@string/Scan1"
          android:id="@+id/button"
          android:onClick="Scan"
          android:layout_above="@+id/spinner"
          android:layout_toRightOf="@+id/contents"
          android:layout_toEndOf="@+id/contents" /&gt;
  
      &lt;Spinner
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:id="@+id/spinner"
          android:layout_centerVertical="true"
          android:layout_alignRight="@+id/button2"
          android:layout_alignEnd="@+id/button2" /&gt;
      &lt;EditText
          android:id="@+id/contents"
          android:editable="false"
          android:layout_width="fill_parent"
          android:layout_height="wrap_content"
          android:layout_below="@id/spinner"
          android:textColor="#fdf9f9"
          android:layout_marginTop="15dp"
          android:visibility="gone"
          /&gt;
  
      &lt;Button
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:text="@string/upload"
          android:id="@+id/button2"
          android:onClick="post"
          android:layout_alignTop="@+id/button"
          android:layout_alignParentRight="true"
          android:layout_alignParentEnd="true" /&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p></p>