luigi_1 0 Newbie Poster

i was developing an app for android where by clicking on buttons i could control the digital state of an Arduino board. Arduino responses with a xml file created in runtime and, by fetching its contents, i'd like to display the actually state of the pins. Now, i could realize it in fact my app works but i can't handle the fetchXML() method in an AsyncTask instance. Sometimes my UI freezes and i don't want that.

public class HandleXML {

    private String button1 = "button1";
    private String button2 = "button2";
    private String button3 = "button3";
    private String button4 = "button4";
    private String urlString = null;
    private XmlPullParserFactory xmlFactoryObject;

    public volatile boolean parsingComplete = true;

    public HandleXML(String url){
        this.urlString = url;
    }
    public String getbutton1(){
        return button1;
    }
    public String getbutton2(){
        return button2;
    }
    public String getbutton3(){
        return button3;
    }
    public String getbutton4(){
        return button4;
    }

    public void parseXMLAndStoreIt(XmlPullParser myParser) {
        int event;
        String text=null;
        try {
            event = myParser.getEventType();
            while (event != XmlPullParser.END_DOCUMENT) {
                String name=myParser.getName();
                switch (event){
                    case XmlPullParser.START_TAG:
                        break;
                    case XmlPullParser.TEXT:
                        text = myParser.getText();
                        break;

                    case XmlPullParser.END_TAG:
                        if(name.equals("button1")){
                            button1 = text;
                        }
                        else if(name.equals("button2")){
                            button2 = text;// myParser.getText();
                        }
                        else if(name.equals("button3")){
                            button3 = text;//myParser.getText();
                        }
                        else if(name.equals("button4")){
                            button4 = text;//myParser.getText();
                        }
                        else{
                        }
                        break;
                }
                event = myParser.next();

            }
            parsingComplete = false;
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
    public void fetchXML(){
        Thread thread = new Thread(new Runnable(){
            @Override
            public void run() {
                try {
                    URL url = new URL(urlString);
                    HttpURLConnection conn = (HttpURLConnection)
                            url.openConnection();
                    conn.setReadTimeout(1000 /* milliseconds */);
                    conn.setConnectTimeout(1500 /* milliseconds */);
                    conn.setRequestMethod("GET");
                    conn.setDoInput(true);
                    conn.connect();
                    InputStream stream = conn.getInputStream();

                    xmlFactoryObject = XmlPullParserFactory.newInstance();
                    XmlPullParser myparser = xmlFactoryObject.newPullParser();

                    myparser.setFeature(XmlPullParser.FEATURE_PROCESS_NAMESPACES
                            , false);
                    myparser.setInput(stream, null);
                    parseXMLAndStoreIt(myparser);
                    stream.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });

        thread.start();


    }

}

And my main:

public class MainActivity extends ActionBarActivity {

    private String url = "http://192.168.0.254/?domotica";
    private EditText button1,button2,button3,button4;
    private HandleXML obj;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

      /*  if (android.os.Build.VERSION.SDK_INT > 9) {
            StrictMode.ThreadPolicy policy = new     StrictMode.ThreadPolicy.Builder().permitAll().build();
            StrictMode.setThreadPolicy(policy);
        }
      */
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button1 = (EditText)findViewById(R.id.editText1);
        button2 = (EditText)findViewById(R.id.editText2);
        button3 = (EditText)findViewById(R.id.editText3);
        button4 = (EditText)findViewById(R.id.editText4);


        Button dati = (Button) findViewById(R.id.button1);
        Button led1on = (Button) findViewById(R.id.led_1on);
        Button led1off = (Button) findViewById(R.id.led_1off);


        dati.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v){
                //commandArduino("http://192.168.0.254/?b1o");
                //Invio inv = new Invio();
                //inv.execute(url);
                String finalUrl = url;
                obj = new HandleXML(finalUrl);
                obj.fetchXML();
                while(obj.parsingComplete);
                button1.setText(obj.getbutton1());
                button2.setText(obj.getbutton2());
                button3.setText(obj.getbutton3());
                button4.setText(obj.getbutton4());
            }
        });

        led1on.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v){
                //commandArduino("http://192.168.0.254/?b1o");
                Invio inv = new Invio();
                inv.execute("http://192.168.0.254/?b1o");

            }
        });

        led1off.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v){
                //commandArduino("http://192.168.0.254/?b1f");
                Invio inv = new Invio();
                inv.execute("http://192.168.0.254/?b1f");
            }
        });

    }

 private class Invio extends AsyncTask<String,Void,String> {

     @Override
     protected String doInBackground(String... params) {
         int count = params.length;

         for (int i = 0; i < count; i++) {

             try {
                 HttpClient httpclient = new DefaultHttpClient();
                 httpclient.execute(new HttpGet(params[i]));
             } catch (Exception e) {
                 e.printStackTrace();

             }
         }
         return null;
     }
 }


    /*public void open(View view){


    }
*/
    /*public void commandArduino(String urlz) {


    }*/
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}