HTTP GET

gistfile1.txt

package com.runningbus.get;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.HttpURLConnection;
import java.net.URL;

import org.json.JSONException;
import org.json.JSONObject;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;

public class MainActivity extends ActionBarActivity {

	private GoogleMap mMap;
	private TextView lat, lng;
	private ConnectivityManager connMgr;
	private NetworkInfo networkInfo;
	private JSONObject jObject;
	private double latitude, longtitude;
	private String dataSet;
    private static final String GPS = "http://protected-brushlands-3658.herokuapp.com/locations.json";
    private static final String DEBUG_TAG = "HttpExample";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initializeVariables();
        initializeMap();
        initializeMapUtils();
        mMap.setMyLocationEnabled(true);
   
    	if(networkInfo != null && networkInfo.isConnected())
    		new getData().execute(GPS);
    	
        else
            Toast.makeText(getApplicationContext(), "Please connect to the Internet", Toast.LENGTH_LONG).show();
    }
    

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.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();
		if (id == R.id.action_settings) {
			return true;
		}
		return super.onOptionsItemSelected(item);
	}

	@Override
    protected void onResume() {
        super.onResume();
        initializeMap();
    }
    
    private void initializeMapUtils() {
    	// Enable / Disable zooming controls
        mMap.getUiSettings().setZoomControlsEnabled(true);
        // Enable / Disable Compass icon
        mMap.getUiSettings().setCompassEnabled(true);
        // Enable / Disable Rotate gesture
        mMap.getUiSettings().setRotateGesturesEnabled(true);
        // Enable / Disable zooming functionality
        mMap.getUiSettings().setZoomGesturesEnabled(true);
        
    }
    
    private void initializeMap() {
        
    	if (mMap != null) 
            return;
        mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
    }
    
    private void initializeVariables() {
    	lat = (TextView) findViewById(R.id.tvLatitude);
        lng = (TextView) findViewById(R.id.tvLongtitude);
        
        connMgr = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        networkInfo = connMgr.getActiveNetworkInfo();
    }
    
    private class getData extends AsyncTask<String, Void, String> {
    	
        @Override
        protected String doInBackground(String... urls) {
            try {
                dataSet = downloadUrl(urls[0]);

            } catch(IOException e) {
                return "Unable to retrieve web page. URL may be invalid";
            }
            return null;
        }

        @Override
        protected void onPostExecute(String s) {
        	super.onPostExecute(s);
        	try {
				jObject = new JSONObject(dataSet);
				latitude = Double.parseDouble(jObject.getString("lat"));
	        	longtitude = Double.parseDouble(jObject.getString("lng"));
			} catch (JSONException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
            mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(latitude, longtitude), 16));
            mMap.addMarker(new MarkerOptions().position(new LatLng(latitude, longtitude)));
            lat.setText("" + latitude);
            lng.setText("" + longtitude);
            
        }
    }

    //Fetches and processes the web page content and passes back a result string.
    private String downloadUrl(String myurl) throws IOException {
        String contentAsString;
        InputStream is = null;
        // Only display the first 500 characters of the retrieved
        // web page content.
        int len = 500;

        try {
            URL url = new URL(myurl);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setReadTimeout(10000 /* milliseconds */);
            conn.setConnectTimeout(15000 /* milliseconds */);
            conn.setRequestMethod("GET");
            conn.setDoInput(true);
            // Starts the query
            conn.connect();
            int response = conn.getResponseCode();
            Log.d(DEBUG_TAG, "The GET response is: " + response);
            is = conn.getInputStream();

            // Convert the InputStream into a string
            contentAsString = readIt(is, len);
            return contentAsString;

            // Makes sure that the InputStream is closed after the app is
            // finished using it.
        } finally {
            if (is != null) {
                is.close();
            }
        }
    }

    // Reads an InputStream and converts it to a String.
    public String readIt(InputStream stream, int len) throws IOException {
        Reader reader = new InputStreamReader(stream, "UTF-8");
        char[] buffer = new char[len];
        reader.read(buffer);
        return new String(buffer);
    }
}