ExternalDelayFetcher.java

package org.tyszecki.rozkladpkp;

import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.util.HashMap;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.os.AsyncTask;
import android.text.TextUtils;
import android.text.format.Time;

public class ExternalDelayFetcher {
	private static HashMap<String, Integer> delays = new HashMap<String, Integer>();
	private static Time lastUpdate = null; 
	
	public static interface ExternalDelayFetcherCallback{
		void ready(HashMap<String, Integer> delays, boolean cached);
	}
	
	static boolean isUpToDate()
	{
		if(lastUpdate == null)
		{
			lastUpdate = new Time();
			lastUpdate.setToNow();
		}
		//Nie aktualizujmy za często.
		long umi = lastUpdate.toMillis(false);
		
		Time current = new Time();
		current.setToNow();
		long nmi = current.toMillis(false);
		
		return !(delays.isEmpty() || nmi-umi < 1000*60*3);
	}
	
	static HashMap<String, Integer> getDelays()
	{
		return delays;
	}
	
	static void requestUpdate(final ExternalDelayFetcherCallback callback)
	{
		class DealyTask extends AsyncTask<Void, Void, Void>{
			@Override
			protected Void doInBackground(Void... arg0) {

				//Prosty skrypt w pythonie parsuje stronę PR i wysyła mi wyniki.
				//To lepsze niż parsowanie bezpośrednio w aplikacji:
				//- W Pythonie można to napisać łatwiej,
				//- Jeśli PR coś zmienią w formacie danych, wystarczy zmiana skryptu żeby działała ta aplikacja
				//- Mogę dodawać do skryptu dane o opóźnieniach z innych źródeł
				String url  = "http://opoznienia.appspot.com";


				DefaultHttpClient client = new DefaultHttpClient();
				HttpGet request = new HttpGet(url);
				request.addHeader("Content-Type", "application/x-www-form-urlencoded");


				HttpResponse response = null;
				InputStream inputStream = null;
				try {
					response = client.execute(request);

					HttpEntity entity = response.getEntity();
					inputStream = entity.getContent();
				} catch (Exception e) {
					e.printStackTrace();
				}



				ByteArrayOutputStream content = new ByteArrayOutputStream();

				byte[] sBuffer = new byte[512];
				// Read response into a buffered stream
				int readBytes = 0;

				try {
					while ((readBytes = inputStream.read(sBuffer)) != -1) {
						content.write(sBuffer, 0, readBytes);
					}
				} catch (Exception e) {
					e.printStackTrace();
				}
				// Return result from buffered stream
				TextUtils.StringSplitter lineSplitter = new TextUtils.SimpleStringSplitter('\n');
				lineSplitter.setString(new String(content.toByteArray()));

				delays.clear();

				for(String s : lineSplitter)
				{
					int col = s.indexOf(':');
					try{
						if(col > -1)
							delays.put(s.substring(0, col), Integer.parseInt(s.substring(col+1)));
					}catch(Exception e)
					{
						return null;
					}
				}
				return null;
			}

			protected void onPostExecute(Void result) {
				callback.ready(delays, false);
			}
		}
		new DealyTask().execute(null,null,null);
	}
}