Android Open Source - robotronic Data Fetch Thread

From Project

Back to project page robotronic.

License

The source code is released under:

Copyright (C) 2011 by Drew Schrauf Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the So...

If you think the Android project robotronic listed in this page is inappropriate, such as containing malicious code/tools or violating the copyright, please email info at java2s dot com, thanks.

Java Source Code

package com.drewschrauf.robotronic.threads;
/*from w w  w.j a v  a 2s  . c  o  m*/
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

import android.os.Handler;
import android.os.Message;

import com.drewschrauf.robotronic.database.DatabaseHandler;
import com.drewschrauf.robotronic.threads.ThreadHandler.CacheMode;

public class DataFetchThread extends RobotronicThread {

  private Handler msgHandler;
  private DatabaseHandler dbHandler;
  private boolean useCache;
  private boolean useFresh;

  /**
   * Creates a new DataFetchThread
   * 
   * @param url
   *            The URL to retrieve data from
   * @param msgHandler
   *            The handler to call back to with retrieved binary
   * @param context
   *            The context of the application using Robotronic
   * @param mode
   *            The cache mode to be used
   * @param doneHandler
   *            A generic handler to be called when the thread is done
   */
  public DataFetchThread(String url, Handler msgHandler,
      DatabaseHandler dbHandler, CacheMode mode, Handler doneHandler,
      RobotronicProperties properties) {
    this.url = url;
    this.msgHandler = msgHandler;
    this.dbHandler = dbHandler;
    this.doneHandler = doneHandler;
    this.properties = properties;

    useCache = mode.equals(CacheMode.CACHE_AND_FRESH)
        || mode.equals(CacheMode.CACHE_ONLY);
    useFresh = mode.equals(CacheMode.CACHE_AND_FRESH)
        || mode.equals(CacheMode.FRESH_ONLY);
  }

  /**
   * Fetches the data from the database if it's available then from the
   * network
   */
  public void run() {
    if (isStopping)
      return;

    URL fetchUrl;
    try {
      fetchUrl = new URL(url);
    } catch (final MalformedURLException e) {
      Message msg = Message.obtain();
      msg.what = ThreadHandler.ERROR_URL;
      msg.obj = e;
      msgHandler.sendMessage(msg);
      done();
      return;
    }

    // load items from database if available
    if (useCache) {
      String data = dbHandler.getData(url);
      if (data != null) {
        Message msg = Message.obtain();
        msg.what = ThreadHandler.DATA_CACHE;
        msg.obj = data;
        msgHandler.sendMessage(msg);
      }
    }

    if (isStopping)
      return;

    // load items from URL
    String result;
    try {
      if (useFresh) {
        URLConnection connection = fetchUrl.openConnection();
        if (properties.getDataAcceptType() != null) {
          connection.addRequestProperty("Accept",
              properties.getDataAcceptType());
        }
        BufferedReader in = new BufferedReader(new InputStreamReader(
            connection.getInputStream()));

        StringBuilder resultBuilder = new StringBuilder();
        String inputLine = null;
        while ((inputLine = in.readLine()) != null) {
          resultBuilder.append(inputLine);
        }
        in.close();
        result = resultBuilder.toString();

        if (useCache) {
          dbHandler.addData(url, result);
        }

        Message msg = Message.obtain();
        msg.what = ThreadHandler.DATA_FRESH;
        msg.obj = result;
        msgHandler.sendMessage(msg);
      }
    } catch (IOException ioe) {
      Message msg = Message.obtain();
      msg.what = ThreadHandler.ERROR_IO;
      msg.obj = ioe;
      msgHandler.sendMessage(msg);
      done();
      return;
    }
    done();
  }
}

Java Source Code List