DownloadManager.java :  » UnTagged » tesis-ar » org » mixare » Android Open Source

/*
 * Copyright (C) 2010- Peer internet solutions
 * 
 * This file is part of mixare.
 * 
 * This program is free software: you can redistribute it and/or modify it 
 * under the terms of the GNU General Public License as published by 
 * the Free Software Foundation, either version 3 of the License, or 
 * (at your option) any later version. 
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License 
 * for more details. 
 * 
 * You should have received a copy of the GNU General Public License along with 
 * this program. If not, see <http://www.gnu.org/licenses/>
 */
package org.mixare;

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

import org.json.JSONArray;
import org.json.JSONObject;
import org.mixare.data.Json;

public class DownloadManager implements Runnable {

  private boolean stop    = false;
  private boolean pause   = false;
  private boolean proceed = false;
  
  public static int NOT_STARTED = 0;
  public static int CONNECTING  = 1;
  public static int CONNECTED   = 2;
  public static int PAUSED      = 3;
  public static int STOPPED     = 4;
  
  @SuppressWarnings("unused")
  private int state = NOT_STARTED;

  private int id = 0;
  
  private HashMap<String, DownloadRequest> todoList = new HashMap<String, DownloadRequest>();
  private HashMap<String, DownloadResult>  doneList = new HashMap<String, DownloadResult>();
  
  InputStream is;

  private String currJobId = null;

  MixContext ctx;

  //------------------------------------------------------
  
  public DownloadManager(MixContext ctx) 
  {
    this.ctx = ctx;
  }

  //------------------------------------------------------
  
  public void run() 
  {
    String jobId;
    
    DownloadRequest request;
    DownloadResult  result;

    stop    = false;
    pause   = false;
    proceed = false;
    
    state   = CONNECTING;

    while (!stop) 
    {
      jobId   = null;
      request = null;
      result  = null;

      // Wait for proceed
      
      while (!stop && !pause) 
      {
        synchronized (this) 
        {
          if (todoList.size() > 0) 
          {
            jobId   = getNextReqId();
            request = todoList.get(jobId);
            proceed = true;
          }
        }

        // Do proceed
        if (proceed) 
        {
          state     = CONNECTED;
          currJobId = jobId;
          result    = processRequest(request);

          synchronized (this) 
          {
            todoList.remove(jobId);
            doneList.put(jobId, result);
            
            proceed = false;
          }
        }
        
        state = CONNECTING;

        if (!stop && !pause)
        {
          sleep(100);
        }
      }

      // Do pause
      
      while (!stop && pause) 
      {
        state = PAUSED;
        sleep(100);
      }
      state = CONNECTING;
    }

    // Do stop
    
    state = STOPPED;
  }

  //------------------------------------------------------
  
  private void sleep(long ms) 
  {
    try 
    {
      Thread.sleep(ms);
    } 
    catch (java.lang.InterruptedException ex) 
    {
    }
  }

  //------------------------------------------------------
  
  private String getNextReqId() {
    return todoList.keySet().iterator().next();
  }
  
  //------------------------------------------------------

  private DownloadResult processRequest(DownloadRequest request) 
  {
    DownloadResult result = new DownloadResult();
    
    try {
        is                = ctx.getHttpGETInputStream(request.url);
        String tmp        = ctx.getHttpInputString(is);
        String ss         = ctx.unescapeHTML(tmp, 0);
        
        JSONObject root   = null;
        
        root              = new JSONObject(ss);
        Json layer        = new Json();
        JSONArray results = new JSONArray();
        
        if (root.has("results")) 
        {
          results = root.getJSONArray("results");
          layer.load(results);
        }
        else 
        {
          results = root.getJSONArray("geonames");
          layer.load(results);
        }
        result.obj = layer;

        result.format   = request.format;
        result.error    = false;
        result.errorMsg = null;

      ctx.returnHttpInputStream(is);
      is = null;

    } 
    catch (Exception ex) 
    {
      result.obj          = null;
      result.error        = true;
      result.errorMsg     = ex.getMessage();
      result.errorRequest = request;

      try 
      {
        ctx.returnHttpInputStream(is);
      } 
      catch (Exception ignore) 
      {
      }

      ex.printStackTrace();
    }

    currJobId = null;

    return result;
  }

  //------------------------------------------------------
  
  public synchronized void purgeLists() 
  {
    todoList.clear();
    doneList.clear();
  }

  //------------------------------------------------------
  
  public synchronized String submitJob(DownloadRequest job) 
  {
    String jobId = "ID_" + (id++);
    
    todoList.put(jobId, job);

    return jobId;
  }

  //------------------------------------------------------
  
  public synchronized boolean isReqComplete(String jobId) 
  {
    return doneList.containsKey(jobId);
  }

  public synchronized DownloadResult getReqResult(String jobId) 
  {
    DownloadResult result = doneList.get(jobId);
    doneList.remove(jobId);

    return result;
  }

  //------------------------------------------------------
  
  public String getActiveReqId() 
  {
    return currJobId;
  }
  
  //------------------------------------------------------
  
  public void pause() 
  {
    pause = true;
  }

  //------------------------------------------------------
  
  public void restart() 
  {
    pause = false;
  }

  //------------------------------------------------------
  
  public void stop() 
  {
    stop = true;
  }
}

//------------------------------------------------------
//------------------------------------------------------

class DownloadRequest 
{
  int format;
  String url;
  String params;
}

//------------------------------------------------------
//------------------------------------------------------

class DownloadResult 
{
  int    format;
  Object obj;

  boolean         error;
  String          errorMsg;
  DownloadRequest errorRequest;
}