src/ro/ieval/fonbot/PollServerAsyncTask.java

   1 package ro.ieval.fonbot;
   2
   3 import static ro.ieval.fonbot.Utils.toNonNull;
   4
   5 import java.io.IOException;
   6 import java.net.HttpURLConnection;
   7 import java.net.MalformedURLException;
   8 import java.net.URL;
   9 import java.util.ArrayList;
  10 import java.util.List;
  11
  12 import org.eclipse.jdt.annotation.Nullable;
  13 import org.json.JSONArray;
  14 import org.json.JSONException;
  15 import org.json.JSONObject;
  16
  17 import ro.ieval.fonbot.Address.Protocol;
  18 import android.content.Context;
  19 import android.os.AsyncTask;
  20 import android.util.Log;
  21
  22 /*
  23  * Copyright © 2013 Marius Gavrilescu
  24  *
  25  * This file is part of FonBot.
  26  *
  27  * FonBot is free software: you can redistribute it and/or modify
  28  * it under the terms of the GNU General Public License as published by
  29  * the Free Software Foundation, either version 3 of the License, or
  30  * (at your option) any later version.
  31  *
  32  * FonBot is distributed in the hope that it will be useful,
  33  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  34  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  35  * GNU General Public License for more details.
  36  *
  37  * You should have received a copy of the GNU General Public License
  38  * along with FonBot.  If not, see <http://www.gnu.org/licenses/>.
  39  */
  40
  41 /**
  42  * AsyncTask that polls the server for pending commands and executes any commands found.
  43  *
  44  * @author Marius Gavrilescu <marius@ieval.ro>
  45  */
  46 public final class PollServerAsyncTask extends AsyncTask<Void, Void, List<PollServerAsyncTask.Command>> {
  47         /**
  48          * POJO that represents a command in a basic form: a command name, a list of arguments and a reply address, all of them being strings
  49          *
  50          * @author Marius Gavrilescu <marius@ieval.ro>
  51          */
  52         final class Command{
  53                 /**
  54                  * The command name
  55                  */
  56                 final String command;//NOPMD no confusion here
  57                 /**
  58                  * The list of command arguments
  59                  */
  60                 final String[] args;
  61                 /**
  62                  * The reply address, excluding the protocol
  63                  */
  64                 final String replyto;
  65
  66                 /**
  67                  * Construct a Command from its three parts
  68                  *
  69                  * @param command the command name
  70                  * @param args the command arguments
  71                  * @param replyto the reply address
  72                  */
  73                 Command(final String command, final String[] args, final String replyto) {//NOPMD array is immutable
  74                         this.command=command;
  75                         this.args=args;
  76                         this.replyto=replyto;
  77                 }
  78         }
  79
  80         /** Context instance */
  81         private final Context context;
  82
  83         /**
  84          * Constructs a PollServerAsyncTask.
  85          *
  86          * @param context Context instance
  87          */
  88         public PollServerAsyncTask(final Context context) {
  89                 this.context=context;
  90         }
  91
  92         @Override
  93         protected List<Command> doInBackground(final @Nullable Void... params) {
  94                 Log.d(getClass().getName(), "Polling server");
  95                 final List<Command> commands=new ArrayList<Command>(10);
  96                 try {
  97                         final URL url=Utils.getServerURL(toNonNull(context),"/get");
  98                         final HttpURLConnection conn=(HttpURLConnection) url.openConnection();
  99                         conn.setRequestProperty("X-ID", FonBotApplication.instance.regID);
 100                         conn.connect();
 101                         final byte[] buf=new byte[4096*1024];
 102                         Log.d(getClass().getName(), "Server poll got response code "+conn.getResponseCode()+" and message "+conn.getResponseMessage());
 103                         if(conn.getResponseCode()!=200)
 104                                 return commands;
 105                         conn.getInputStream().read(buf);
 106                         final JSONArray array=new JSONArray(new String(buf));
 107                         final List<String> list=new ArrayList<String>();
 108                         for(int i=0;i<array.length();i++){
 109                                 final JSONObject object=array.getJSONObject(i);
 110
 111                                 for(int j=0;object.has("arg"+j);j++)
 112                                         list.add(object.getString("arg"+j));
 113
 114                                 commands.add(new Command(//NOPMD command changes for each JSON object
 115                                                 toNonNull(object.getString("command")),
 116                                                 toNonNull(list.toArray(new String[list.size()])),
 117                                                 toNonNull(object.getString("replyto"))));
 118                                 list.clear();
 119                         }
 120                 } catch (MalformedURLException e) {
 121                         e.printStackTrace();
 122                 } catch (IOException e) {
 123                         e.printStackTrace();
 124                 } catch (JSONException e) {
 125                         e.printStackTrace();
 126                 }
 127                 if(commands==null)
 128                         throw new AssertionError("commands is null in PollServerAsyncTask#doInBackground");//silence Eclipse bug
 129                 return commands;
 130         }
 131
 132         @Override
 133         protected void onPostExecute(final @Nullable List<Command> commands) {
 134                 if(commands==null)
 135                         return;
 136                 for (Command command : commands) {
 137                         Log.d(getClass().getName(), "Poll got command "+command.command+" with "+((command.args.length==0)?"no args":"args "+Utils.join(
 138                                         " ",toNonNull(command.args))));
 139                         Utils.processCommand(
 140                                         toNonNull(FonBotApplication.instance),
 141                                         toNonNull(command.command),
 142                                         toNonNull(command.args),
 143                                         new Address(toNonNull(Protocol.HTTP), command.replyto));//NOPMD address depends on command
 144                 }
 145         }
 146 }