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.preference.PreferenceManager;
  21 import android.util.Base64;
  22 import android.util.Log;
  23
  24 import com.google.android.gcm.GCMRegistrar;
  25
  26 /*
  27  * Copyright © 2013 Marius Gavrilescu
  28  *
  29  * This file is part of FonBot.
  30  *
  31  * FonBot is free software: you can redistribute it and/or modify
  32  * it under the terms of the GNU General Public License as published by
  33  * the Free Software Foundation, either version 3 of the License, or
  34  * (at your option) any later version.
  35  *
  36  * FonBot is distributed in the hope that it will be useful,
  37  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  38  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  39  * GNU General Public License for more details.
  40  *
  41  * You should have received a copy of the GNU General Public License
  42  * along with FonBot.  If not, see <http://www.gnu.org/licenses/>.
  43  */
  44
  45 /**
  46  * AsyncTask that polls the server for pending commands and executes any commands found.
  47  *
  48  * @author Marius Gavrilescu <marius@ieval.ro>
  49  */
  50 public final class PollServerAsyncTask extends AsyncTask<Void, Void, List<PollServerAsyncTask.Command>> {
  51         /**
  52          * 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
  53          *
  54          * @author Marius Gavrilescu <marius@ieval.ro>
  55          */
  56         final class Command{
  57                 /**
  58                  * The command name
  59                  */
  60                 final String command;//NOPMD no confusion here
  61                 /**
  62                  * The list of command arguments
  63                  */
  64                 final String[] args;
  65                 /**
  66                  * The reply address, excluding the protocol
  67                  */
  68                 final String replyto;
  69
  70                 /**
  71                  * Construct a Command from its three parts
  72                  *
  73                  * @param command the command name
  74                  * @param args the command arguments
  75                  * @param replyto the reply address
  76                  */
  77                 Command(final String command, final String[] args, final String replyto) {//NOPMD array is immutable
  78                         this.command=command;
  79                         this.args=args;
  80                         this.replyto=replyto;
  81                 }
  82         }
  83
  84         /** Context instance */
  85         private final Context context;
  86
  87         /**
  88          * Constructs a PollServerAsyncTask.
  89          *
  90          * @param context Context instance
  91          */
  92         public PollServerAsyncTask(final Context context) {
  93                 this.context=context;
  94         }
  95
  96         @Override
  97         protected List<Command> doInBackground(final @Nullable Void... params) {
  98                 Log.d(getClass().getName(), "Polling server");
  99                 final List<Command> commands=new ArrayList<Command>(10);
 100                 try {
 101                         final URL url=Utils.getServerURL(toNonNull(context),"/get");
 102                         final HttpURLConnection conn=(HttpURLConnection) url.openConnection();
 103                         conn.setRequestProperty("X-ID", GCMRegistrar.getRegistrationId(context));
 104                         final String user=PreferenceManager.getDefaultSharedPreferences(context).getString("username", null);
 105                         final String password=PreferenceManager.getDefaultSharedPreferences(context).getString("password", null);
 106                         if(user == null || password == null)
 107                                 return commands;
 108
 109                         conn.setRequestProperty("Authorization", "Basic "+Base64.encodeToString(
 110                                         (user+':'+password).getBytes(), Base64.NO_WRAP));
 111                         conn.connect();
 112                         Log.d(getClass().getName(), "Server poll got response code "+conn.getResponseCode()+" and message "+conn.getResponseMessage());
 113                         if(conn.getResponseCode()!=200)
 114                                 return commands;
 115
 116                         final JSONArray array;
 117                         {
 118                                 final byte[] buf=new byte[4096*1024];
 119                                 conn.getInputStream().read(buf);
 120                                 array=new JSONArray(new String(buf));
 121                         }
 122
 123                         for(int i=0;i<array.length();i++){
 124                                 final JSONObject object=array.getJSONObject(i);
 125
 126                                 final JSONArray jsonargs=object.getJSONArray("args");
 127                                 final String[] args=new String[jsonargs.length()];
 128                                 for(int j=0;j<args.length;j++)
 129                                         args[j]=jsonargs.getString(j);
 130
 131                                 commands.add(new Command(//NOPMD command changes for each JSON object
 132                                                 toNonNull(object.getString("command")),
 133                                                 args,
 134                                                 toNonNull(object.getString("replyto"))));
 135                         }
 136                 } catch (MalformedURLException e) {
 137                         e.printStackTrace();
 138                 } catch (IOException e) {
 139                         e.printStackTrace();
 140                 } catch (JSONException e) {
 141                         e.printStackTrace();
 142                 }
 143                 if(commands==null)
 144                         throw new AssertionError("commands is null in PollServerAsyncTask#doInBackground");//silence Eclipse bug
 145                 return commands;
 146         }
 147
 148         @Override
 149         protected void onPostExecute(final @Nullable List<Command> commands) {
 150                 if(commands==null)
 151                         return;
 152                 for (Command command : commands) {
 153                         Log.d(getClass().getName(), "Poll got command "+command.command+" with "+((command.args.length==0)?"no args":"args "+Utils.join(
 154                                         " ",toNonNull(command.args))));
 155                         Utils.processCommand(
 156                                         toNonNull(context),
 157                                         toNonNull(command.command),
 158                                         toNonNull(command.args),
 159                                         new Address(toNonNull(Protocol.HTTP), command.replyto));//NOPMD address depends on command
 160                 }
 161         }
 162 }