org/sonews/daemon/command/HelpCommand.java
author cli
Tue Apr 27 21:51:12 2010 +0200 (2010-04-27)
changeset 26 407c428adb5b
parent 20 6ae5e4f8329b
permissions -rw-r--r--
Introduce more advanced help system (#565).
     1 /*
     2  *   SONEWS News Server
     3  *   see AUTHORS for the list of contributors
     4  *
     5  *   This program is free software: you can redistribute it and/or modify
     6  *   it under the terms of the GNU General Public License as published by
     7  *   the Free Software Foundation, either version 3 of the License, or
     8  *   (at your option) any later version.
     9  *
    10  *   This program is distributed in the hope that it will be useful,
    11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13  *   GNU General Public License for more details.
    14  *
    15  *   You should have received a copy of the GNU General Public License
    16  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17  */
    18 
    19 package org.sonews.daemon.command;
    20 
    21 import java.io.IOException;
    22 import java.util.Set;
    23 import org.sonews.daemon.CommandSelector;
    24 import org.sonews.daemon.NNTPConnection;
    25 import org.sonews.util.io.Resource;
    26 
    27 /**
    28  * This command provides a short summary of the commands that are
    29  * understood by this implementation of the server. The help text will
    30  * be presented as a multi-line data block following the 100 response
    31  * code (taken from RFC).
    32  * @author Christian Lins
    33  * @since sonews/0.5.0
    34  */
    35 public class HelpCommand implements Command
    36 {
    37 
    38   @Override
    39   public boolean hasFinished()
    40   {
    41     return true;
    42   }
    43 
    44   @Override
    45   public String impliedCapability()
    46   {
    47     return null;
    48   }
    49 
    50   @Override
    51   public boolean isStateful()
    52   {
    53     return true;
    54   }
    55 
    56   @Override
    57   public String[] getSupportedCommandStrings()
    58   {
    59     return new String[]{"HELP"};
    60   }
    61   
    62   @Override
    63   public void processLine(NNTPConnection conn, final String line, byte[] raw)
    64     throws IOException
    65   {
    66     final String[] command = line.split(" ");
    67     conn.println("100 help text follows");
    68 
    69     if(line.length() <= 1)
    70     {
    71       final String[] help = Resource
    72         .getAsString("helpers/helptext", true).split("\n");
    73       for(String hstr : help)
    74       {
    75         conn.println(hstr);
    76       }
    77 
    78       Set<String> commandNames = CommandSelector.getCommandNames();
    79       for(String cmdName : commandNames)
    80       {
    81         conn.println(cmdName);
    82       }
    83     }
    84     else
    85     {
    86       Command cmd = CommandSelector.getInstance().get(command[1]);
    87       if(cmd instanceof HelpfulCommand)
    88       {
    89         conn.println(((HelpfulCommand)cmd).getHelpString());
    90       }
    91       else
    92       {
    93         conn.println("No further help information available.");
    94       }
    95     }
    96     
    97     conn.println(".");
    98   }
    99   
   100 }