Add initial version of command structure.

src/main/java/moe/nekojimi/chords/commands/Command.java

@@ -0,0 +1,41 @@
+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package moe.nekojimi.chords.commands;
+
+import java.util.List;
+import moe.nekojimi.chords.Main;
+import net.dv8tion.jda.api.events.message.guild.GuildMessageReceivedEvent;
+
+/**
+ *
+ * @author jimj316
+ */
+public abstract class Command
+{
+
+    protected final Main bot;
+    protected final String keyword;
+    protected String documentation;
+
+    public Command(Main bot, String keyword)
+    {
+        this.bot = bot;
+        this.keyword = keyword;
+    }
+
+    public abstract void call(GuildMessageReceivedEvent event, List<String> arg);
+
+    public String getKeyword()
+    {
+        return keyword;
+    }
+
+    public String getDocumentation()
+    {
+        return documentation;
+    }
+
+}

src/main/java/moe/nekojimi/chords/commands/JoinCommand.java

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+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package moe.nekojimi.chords.commands;
+
+import java.util.List;
+import moe.nekojimi.chords.Main;
+import net.dv8tion.jda.api.entities.Guild;
+import net.dv8tion.jda.api.entities.MessageChannel;
+import net.dv8tion.jda.api.entities.TextChannel;
+import net.dv8tion.jda.api.entities.VoiceChannel;
+import net.dv8tion.jda.api.events.message.guild.GuildMessageReceivedEvent;
+
+public class JoinCommand extends Command
+{
+
+    public JoinCommand(Main bot)
+    {
+        super(bot, "join");
+    }
+
+    @Override
+    public void call(GuildMessageReceivedEvent event, List<String> args)
+    {
+        String arg0 = args.get(0);
+        Guild guild = event.getGuild();
+        boolean isNumber = arg0.matches("\\d+"); // This is a regular expression that ensures the input consists of digits
+        VoiceChannel channel = null;
+        if (isNumber) // The input is an id?
+            channel = guild.getVoiceChannelById(arg0);
+        if (channel == null)                    // Then the input must be a name?
+        {
+            List<VoiceChannel> channels = guild.getVoiceChannelsByName(arg0, true);
+            if (!channels.isEmpty())            // Make sure we found at least one exact match
+                channel = channels.get(0);      // We found a channel! This cannot be null.
+        }
+
+        TextChannel textChannel = event.getChannel();
+        if (channel == null)                    // I have no idea what you want mr user
+        {
+            onUnknownChannel(textChannel, arg0); // Let the user know about our failure
+            return;
+        }
+        bot.connectTo(channel);                     // We found a channel to connect to!
+        onConnecting(channel, textChannel);     // Let the user know, we were successful!
+    }
+
+    /**
+     * Inform user about successful connection.
+     *
+     * @param channel
+     * The voice channel we connected to
+     * @param textChannel
+     * The text channel to send the message in
+     */
+    public void onConnecting(VoiceChannel channel, TextChannel textChannel)
+    {
+        textChannel.sendMessage("Connecting to " + channel.getName()).queue(); // never forget to queue()!
+    }
+
+    /**
+     * The channel to connect to is not known to us.
+     *
+     * @param channel
+     * The message channel (text channel abstraction) to send failure
+     * information to
+     * @param comment
+     * The information of this channel
+     */
+    public void onUnknownChannel(MessageChannel channel, String comment)
+    {
+        channel.sendMessage("Unable to connect to ``" + comment + "``, no such channel!").queue(); // never forget to queue()!
+    }
+
+}

src/main/java/moe/nekojimi/chords/commands/LeaveCommand.java

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+/*
+ * To change this license header, choose License Headers in Project Properties.
+ * To change this template file, choose Tools | Templates
+ * and open the template in the editor.
+ */
+package moe.nekojimi.chords.commands;
+
+import java.util.List;
+import moe.nekojimi.chords.Main;
+import net.dv8tion.jda.api.events.message.guild.GuildMessageReceivedEvent;
+
+public class LeaveCommand extends Command
+{
+
+    public LeaveCommand(Main bot)
+    {
+        super(bot, "leave");
+    }
+
+    @Override
+    public void call(GuildMessageReceivedEvent event, List<String> arg)
+    {
+        if (bot.getCurrentVoiceChannel() != null)
+        {
+            bot.disconnect();
+        }
+    }
+
+}