Added proper update message

src/main/java/us/myles/ViaVersion/ViaVersionPlugin.java

@@ -6,21 +6,29 @@ import io.netty.channel.ChannelHandler;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
 import io.netty.channel.socket.SocketChannel;
+
 import org.bukkit.Bukkit;
+import org.bukkit.configuration.file.FileConfiguration;
+import org.bukkit.configuration.file.YamlConfiguration;
 import org.bukkit.entity.Player;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.Listener;
 import org.bukkit.event.player.PlayerQuitEvent;
 import org.bukkit.inventory.ItemStack;
 import org.bukkit.plugin.java.JavaPlugin;
+
 import us.myles.ViaVersion.api.ViaVersion;
 import us.myles.ViaVersion.api.ViaVersionAPI;
 import us.myles.ViaVersion.armor.ArmorListener;
 import us.myles.ViaVersion.commands.ViaVersionCommand;
 import us.myles.ViaVersion.handlers.ViaVersionInitializer;
 import us.myles.ViaVersion.listeners.CommandBlockListener;
+import us.myles.ViaVersion.update.UpdateListener;
+import us.myles.ViaVersion.update.UpdateUtil;
 import us.myles.ViaVersion.util.ReflectionUtil;
 
+import java.io.File;
+import java.io.IOException;
 import java.lang.reflect.Field;
 import java.util.List;
 import java.util.Map;
@@ -33,6 +41,8 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
 
     private final Map<UUID, ConnectionInfo> portedPlayers = new ConcurrentHashMap<UUID, ConnectionInfo>();
     private boolean debug = false;
+    private FileConfiguration config;
+    private File configFile;
 
     @Override
     public void onEnable() {
@@ -51,6 +61,21 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
             e.printStackTrace();
         }
         
+        this.config = getFileConfiguration();
+        if(!config.contains("checkforupdates")) {
+        	config.set("checkforupdates", true);
+        	try {
+				config.save(configFile);
+			} catch (IOException e1) {
+				this.getLogger().info("Unabled to write config.yml!");
+				e1.printStackTrace();
+			}
+        }
+        if(config.getBoolean("checkforupdates")) {
+        	Bukkit.getPluginManager().registerEvents(new UpdateListener(this), this);
+        	UpdateUtil.sendUpdateMessage(this);
+        }
+
         Bukkit.getPluginManager().registerEvents(new Listener() {
             @EventHandler
             public void onPlayerQuit(PlayerQuitEvent e) {
@@ -127,6 +152,20 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaVersionAPI {
         portedPlayers.remove(clientID);
     }
     
+    private FileConfiguration getFileConfiguration() {
+    	if(!this.getDataFolder().exists())
+    		this.getDataFolder().mkdirs();
+    	this.configFile = new File(this.getDataFolder(), "config.yml");
+    	if(!this.configFile.exists())
+			try {
+				this.configFile.createNewFile();
+			} catch (IOException e) {
+				this.getLogger().info("Unable to create config.yml!");
+				e.printStackTrace();
+			}
+    	return YamlConfiguration.loadConfiguration(this.configFile);
+    }
+
     public static ItemStack getHandItem(final ConnectionInfo info) {
         try {
             return Bukkit.getScheduler().callSyncMethod(getPlugin(ViaVersionPlugin.class), new Callable<ItemStack>() {

src/main/java/us/myles/ViaVersion/update/UpdateListener.java

@@ -0,0 +1,22 @@
+package us.myles.ViaVersion.update;
+
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerJoinEvent;
+import org.bukkit.plugin.Plugin;
+
+public class UpdateListener implements Listener {
+	
+	private Plugin plugin;
+	
+	public UpdateListener(Plugin plugin) {
+		this.plugin = plugin;
+	}
+	
+	@EventHandler
+	public void onJoin(PlayerJoinEvent e) {
+		if(e.getPlayer().hasPermission("viaversion.update"))
+			UpdateUtil.sendUpdateMessage(e.getPlayer().getUniqueId(), plugin);
+	}
+
+}

src/main/java/us/myles/ViaVersion/update/UpdateUtil.java

@@ -0,0 +1,109 @@
+package us.myles.ViaVersion.update;
+
+import org.bukkit.Bukkit;
+import org.bukkit.ChatColor;
+import org.bukkit.entity.Player;
+import org.bukkit.plugin.Plugin;
+import org.bukkit.scheduler.BukkitRunnable;
+
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.UUID;
+
+import us.myles.ViaVersion.api.ViaVersion;
+
+public class UpdateUtil {
+	
+	private final static String URL = "https://api.spiget.org/v1/resources/";
+	private final static int PLUGIN = 19254;
+	
+	public final static String PREFIX = ChatColor.GREEN + "" + ChatColor.BOLD + "[ViaVersion] " + ChatColor.GREEN;
+	
+	public static void sendUpdateMessage(final UUID uuid, final Plugin plugin) {
+		new BukkitRunnable() {
+
+			@Override
+			public void run() {
+				final String message = getUpdateMessage(false);
+				if(message != null) {
+					new BukkitRunnable() {
+
+						@Override
+						public void run() {
+							Player p = Bukkit.getPlayer(uuid);
+							if(p != null)
+								p.sendMessage(PREFIX + message);
+						}
+					}.runTask(plugin);
+				}
+			}
+		}.runTaskAsynchronously(plugin);
+	}
+	
+	public static void sendUpdateMessage(final Plugin plugin) {
+		new BukkitRunnable() {
+
+			@Override
+			public void run() {
+				final String message = getUpdateMessage(true);
+				if(message != null) {
+					new BukkitRunnable() {
+
+						@Override
+						public void run() {
+							Bukkit.getLogger().info(PREFIX + message);
+						}
+					}.runTask(plugin);
+				}
+			}
+		}.runTaskAsynchronously(plugin);
+	}
+	
+	private static String getUpdateMessage(boolean console) {
+		Version current = new Version(ViaVersion.getInstance().getVersion());
+		Version newest = new Version(getNewestVersion());
+		if(current.compareTo(newest) < 0)
+			return "There is a newer version available: " + newest.toString();
+		else if(console) {
+			if(current.compareTo(newest) == 0)
+				return "You are running the newest version: " + current;
+			else
+				return "You are running a newer version than is released!";
+		}
+		return null;			
+	}
+	
+	private static String getNewestVersion()
+	{
+		String result = "";
+		try {
+	        URL url = new URL(URL + PLUGIN);
+	        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
+	        connection.setUseCaches(true);
+	        connection.addRequestProperty("User-Agent", "Mozilla/4.76");
+	        connection.setDoOutput(true);
+	        BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()));
+            String input;
+            String content = "";
+            while ((input = br.readLine()) != null) {
+                content = content + input;
+            }
+            br.close();
+            JsonParser parser = new JsonParser();
+            JsonObject statistics = (JsonObject)parser.parse(content);
+            result = statistics.get("version").getAsString();
+		} catch(MalformedURLException e) {
+			e.printStackTrace();
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+		return result;
+	}
+}

src/main/java/us/myles/ViaVersion/update/Version.java

@@ -0,0 +1,71 @@
+package us.myles.ViaVersion.update;
+
+public class Version implements Comparable<Version>
+{
+    private int[] parts;
+
+    public Version(String value)
+    {
+        if(value == null)
+            throw new IllegalArgumentException("Version can not be null");
+
+        if(value.matches("^[0-9]+(\\.[0-9]+)*$") == false)
+            throw new IllegalArgumentException("Invalid version format");
+
+        String[] split = value.split("\\.");
+        parts = new int[split.length];
+
+        for (int i = 0; i < split.length; i += 1)
+            parts[i] = Integer.parseInt(split[i]);
+    }
+
+    @Override
+    public String toString()
+    {
+        String[] split = new String[parts.length];
+
+        for (int i = 0; i < parts.length; i += 1)
+            split[i] = String.valueOf(parts[i]);
+
+        return String.join(".", split);
+    }
+
+    public static int compare(Version verA, Version verB)
+    {
+        if (verA == verB) return 0;
+        if (verA == null) return -1;
+        if (verB == null) return 1;
+
+        int max = Math.max(verA.parts.length, verB.parts.length);
+
+        for (int i = 0; i < max; i += 1)
+        {
+            int partA = i < verA.parts.length ? verA.parts[i] : 0;
+            int partB = i < verB.parts.length ? verB.parts[i] : 0;
+            if (partA < partB) return -1;
+            if (partA > partB) return 1;
+        }
+
+        return 0;
+    }
+
+    @Override
+    public int compareTo(Version that)
+    {
+        return compare(this, that);
+    }
+
+    public static boolean equals(Version verA, Version verB)
+    {
+        if (verA == verB) return true;
+        if (verA == null) return false;
+        if (verB == null) return false;
+        return compare(verA, verB) == 0;
+    }
+
+    @Override
+    public boolean equals(Object that)
+    {
+        return that instanceof Version && equals(this, (Version)that);
+    }
+}