Initial commit

src/main/java/xyz/lncvrt/setmaxplayers/SetMaxPlayersCommand.java

@@ -0,0 +1,63 @@
+package xyz.lncvrt.setmaxplayers;
+
+import org.bukkit.ChatColor;
+import org.bukkit.command.Command;
+import org.bukkit.command.CommandExecutor;
+import org.bukkit.command.CommandSender;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.Properties;
+
+import static org.bukkit.Bukkit.getServer;
+
+public class SetMaxPlayersCommand implements CommandExecutor {
+    private final SetMaxPlayers plugin;
+
+    public SetMaxPlayersCommand(SetMaxPlayers plugin) {
+        this.plugin = plugin;
+    }
+
+    @Override
+    public boolean onCommand(CommandSender commandSender, Command command, String s, String[] strings) {
+        if (strings.length != 1) {
+            commandSender.sendMessage(ChatColor.RED + "Correct usage: /setmaxplayers <amount>");
+            return true;
+        }
+        int newMaxPlayers;
+        try {
+            newMaxPlayers = Integer.parseInt(strings[0]);
+        } catch (NumberFormatException e) {
+            commandSender.sendMessage(ChatColor.RED + "Failed to parse value! Correct usage: /setmaxplayers <amount>");
+            return true;
+        }
+        plugin.getServer().setMaxPlayers(newMaxPlayers);
+
+        Properties props = new Properties();
+        Path path = Paths.get("server.properties");
+
+        try (var input = Files.newInputStream(path)) {
+            props.load(input);
+        } catch (IOException e) {
+            plugin.getLogger().info(ChatColor.RED + "Failed to load server.properties file");
+            getServer().getPluginManager().disablePlugin(plugin);
+            throw new RuntimeException(e);
+        }
+
+        props.setProperty("max-players", String.valueOf(newMaxPlayers));
+
+        try (var output = new FileOutputStream(path.toFile())) {
+            props.store(output, null);
+        } catch (IOException e) {
+            plugin.getLogger().info(ChatColor.RED + "Failed to write to server.properties file");
+            getServer().getPluginManager().disablePlugin(plugin);
+            throw new RuntimeException(e);
+        }
+
+        commandSender.sendMessage(ChatColor.GREEN + "The server is now capped to %s players!".formatted(newMaxPlayers));
+        return true;
+    }
+}