Update to Minecraft 1.21.8, add checkstyle, fix compilation errors

- Update Paper API: 1.20.1 -> 1.21.4
- Update plugin version: 1.5.5-1.20.1 -> 1.5.5-1.21.8
- Add checkstyle plugin with reasonable rules
- Fix Enchantment.LUCK -> Enchantment.UNBREAKING
- Fix EntityType.FIREWORK -> EntityType.FIREWORK_ROCKET
- Remove unused imports
- Add temp_*/ to .gitignore
- 118 files changed, 1633 insertions(+), 1301 deletions(-)

lovelocity/build.gradle.kts

@@ -1,5 +1,6 @@
 plugins {
     java
+    checkstyle
 }
 
 repositories {
@@ -12,7 +13,7 @@ dependencies {
     compileOnly("com.velocitypowered:velocity-api:3.3.0-SNAPSHOT")
     annotationProcessor("com.velocitypowered:velocity-api:3.3.0-SNAPSHOT")
     implementation("com.google.code.gson:gson:2.10.1")
-    
+
     testImplementation("org.junit.jupiter:junit-jupiter-api:5.10.0")
     testImplementation("org.junit.jupiter:junit-jupiter-engine:5.10.0")
     testRuntimeOnly("org.junit.platform:junit-platform-launcher:1.10.0")
@@ -23,3 +24,17 @@ tasks.jar {
     from(configurations.runtimeClasspath.get().map { if (it.isDirectory) it else zipTree(it) })
     duplicatesStrategy = DuplicatesStrategy.EXCLUDE
 }
+
+checkstyle {
+    toolVersion = "10.12.5"
+    configFile = file("${rootProject.rootDir}/config/checkstyle/checkstyle.xml")
+    isIgnoreFailures = false
+    maxWarnings = 0
+}
+
+tasks.withType<Checkstyle> {
+    reports {
+        xml.required.set(false)
+        html.required.set(true)
+    }
+}

lovelocity/src/main/java/com/loki/lovelocity/LoVelocity.java

@@ -13,52 +13,52 @@ import org.slf4j.Logger;
 import java.nio.file.Path;
 
 @Plugin(
-    id = "lovelocity",
-    name = "LoVelocity",
-    version = "1.5.5",
-    description = "Velocity integration for LoNetwork",
-    authors = {"loki"}
+        id = "lovelocity",
+        name = "LoVelocity",
+        version = "1.5.5",
+        description = "Velocity integration for LoNetwork",
+        authors = {"loki"}
 )
 public class LoVelocity {
-    
+
     private final ProxyServer server;
     private final Logger logger;
     private final Path dataDirectory;
-    
+
     @Inject
     public LoVelocity(ProxyServer server, Logger logger, @DataDirectory Path dataDirectory) {
         this.server = server;
         this.logger = logger;
         this.dataDirectory = dataDirectory;
     }
-    
+
     @Subscribe
     public void onProxyInitialization(ProxyInitializeEvent event) {
         logger.info("LoVelocity loaded!");
         logger.info("Version: 1.5.5");
-        
+
         registerCommands();
     }
-    
+
     private void registerCommands() {
         CommandMeta hubMeta = server.getCommandManager().metaBuilder("hub")
-            .aliases("lobby")
-            .plugin(this)
-            .build();
-        
+                .aliases("lobby")
+                .plugin(this)
+                .build();
+
         server.getCommandManager().register(hubMeta, new HubCommand(this));
-        
+
         logger.info("Commands registered: /hub, /lobby");
     }
-    
+
     public ProxyServer getServer() {
         return server;
     }
-    
+
     public Logger getLogger() {
         return logger;
     }
-    
+
     public Path getDataDirectory() {
         return dataDirectory;
     }

lovelocity/src/main/java/com/loki/lovelocity/commands/HubCommand.java

@@ -12,66 +12,66 @@ import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 
 public class HubCommand implements SimpleCommand {
-    
+
     private final LoVelocity plugin;
     private final List<String> hubServers = List.of("hub", "lobby");
-    
+
     public HubCommand(LoVelocity plugin) {
         this.plugin = plugin;
     }
-    
+
     @Override
     public void execute(Invocation invocation) {
         if (!(invocation.source() instanceof Player player)) {
             invocation.source().sendMessage(Component.text("This command is only for players!", NamedTextColor.RED));
             return;
         }
-        
+
         Optional<RegisteredServer> currentServer = player.getCurrentServer().map(s -> s.getServer());
-        
+
         if (currentServer.isEmpty()) {
             player.sendMessage(Component.text("Failed to determine current server!", NamedTextColor.RED));
             return;
         }
-        
+
         String currentServerName = currentServer.get().getServerInfo().getName().toLowerCase();
-        
+
         if (isHubServer(currentServerName)) {
             player.sendMessage(Component.text("You are already on the hub!", NamedTextColor.YELLOW));
             return;
         }
-        
+
         Optional<RegisteredServer> hubServer = findHubServer();
-        
+
         if (hubServer.isEmpty()) {
             player.sendMessage(Component.text("Hub server not found!", NamedTextColor.RED));
-            plugin.getLogger().warn("Hub server not found! Available servers: " + 
-                plugin.getServer().getAllServers().stream()
-                    .map(s -> s.getServerInfo().getName())
-                    .toList());
+            plugin.getLogger().warn("Hub server not found! Available servers: " +
+                    plugin.getServer().getAllServers().stream()
+                            .map(s -> s.getServerInfo().getName())
+                            .toList());
             return;
         }
-        
+
         player.sendMessage(Component.text("Teleporting to hub...", NamedTextColor.GREEN));
-        
+
         player.createConnectionRequest(hubServer.get()).fireAndForget();
     }
-    
+
     private boolean isHubServer(String serverName) {
         return hubServers.stream().anyMatch(hub -> serverName.contains(hub));
     }
-    
+
     private Optional<RegisteredServer> findHubServer() {
         return plugin.getServer().getAllServers().stream()
-            .filter(server -> isHubServer(server.getServerInfo().getName().toLowerCase()))
-            .findFirst();
+                .filter(server -> isHubServer(server.getServerInfo().getName().toLowerCase()))
+                .findFirst();
     }
-    
+
     @Override
     public CompletableFuture<List<String>> suggestAsync(Invocation invocation) {
         return CompletableFuture.completedFuture(List.of());
     }
-    
+
     @Override
     public boolean hasPermission(Invocation invocation) {
         return invocation.source().hasPermission("lovelocity.hub");