refactor server

2024-01-01 21:51:21 +09:00
parent c55d170292
commit 2f3079faac
90 changed files with 293 additions and 203 deletions
--- a/client/src/main/java/org/kareha/hareka/client/Session.java
+++ b/client/src/main/java/org/kareha/hareka/client/Session.java
@@ -9,6 +9,8 @@ import java.util.concurrent.atomic.AtomicLong;

 import org.kareha.hareka.ManuallyClosable;
 import org.kareha.hareka.annotation.GuardedBy;
+import org.kareha.hareka.annotation.NotFinalForTesting;
+import org.kareha.hareka.annotation.NotPrivateForTesting;
 import org.kareha.hareka.client.mirror.Mirrors;
 import org.kareha.hareka.client.protocol.ServerPacket;
 import org.kareha.hareka.client.protocol.ServerRequestPacket;
@@ -19,7 +21,7 @@ import org.kareha.hareka.protocol.ClientPacketType;
 import org.kareha.hareka.protocol.HandlerTable;
 import org.kareha.hareka.protocol.ProtocolSocket;

-// not final for FakeSession
+@NotFinalForTesting
 public class Session implements ManuallyClosable {

 	private volatile ConnectionSettings.Entry connection;
@@ -37,12 +39,12 @@ public class Session implements ManuallyClosable {
 	private volatile Mirrors mirrors;
 	private final DiceRollTable diceRollTable = new DiceRollTable();

-	// not private for test
+	@NotPrivateForTesting
 	protected Session(final Context context) {
 		this.context = context;
 	}

-	// not private for test
+	@NotPrivateForTesting
 	protected ProtocolSocket<ClientPacketType, Session> newPacketSocket(final Socket socket,
 			final HandlerTable<ClientPacketType, Session> parserTable) {
 		return new ProtocolSocket<ClientPacketType, Session>(socket, parserTable, this) {
@@ -53,7 +55,7 @@ public class Session implements ManuallyClosable {
 		};
 	}

-	// not private for test
+	@NotPrivateForTesting
 	protected void initialize(final Socket socket, final HandlerTable<ClientPacketType, Session> parserTable) {
 		packetSocket = newPacketSocket(socket, parserTable);
 		mirrors = new Mirrors(this);
--- a/server/src/main/java/org/kareha/hareka/server/Context.java
+++ b/server/src/main/java/org/kareha/hareka/server/Context.java
@@ -12,9 +12,6 @@ import org.kareha.hareka.persistent.FastPersistentHashTable;
 import org.kareha.hareka.persistent.PersistentHashTable;
 import org.kareha.hareka.server.entity.Entities;
 import org.kareha.hareka.server.entity.EntityStatic;
-import org.kareha.hareka.server.external.SessionStatic;
-import org.kareha.hareka.server.external.Sessions;
-import org.kareha.hareka.server.external.GameServer;
 import org.kareha.hareka.server.field.FieldStatic;
 import org.kareha.hareka.server.field.Fields;
 import org.kareha.hareka.server.game.CharacterSpawner;
@@ -22,6 +19,9 @@ import org.kareha.hareka.server.game.Clock;
 import org.kareha.hareka.server.game.ItemSpawner;
 import org.kareha.hareka.server.item.Items;
 import org.kareha.hareka.server.net.Server;
+import org.kareha.hareka.server.session.SessionServer;
+import org.kareha.hareka.server.session.SessionStatic;
+import org.kareha.hareka.server.session.Sessions;
 import org.kareha.hareka.server.skill.ActiveSkills;
 import org.kareha.hareka.server.stat.SpeciesTable;
 import org.kareha.hareka.server.user.AccessController;
@@ -97,10 +97,10 @@ public final class Context {
 		characterSpawner = new CharacterSpawner(new File(dataDirectory, "CharacterSpawner.xml"));
 		itemSpawner = new ItemSpawner(new File(dataDirectory, "ItemSpawner.xml"));
 		if (parameters.noTls()) {
-			server = new GameServer(this, parameters.port(), null);
+			server = new SessionServer(this, parameters.port(), null);
 		} else {
 			final var keyStoreFile = new File(dataDirectory.getParent(), ServerConstants.KEY_STORE_FILENAME);
-			server = new GameServer(this, parameters.port(), keyStoreFile);
+			server = new SessionServer(this, parameters.port(), keyStoreFile);
 		}
 	}

--- a/server/src/main/java/org/kareha/hareka/server/Main.java
+++ b/server/src/main/java/org/kareha/hareka/server/Main.java
@@ -9,7 +9,7 @@ import javax.swing.SwingUtilities;

 import org.kareha.hareka.logging.FileLogger;
 import org.kareha.hareka.logging.SimpleLogger;
-import org.kareha.hareka.server.net.ServerException;
+import org.kareha.hareka.server.net.ServerSocketException;
 import org.kareha.hareka.tool.KeyStoreUtil;
 import org.kareha.hareka.tool.LogUtil;
 import org.kareha.hareka.util.FileUtil;
@@ -62,7 +62,7 @@ final class Main {
 		case CONSOLE:
 			try {
 				Starter.INSTANCE.start(parameters);
-			} catch (final IOException | JAXBException | ServerException e) {
+			} catch (final IOException | JAXBException | ServerSocketException e) {
 				logger.log(Level.SEVERE, "", e);
 				return;
 			}
--- a/server/src/main/java/org/kareha/hareka/server/MainFrame.java
+++ b/server/src/main/java/org/kareha/hareka/server/MainFrame.java
@@ -19,7 +19,7 @@ import javax.swing.WindowConstants;

 import org.kareha.hareka.annotation.ConfinedTo;
 import org.kareha.hareka.annotation.Private;
-import org.kareha.hareka.server.net.ServerException;
+import org.kareha.hareka.server.net.ServerSocketException;
 import org.kareha.hareka.ui.swing.LogPanel;

 import jakarta.xml.bind.JAXBException;
@@ -115,7 +115,7 @@ public final class MainFrame extends JFrame {
 		new Thread(() -> {
 			try {
 				Starter.INSTANCE.start(params);
-			} catch (final IOException | JAXBException | ServerException e) {
+			} catch (final IOException | JAXBException | ServerSocketException e) {
 				SwingUtilities.invokeLater(() -> {
 					logger.log(Level.SEVERE, "", e);
 					JOptionPane.showMessageDialog(MainFrame.this, e.getMessage());
--- a/server/src/main/java/org/kareha/hareka/server/Saver.java
+++ b/server/src/main/java/org/kareha/hareka/server/Saver.java
@@ -6,7 +6,8 @@ import java.util.logging.Level;
 import java.util.logging.Logger;

 import org.kareha.hareka.logging.SimpleLogger;
-import org.kareha.hareka.server.net.ServerException;
+import org.kareha.hareka.server.net.IllegalServerStateException;
+import org.kareha.hareka.server.net.ServerSocketException;

 import jakarta.xml.bind.JAXBException;

@@ -52,6 +53,13 @@ public enum Saver {
 		// Stop listening
 		try {
 			context.server().stop();
+		} catch (final IllegalServerStateException e) {
+			if (shutdown) {
+				SimpleLogger.INSTANCE.log("Failed to stop server; Server has already been stopped");
+			} else {
+				logger.warning("Failed to stop server; Server has already been stopped");
+			}
+			return;
 		} catch (final IOException e) {
 			if (shutdown) {
 				SimpleLogger.INSTANCE.log(e);
@@ -109,7 +117,10 @@ public enum Saver {
 		// Start listening
 		try {
 			context.server().start();
-		} catch (final IOException | ServerException e) {
+		} catch (final IllegalServerStateException e) {
+			logger.warning("Failed to start server; Server is already running.");
+			return;
+		} catch (final IOException | ServerSocketException e) {
 			logger.log(Level.SEVERE, "", e);
 			return;
 		}
--- a/server/src/main/java/org/kareha/hareka/server/ServerConstants.java
+++ b/server/src/main/java/org/kareha/hareka/server/ServerConstants.java
@@ -7,9 +7,10 @@ public final class ServerConstants {
 	}

 	public static final String KEY_STORE_FILENAME = "KeyStore";
-	// Using keytool, you must specify minimum 6 character password
-	public static final String KEY_STORE_PASSWORD = "foobar";
-	public static final String KEY_PASSWORD = "foobar";
+	// Using keytool, you must specify minimum 6 character password.
+	// "changeit" is the common default password in Java world.
+	public static final String KEY_STORE_PASSWORD = "changeit";
+	public static final String KEY_PASSWORD = "changeit";
 	public static final int CONNECTION_SIZE = 100;
 	public static final int MAX_CHARACTERS_PER_USER = 4;
 	public static final String DICE_ROLL_HASH_ALGORITHM = "SHA-256";
--- a/server/src/main/java/org/kareha/hareka/server/Starter.java
+++ b/server/src/main/java/org/kareha/hareka/server/Starter.java
@@ -6,7 +6,8 @@ import java.util.logging.Logger;

 import org.kareha.hareka.Constants;
 import org.kareha.hareka.annotation.GuardedBy;
-import org.kareha.hareka.server.net.ServerException;
+import org.kareha.hareka.server.net.IllegalServerStateException;
+import org.kareha.hareka.server.net.ServerSocketException;
 import org.kareha.hareka.util.FileUtil;

 import jakarta.xml.bind.DatatypeConverter;
@@ -23,7 +24,7 @@ public enum Starter {
 	private boolean shutdownHookAdded = false;

 	public synchronized void start(final ServerParameters parameters)
-			throws IOException, JAXBException, ServerException {
+			throws IOException, JAXBException, ServerSocketException {
 		FileUtil.ensureDirectoryExists(parameters.liveDirectory());

 		final var crashedFile = new File(parameters.liveDirectory(), ServerConstants.CRASHED_FILENAME);
@@ -102,7 +103,11 @@ public enum Starter {
 		context.entities().startMotion();

 		// Start listening
-		context.server().start();
+		try {
+			context.server().start();
+		} catch (final IllegalServerStateException e) {
+			logger.warning("Failed to start server; Server is already running.");
+		}
 	}

 }
--- a/server/src/main/java/org/kareha/hareka/server/external/Sessions.java
+++ b/server/src/main/java/org/kareha/hareka/server/external/Sessions.java
@@ -1,52 +0,0 @@
-package org.kareha.hareka.server.external;
-
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.HashSet;
-import java.util.Set;
-import java.util.logging.Logger;
-
-import org.kareha.hareka.annotation.GuardedBy;
-import org.kareha.hareka.annotation.ThreadSafe;
-
-@ThreadSafe
-public final class Sessions {
-
-	private static final Logger logger = Logger.getLogger(Sessions.class.getName());
-
-	@GuardedBy("this")
-	private final Set<Session> sessions = new HashSet<>();
-
-	public synchronized boolean addSession(final Session session) {
-		final var b = sessions.add(session);
-		if (b) {
-			logger.info(session.getStamp() + "Connected");
-		} else {
-			logger.warning(session.getStamp() + "Already connected");
-		}
-		return b;
-	}
-
-	public synchronized boolean removeSession(final Session session) {
-		final var b = sessions.remove(session);
-		if (b) {
-			logger.info(session.getStamp() + "Disconnected");
-		} else {
-			logger.warning(session.getStamp() + "Already disconnected");
-		}
-		return b;
-	}
-
-	public synchronized Collection<Session> getSessions() {
-		if (sessions.isEmpty()) {
-			return Collections.emptyList();
-		}
-		return new ArrayList<>(sessions);
-	}
-
-	public synchronized int sizeOfSessions() {
-		return sessions.size();
-	}
-
-}
--- a/server/src/main/java/org/kareha/hareka/server/game/Player.java
+++ b/server/src/main/java/org/kareha/hareka/server/game/Player.java
@@ -18,7 +18,6 @@ import org.kareha.hareka.server.entity.ChatDriver;
 import org.kareha.hareka.server.entity.ChatEntity;
 import org.kareha.hareka.server.entity.FieldDriver;
 import org.kareha.hareka.server.entity.FieldEntity;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.field.FieldPosition;
 import org.kareha.hareka.server.field.ServerFieldObject;
 import org.kareha.hareka.server.packet.AddActiveSkillPacket;
@@ -43,6 +42,7 @@ import org.kareha.hareka.server.packet.SelfNamePacket;
 import org.kareha.hareka.server.packet.TilesPacket;
 import org.kareha.hareka.server.packet.CooldownPacket;
 import org.kareha.hareka.server.packet.WeightBarPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.server.stat.StatPoints;
 import org.kareha.hareka.server.user.User;

--- a/server/src/main/java/org/kareha/hareka/server/handler/AddDownstairsHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/AddDownstairsHandler.java
@@ -9,8 +9,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.field.ServerField;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class AddDownstairsHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/AddGatePairHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/AddGatePairHandler.java
@@ -8,9 +8,9 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.field.FieldPosition;
 import org.kareha.hareka.server.field.Gate;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class AddGatePairHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/AddUpstairsHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/AddUpstairsHandler.java
@@ -9,8 +9,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.field.ServerField;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;
 import org.kareha.hareka.user.RoleSet;

--- a/server/src/main/java/org/kareha/hareka/server/handler/AutopilotHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/AutopilotHandler.java
@@ -7,7 +7,7 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;

 public final class AutopilotHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/CancelPowHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/CancelPowHandler.java
@@ -8,7 +8,7 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;

 public final class CancelPowHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/CancelTokenHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/CancelTokenHandler.java
@@ -7,8 +7,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.game.TokenReceiver;
+import org.kareha.hareka.server.session.Session;

 public final class CancelTokenHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/ChangeNameHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/ChangeNameHandler.java
@@ -10,8 +10,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.SelfNamePacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.tool.Utf8Util;

 public final class ChangeNameHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/CommandHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/CommandHandler.java
@@ -6,8 +6,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.CommandOutPacket;
+import org.kareha.hareka.server.session.Session;

 public final class CommandHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/ConsumeRoleTokenHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/ConsumeRoleTokenHandler.java
@@ -8,7 +8,7 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;

 public final class ConsumeRoleTokenHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/DefineRoleHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/DefineRoleHandler.java
@@ -9,8 +9,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.RoleListPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.server.user.CustomRole;
 import org.kareha.hareka.server.user.RolesLogRecord;
 import org.kareha.hareka.user.Permission;
--- a/server/src/main/java/org/kareha/hareka/server/handler/DeleteCharacterHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/DeleteCharacterHandler.java
@@ -9,8 +9,8 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.entity.CharacterEntity;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.CharactersPacket;
+import org.kareha.hareka.server.session.Session;

 public final class DeleteCharacterHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/DeleteItemHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/DeleteItemHandler.java
@@ -7,7 +7,7 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;

 public final class DeleteItemHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/DeleteRoleTokenHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/DeleteRoleTokenHandler.java
@@ -6,8 +6,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.RoleTokenListPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class DeleteRoleTokenHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/DiceChoiceHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/DiceChoiceHandler.java
@@ -9,8 +9,8 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.ServerConstants;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.DiceResultPacket;
+import org.kareha.hareka.server.session.Session;

 public final class DiceChoiceHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/DiceTokenHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/DiceTokenHandler.java
@@ -9,8 +9,8 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.ServerConstants;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.RequestDiceChoicePacket;
+import org.kareha.hareka.server.session.Session;

 public final class DiceTokenHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/DrawLineHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/DrawLineHandler.java
@@ -13,8 +13,8 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.ServerConstants;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.RequestPowPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class DrawLineHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/DrawRingHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/DrawRingHandler.java
@@ -14,8 +14,8 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.ServerConstants;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.RequestPowPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class DrawRingHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/DropItemHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/DropItemHandler.java
@@ -7,7 +7,7 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;

 public final class DropItemHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/FillRangeHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/FillRangeHandler.java
@@ -13,8 +13,8 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.ServerConstants;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.RequestPowPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class FillRangeHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/GenerateTerrainHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/GenerateTerrainHandler.java
@@ -12,8 +12,8 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.ServerConstants;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.RequestPowPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class GenerateTerrainHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/GetPlacementRecordHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/GetPlacementRecordHandler.java
@@ -6,8 +6,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.PlacementRecordPacket;
+import org.kareha.hareka.server.session.Session;

 public final class GetPlacementRecordHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/InspectChatEntityHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/InspectChatEntityHandler.java
@@ -11,8 +11,8 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.entity.CharacterEntity;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.InspectionPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;
 import org.kareha.hareka.user.UserId;

--- a/server/src/main/java/org/kareha/hareka/server/handler/InspectFieldEntityHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/InspectFieldEntityHandler.java
@@ -12,8 +12,8 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.entity.CharacterEntity;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.InspectionPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;
 import org.kareha.hareka.user.UserId;

--- a/server/src/main/java/org/kareha/hareka/server/handler/IssueInvitationTokenHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/IssueInvitationTokenHandler.java
@@ -8,8 +8,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.TextPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.server.user.InvitationTokensLogRecord;
 import org.kareha.hareka.user.Permission;

--- a/server/src/main/java/org/kareha/hareka/server/handler/IssueRoleTokenHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/IssueRoleTokenHandler.java
@@ -7,8 +7,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.TextPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 import jakarta.xml.bind.DatatypeConverter;
--- a/server/src/main/java/org/kareha/hareka/server/handler/LocalChatHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/LocalChatHandler.java
@@ -8,7 +8,7 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;

 public final class LocalChatHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/LocaleHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/LocaleHandler.java
@@ -9,7 +9,7 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;

 public final class LocaleHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/LoginCharacterHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/LoginCharacterHandler.java
@@ -10,9 +10,9 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.entity.CharacterEntity;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.field.FieldId;
 import org.kareha.hareka.server.game.Player;
+import org.kareha.hareka.server.session.Session;

 public final class LoginCharacterHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/LoginUserHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/LoginUserHandler.java
@@ -14,13 +14,13 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.game.TokenReceiver;
 import org.kareha.hareka.server.packet.CharactersPacket;
 import org.kareha.hareka.server.packet.MessagePacket;
 import org.kareha.hareka.server.packet.RequestPowPacket;
 import org.kareha.hareka.server.packet.RequestPublicKeyPacket;
 import org.kareha.hareka.server.packet.RequestTokenPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.server.user.InvitationToken;
 import org.kareha.hareka.server.user.InvitationTokensLogRecord;
 import org.kareha.hareka.user.UserId;
--- a/server/src/main/java/org/kareha/hareka/server/handler/LogoutCharacterHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/LogoutCharacterHandler.java
@@ -7,8 +7,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.CharactersPacket;
+import org.kareha.hareka.server.session.Session;

 public final class LogoutCharacterHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/LogoutUserHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/LogoutUserHandler.java
@@ -7,8 +7,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.VersionPacket;
+import org.kareha.hareka.server.session.Session;

 public final class LogoutUserHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/MoveHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/MoveHandler.java
@@ -10,8 +10,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.CooldownPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.server.stat.ExperienceType;
 import org.kareha.hareka.server.stat.ExperienceVariation;

--- a/server/src/main/java/org/kareha/hareka/server/handler/NewCharacterHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/NewCharacterHandler.java
@@ -11,8 +11,8 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.ServerConstants;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.CharactersPacket;
+import org.kareha.hareka.server.session.Session;

 public final class NewCharacterHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/NewFieldHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/NewFieldHandler.java
@@ -11,11 +11,11 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.field.FieldPosition;
 import org.kareha.hareka.server.field.Gate;
 import org.kareha.hareka.server.field.PeriodicBoundary;
 import org.kareha.hareka.server.field.ServerField;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class NewFieldHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/NoPublicKeyHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/NoPublicKeyHandler.java
@@ -8,7 +8,7 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;

 public final class NoPublicKeyHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/PowHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/PowHandler.java
@@ -8,7 +8,7 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;

 public final class PowHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/PrivateChatHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/PrivateChatHandler.java
@@ -9,7 +9,7 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.entity.ChatEntity;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;

 public final class PrivateChatHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/PublicKeyHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/PublicKeyHandler.java
@@ -12,7 +12,7 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;

 public final class PublicKeyHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/RebootHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/RebootHandler.java
@@ -8,7 +8,7 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.Rebooter;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class RebootHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/ReduceToBackgroundTilesHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/ReduceToBackgroundTilesHandler.java
@@ -7,7 +7,7 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class ReduceToBackgroundTilesHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/RemoveOrphansHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/RemoveOrphansHandler.java
@@ -6,7 +6,7 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class RemoveOrphansHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/RemoveSpecialTileHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/RemoveSpecialTileHandler.java
@@ -12,8 +12,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.field.ServerField;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class RemoveSpecialTileHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/RequestEchoHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/RequestEchoHandler.java
@@ -6,8 +6,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.EchoPacket;
+import org.kareha.hareka.server.session.Session;

 public final class RequestEchoHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/RequestMyRolesHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/RequestMyRolesHandler.java
@@ -6,8 +6,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.MyRolesPacket;
+import org.kareha.hareka.server.session.Session;

 public final class RequestMyRolesHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/RequestPublicKeyHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/RequestPublicKeyHandler.java
@@ -10,9 +10,9 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.NoPublicKeyPacket;
 import org.kareha.hareka.server.packet.PublicKeyPacket;
+import org.kareha.hareka.server.session.Session;

 import jakarta.xml.bind.JAXBException;

--- a/server/src/main/java/org/kareha/hareka/server/handler/RequestRegionListHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/RequestRegionListHandler.java
@@ -7,8 +7,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.RegionListPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class RequestRegionListHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/RequestRoleListHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/RequestRoleListHandler.java
@@ -6,8 +6,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.RoleListPacket;
+import org.kareha.hareka.server.session.Session;

 public final class RequestRoleListHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/RequestRoleTokenListHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/RequestRoleTokenListHandler.java
@@ -6,8 +6,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.RoleTokenListPacket;
+import org.kareha.hareka.server.session.Session;

 public final class RequestRoleTokenListHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/RequestSettingsHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/RequestSettingsHandler.java
@@ -6,8 +6,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.SettingsPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class RequestSettingsHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/SaveHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/SaveHandler.java
@@ -8,7 +8,7 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.Saver;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class SaveHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/SetDefaultTilePatternHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/SetDefaultTilePatternHandler.java
@@ -10,7 +10,7 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class SetDefaultTilePatternHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/SetMarkHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/SetMarkHandler.java
@@ -6,8 +6,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.field.FieldPosition;
+import org.kareha.hareka.server.session.Session;

 public final class SetMarkHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/SetRegionListHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/SetRegionListHandler.java
@@ -10,8 +10,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.field.ServerSimpleRegion;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class SetRegionListHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/SetRescueMethodsEnabledHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/SetRescueMethodsEnabledHandler.java
@@ -7,7 +7,7 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class SetRescueMethodsEnabledHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/SetUserRegistrationModeHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/SetUserRegistrationModeHandler.java
@@ -7,7 +7,7 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;
 import org.kareha.hareka.user.UserRegistrationMode;

--- a/server/src/main/java/org/kareha/hareka/server/handler/ShutdownHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/ShutdownHandler.java
@@ -8,7 +8,7 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.Rebooter;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class ShutdownHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/TeleportToCenterHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/TeleportToCenterHandler.java
@@ -8,8 +8,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.field.FieldPosition;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.server.user.User;

 public final class TeleportToCenterHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/TeleportToPlacementRecordHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/TeleportToPlacementRecordHandler.java
@@ -7,8 +7,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.field.PlacementRecord;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class TeleportToPlacementRecordHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/TileHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/TileHandler.java
@@ -12,8 +12,8 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.ServerConstants;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.RequestPowPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.Permission;

 public final class TileHandler implements Handler<Session> {
--- a/server/src/main/java/org/kareha/hareka/server/handler/TokenHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/TokenHandler.java
@@ -7,8 +7,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.game.TokenReceiver;
+import org.kareha.hareka.server.session.Session;

 public final class TokenHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/UndefineRoleHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/UndefineRoleHandler.java
@@ -9,8 +9,8 @@ import org.kareha.hareka.protocol.Handler;
 import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.RoleListPacket;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.server.user.RolesLogRecord;
 import org.kareha.hareka.user.Permission;

--- a/server/src/main/java/org/kareha/hareka/server/handler/UseActiveSkillHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/UseActiveSkillHandler.java
@@ -10,8 +10,8 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.entity.FieldEntity;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.CooldownPacket;
+import org.kareha.hareka.server.session.Session;

 public final class UseActiveSkillHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/handler/UseItemHandler.java
+++ b/server/src/main/java/org/kareha/hareka/server/handler/UseItemHandler.java
@@ -8,8 +8,8 @@ import org.kareha.hareka.protocol.HandlerException;
 import org.kareha.hareka.protocol.ProtocolException;
 import org.kareha.hareka.protocol.ProtocolInput;
 import org.kareha.hareka.server.entity.FieldEntity;
-import org.kareha.hareka.server.external.Session;
 import org.kareha.hareka.server.packet.CooldownPacket;
+import org.kareha.hareka.server.session.Session;

 public final class UseItemHandler implements Handler<Session> {

--- a/server/src/main/java/org/kareha/hareka/server/net/AbstractServer.java
+++ b/server/src/main/java/org/kareha/hareka/server/net/AbstractServer.java
@@ -10,7 +10,7 @@ import java.util.logging.Logger;
 import org.kareha.hareka.annotation.GuardedBy;
 import org.kareha.hareka.annotation.Private;

-public sealed abstract class AbstractServer implements Server permits SecureServer {
+public sealed abstract class AbstractServer implements Server permits PlainServer, SecureServer {

 	@Private
 	static final Logger logger = Logger.getLogger(AbstractServer.class.getName());
@@ -28,28 +28,26 @@ public sealed abstract class AbstractServer implements Server permits SecureServ
 		return port;
 	}

-	protected abstract ServerSocket createServerSocket() throws IOException, ServerException;
+	protected abstract ServerSocket createServerSocket() throws IOException, ServerSocketException;

 	@SuppressWarnings("resource")
 	@Override
-	public synchronized boolean start() throws IOException, ServerException {
+	public synchronized void start() throws IOException, IllegalServerStateException, ServerSocketException {
 		if (thread != null) {
-			return false;
+			throw new IllegalServerStateException("Already started");
 		}
 		thread = new ServerThread(createServerSocket());
 		thread.start();
-		return true;
 	}

 	@Override
-	public synchronized boolean stop() throws IOException, InterruptedException {
+	public synchronized void stop() throws IOException, InterruptedException, IllegalServerStateException {
 		if (thread == null) {
-			return false;
+			throw new IllegalServerStateException("Already stopped");
 		}
 		thread.interrupt();
 		thread.join();
 		thread = null;
-		return true;
 	}

 	protected abstract void accepted(Socket clientSocket);
--- a/server/src/main/java/org/kareha/hareka/server/net/IllegalServerStateException.java
+++ b/server/src/main/java/org/kareha/hareka/server/net/IllegalServerStateException.java
@@ -0,0 +1,10 @@
+package org.kareha.hareka.server.net;
+
+@SuppressWarnings("serial")
+public final class IllegalServerStateException extends Exception {
+
+	public IllegalServerStateException(final String message) {
+		super(message);
+	}
+
+}
--- a/server/src/main/java/org/kareha/hareka/server/net/PlainServer.java
+++ b/server/src/main/java/org/kareha/hareka/server/net/PlainServer.java
@@ -0,0 +1,17 @@
+package org.kareha.hareka.server.net;
+
+import java.io.IOException;
+import java.net.ServerSocket;
+
+public non-sealed abstract class PlainServer extends AbstractServer {
+
+	public PlainServer(final int port) {
+		super(port);
+	}
+
+	@Override
+	protected ServerSocket createServerSocket() throws IOException {
+		return new ServerSocket(port());
+	}
+
+}
--- a/server/src/main/java/org/kareha/hareka/server/net/SecureServer.java
+++ b/server/src/main/java/org/kareha/hareka/server/net/SecureServer.java
@@ -17,7 +17,6 @@ import java.security.cert.X509Certificate;

 import javax.net.ssl.KeyManagerFactory;
 import javax.net.ssl.SSLContext;
-import javax.net.ssl.SSLServerSocketFactory;
 import javax.net.ssl.TrustManager;
 import javax.net.ssl.X509TrustManager;

@@ -36,7 +35,7 @@ public non-sealed abstract class SecureServer extends AbstractServer {
 	}

 	@Override
-	protected ServerSocket createServerSocket() throws IOException, ServerException {
+	protected ServerSocket createServerSocket() throws IOException, ServerSocketException {
 		final SSLContext sslContext;
 		try {
 			sslContext = SSLContext.getInstance("TLS");
@@ -56,15 +55,15 @@ public non-sealed abstract class SecureServer extends AbstractServer {
 			} catch (final NoSuchAlgorithmException e) {
 				throw new AssertionError(e);
 			} catch (final CertificateException e) {
-				throw new RuntimeException(e);
+				throw new ServerSocketException(e);
 			} catch (final IOException e) {
-				if (e.getCause() instanceof UnrecoverableKeyException) {
-					throw new ServerException("Store password may be incorrect", e);
+				if (e.getCause() instanceof UnrecoverableKeyException ex) {
+					throw new ServerSocketException("Store password may be incorrect", ex);
 				}
 				throw e;
 			}
 		} catch (final FileNotFoundException e) {
-			throw new ServerException("KeyStore not found", e);
+			throw new ServerSocketException("KeyStore file not found", e);
 		}

 		final KeyManagerFactory keyManagerFactory;
@@ -76,9 +75,9 @@ public non-sealed abstract class SecureServer extends AbstractServer {
 		try {
 			keyManagerFactory.init(keyStore, keyPassword);
 		} catch (final UnrecoverableKeyException e) {
-			throw new ServerException("Key password may be incorrect", e);
+			throw new ServerSocketException("Key password may be incorrect", e);
 		} catch (final KeyStoreException e) {
-			throw new RuntimeException(e);
+			throw new ServerSocketException(e);
 		} catch (final NoSuchAlgorithmException e) {
 			throw new AssertionError(e);
 		}
@@ -88,13 +87,13 @@ public non-sealed abstract class SecureServer extends AbstractServer {
 			@Override
 			public void checkClientTrusted(final X509Certificate[] chain, final String authType)
 					throws CertificateException {
-				// TODO
+				// nothing to do
 			}

 			@Override
 			public void checkServerTrusted(final X509Certificate[] chain, final String authType)
 					throws CertificateException {
-				// TODO
+				// nothing to do
 			}

 			@Override
@@ -105,9 +104,9 @@ public non-sealed abstract class SecureServer extends AbstractServer {
 		try {
 			sslContext.init(km, tm, new SecureRandom());
 		} catch (final KeyManagementException e) {
-			throw new RuntimeException(e);
+			throw new ServerSocketException(e);
 		}
-		final SSLServerSocketFactory socketFactory = sslContext.getServerSocketFactory();
+		final var socketFactory = sslContext.getServerSocketFactory();
 		return socketFactory.createServerSocket(port());
 	}

--- a/server/src/main/java/org/kareha/hareka/server/net/Server.java
+++ b/server/src/main/java/org/kareha/hareka/server/net/Server.java
@@ -2,14 +2,15 @@ package org.kareha.hareka.server.net;

 import java.io.IOException;

-import org.kareha.hareka.server.external.GameServer;
+import org.kareha.hareka.server.session.SessionServer;

-public sealed interface Server permits AbstractServer, GameServer {
+public sealed interface Server permits AbstractServer, SessionServer {

+	// used in logging
 	int port();

-	boolean start() throws IOException, ServerException;
+	void start() throws IOException, IllegalServerStateException, ServerSocketException;

-	boolean stop() throws IOException, InterruptedException;
+	void stop() throws IOException, InterruptedException, IllegalServerStateException;

 }
--- a/server/src/main/java/org/kareha/hareka/server/net/ServerException.java
+++ b/server/src/main/java/org/kareha/hareka/server/net/ServerException.java
@@ -1,14 +0,0 @@
-package org.kareha.hareka.server.net;
-
-@SuppressWarnings("serial")
-public final class ServerException extends Exception {
-
-	public ServerException(final String message) {
-		super(message);
-	}
-
-	public ServerException(final String message, final Throwable cause) {
-		super(message, cause);
-	}
-
-}
--- a/server/src/main/java/org/kareha/hareka/server/net/ServerSocketException.java
+++ b/server/src/main/java/org/kareha/hareka/server/net/ServerSocketException.java
@@ -0,0 +1,22 @@
+package org.kareha.hareka.server.net;
+
+@SuppressWarnings("serial")
+public final class ServerSocketException extends Exception {
+
+	public ServerSocketException() {
+		// do nothing
+	}
+
+	public ServerSocketException(final String message) {
+		super(message);
+	}
+
+	public ServerSocketException(final String message, final Throwable cause) {
+		super(message, cause);
+	}
+
+	public ServerSocketException(final Throwable cause) {
+		super(cause);
+	}
+
+}
--- a/server/src/main/java/org/kareha/hareka/server/session/IllegalSessionStateException.java
+++ b/server/src/main/java/org/kareha/hareka/server/session/IllegalSessionStateException.java
@@ -0,0 +1,10 @@
+package org.kareha.hareka.server.session;
+
+@SuppressWarnings("serial")
+public final class IllegalSessionStateException extends Exception {
+
+	public IllegalSessionStateException(final String message) {
+		super(message);
+	}
+
+}
--- a/server/src/main/java/org/kareha/hareka/server/external/Session.java
+++ b/server/src/main/java/org/kareha/hareka/server/external/Session.java
@@ -1,13 +1,15 @@
-package org.kareha.hareka.server.external;
+package org.kareha.hareka.server.session;

 import java.net.InetAddress;
 import java.net.Socket;
 import java.text.MessageFormat;
 import java.util.Locale;
 import java.util.ResourceBundle;
+import java.util.logging.Level;
 import java.util.logging.Logger;

 import org.kareha.hareka.annotation.GuardedBy;
+import org.kareha.hareka.annotation.NotPrivateForTesting;
 import org.kareha.hareka.annotation.Private;
 import org.kareha.hareka.game.PassiveSkillType;
 import org.kareha.hareka.key.KeyReceiver;
@@ -49,25 +51,31 @@ public final class Session {
 	private Player player;
 	private final DiceRollTable diceRollTable = new DiceRollTable(ServerConstants.DICE_ROLL_HASH_ALGORITHM);

-	// not private for test
+	@NotPrivateForTesting
 	Session(final Context context) {
 		this.context = context;
 		id = context.sessionStatic().next();
 	}

-	// not private for test
+	@NotPrivateForTesting
 	ProtocolSocket<ServerPacketType, Session> newPacketSocket(final Socket socket,
 			final HandlerTable<ServerPacketType, Session> parserTable) {
 		return new ProtocolSocket<ServerPacketType, Session>(socket, parserTable, this) {
 			@Override
 			public void finish() {
 				logoutUser();
-				context.sessions().removeSession(Session.this);
+				try {
+					context.sessions().removeSession(Session.this);
+				} catch (final IllegalSessionStateException e) {
+					logger.log(Level.SEVERE, "", e);
+					return;
+				}
+				logger.info(Session.this.getStamp() + "Disconnected");
 			}
 		};
 	}

-	// not private for test
+	@NotPrivateForTesting
 	void initialize(final Socket socket, final HandlerTable<ServerPacketType, Session> parserTable) {
 		packetSocket = newPacketSocket(socket, parserTable);
 	}
--- a/server/src/main/java/org/kareha/hareka/server/external/SessionId.java
+++ b/server/src/main/java/org/kareha/hareka/server/external/SessionId.java
@@ -1,4 +1,4 @@
-package org.kareha.hareka.server.external;
+package org.kareha.hareka.server.session;

 import org.kareha.hareka.annotation.Immutable;

--- a/server/src/main/java/org/kareha/hareka/server/session/SessionServer.java
+++ b/server/src/main/java/org/kareha/hareka/server/session/SessionServer.java
@@ -1,27 +1,29 @@
-package org.kareha.hareka.server.external;
+package org.kareha.hareka.server.session;

 import java.io.File;
 import java.io.IOException;
 import java.net.Socket;
 import java.text.MessageFormat;
+import java.util.logging.Level;
 import java.util.logging.Logger;

 import org.kareha.hareka.protocol.HandlerTable;
 import org.kareha.hareka.protocol.ServerPacketType;
 import org.kareha.hareka.server.Context;
 import org.kareha.hareka.server.ServerConstants;
+import org.kareha.hareka.server.net.IllegalServerStateException;
 import org.kareha.hareka.server.net.SecureServer;
 import org.kareha.hareka.server.net.Server;
-import org.kareha.hareka.server.net.ServerException;
+import org.kareha.hareka.server.net.ServerSocketException;
 import org.kareha.hareka.server.packet.VersionPacket;

-public final class GameServer implements Server {
+public final class SessionServer implements Server {

-	private static final Logger logger = Logger.getLogger(GameServer.class.getName());
+	private static final Logger logger = Logger.getLogger(SessionServer.class.getName());

 	private final Server server;

-	public GameServer(final Context context, final int port, final File keyStoreFile) {
+	public SessionServer(final Context context, final int port, final File keyStoreFile) {
 		if (keyStoreFile == null) {
 			throw new IllegalArgumentException("keyStoreFile must not be null");
 		}
@@ -31,7 +33,14 @@ public final class GameServer implements Server {
 		class Accepter {
 			void accepted(final Socket clientSocket) {
 				final var session = Session.newInstance(context, clientSocket, parserTable);
-				context.sessions().addSession(session);
+				try {
+					context.sessions().addSession(session);
+				} catch (final IllegalSessionStateException e) {
+					logger.log(Level.SEVERE, "", e);
+					return;
+				}
+				logger.info(session.getStamp() + "Connected");
+
 				session.start();

 				session.write(new VersionPacket());
@@ -54,25 +63,17 @@ public final class GameServer implements Server {
 	}

 	@Override
-	public boolean start() throws IOException, ServerException {
-		if (!server.start()) {
-			logger.warning("Failed to start server; Server is already running.");
-			return false;
-		}
+	public void start() throws IOException, IllegalServerStateException, ServerSocketException {
+		server.start();
 		logger.info(MessageFormat.format("Listening to port {0}", port()));
 		logger.info("Waiting for connections..");
-		return true;
 	}

 	@Override
-	public boolean stop() throws IOException, InterruptedException {
+	public void stop() throws IOException, InterruptedException, IllegalServerStateException {
 		logger.info("Stop Listening..");
-		if (!server.stop()) {
-			logger.warning("Failed to stop server; Server has already been stopped");
-			return false;
-		}
+		server.stop();
 		logger.info("Listening stopped");
-		return true;
 	}

 }
--- a/server/src/main/java/org/kareha/hareka/server/external/SessionStatic.java
+++ b/server/src/main/java/org/kareha/hareka/server/external/SessionStatic.java
@@ -1,4 +1,4 @@
-package org.kareha.hareka.server.external;
+package org.kareha.hareka.server.session;

 import java.io.File;
 import java.util.concurrent.atomic.AtomicLong;
--- a/server/src/main/java/org/kareha/hareka/server/session/Sessions.java
+++ b/server/src/main/java/org/kareha/hareka/server/session/Sessions.java
@@ -0,0 +1,43 @@
+package org.kareha.hareka.server.session;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
+
+import org.kareha.hareka.annotation.GuardedBy;
+import org.kareha.hareka.annotation.ThreadSafe;
+
+@ThreadSafe
+public final class Sessions {
+
+	@GuardedBy("this")
+	private final Set<Session> sessions = new HashSet<>();
+
+	public synchronized void addSession(final Session session) throws IllegalSessionStateException {
+		final var success = sessions.add(session);
+		if (!success) {
+			throw new IllegalSessionStateException("Already connected");
+		}
+	}
+
+	public synchronized void removeSession(final Session session) throws IllegalSessionStateException {
+		final var success = sessions.remove(session);
+		if (!success) {
+			throw new IllegalSessionStateException("Already disconnected");
+		}
+	}
+
+	public synchronized Collection<Session> getSessions() {
+		if (sessions.isEmpty()) {
+			return Collections.emptyList();
+		}
+		return new ArrayList<>(sessions);
+	}
+
+	public synchronized int sizeOfSessions() {
+		return sessions.size();
+	}
+
+}
--- a/server/src/main/java/org/kareha/hareka/server/user/IdCipher.java
+++ b/server/src/main/java/org/kareha/hareka/server/user/IdCipher.java
@@ -19,7 +19,7 @@ import org.kareha.hareka.annotation.GuardedBy;
 import org.kareha.hareka.annotation.Private;
 import org.kareha.hareka.annotation.ThreadSafe;
 import org.kareha.hareka.server.entity.EntityId;
-import org.kareha.hareka.server.external.SessionId;
+import org.kareha.hareka.server.session.SessionId;
 import org.kareha.hareka.user.UserId;

 import jakarta.xml.bind.annotation.XmlAccessType;
--- a/server/src/main/java/org/kareha/hareka/server/user/User.java
+++ b/server/src/main/java/org/kareha/hareka/server/user/User.java
@@ -19,7 +19,7 @@ import org.kareha.hareka.annotation.Private;
 import org.kareha.hareka.annotation.ThreadSafe;
 import org.kareha.hareka.key.KeyXml;
 import org.kareha.hareka.server.entity.EntityId;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.tool.JaxbUtil;
 import org.kareha.hareka.user.UserId;

--- a/server/src/main/java/org/kareha/hareka/server/user/Users.java
+++ b/server/src/main/java/org/kareha/hareka/server/user/Users.java
@@ -13,7 +13,7 @@ import java.util.logging.Logger;
 import org.kareha.hareka.annotation.GuardedBy;
 import org.kareha.hareka.persistent.PersistentHashTable;
 import org.kareha.hareka.protocol.ProtocolException;
-import org.kareha.hareka.server.external.Session;
+import org.kareha.hareka.server.session.Session;
 import org.kareha.hareka.user.UserId;
 import org.kareha.hareka.user.UserStatic;
 import org.kareha.hareka.util.FileUtil;
--- a/util/src/main/java/org/kareha/hareka/annotation/NotFinalForTesting.java
+++ b/util/src/main/java/org/kareha/hareka/annotation/NotFinalForTesting.java
@@ -0,0 +1,14 @@
+package org.kareha.hareka.annotation;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.SOURCE)
+@Target({ ElementType.TYPE, ElementType.CONSTRUCTOR, ElementType.FIELD, ElementType.METHOD })
+@Documented
+public @interface NotFinalForTesting {
+	// marker annotation
+}
--- a/util/src/main/java/org/kareha/hareka/annotation/NotPrivateForTesting.java
+++ b/util/src/main/java/org/kareha/hareka/annotation/NotPrivateForTesting.java
@@ -0,0 +1,14 @@
+package org.kareha.hareka.annotation;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.SOURCE)
+@Target({ ElementType.TYPE, ElementType.CONSTRUCTOR, ElementType.FIELD, ElementType.METHOD })
+@Documented
+public @interface NotPrivateForTesting {
+	// marker annotation
+}