replace singletons

management/src/main/java/eu/jonahbauer/chat/server/management/ChatBotSupportMXBean.java

@@ -14,7 +14,7 @@ import java.util.List;
 public interface ChatBotSupportMXBean {
 
     @SneakyThrows
-    static @NotNull ObjectName getObjectName(String name) {
+    static @NotNull ObjectName getObjectName(@NotNull String name) {
         return ObjectName.getInstance(STR."eu.jonahbauer.chat.bot.server:component=ChatBots,name=\{quote(name)}");
     }
 

server/src/main/java/eu/jonahbauer/chat/server/Main.java

@@ -1,30 +1,32 @@
 package eu.jonahbauer.chat.server;
 
 import eu.jonahbauer.chat.server.bot.ChatBotSupervisor;
-import eu.jonahbauer.chat.server.management.impl.ChatBotManager;
-import eu.jonahbauer.chat.server.management.impl.SocketManager;
 import eu.jonahbauer.chat.server.socket.SocketSupervisor;
+import eu.jonahbauer.chat.server.util.Lazy.MutableLazy;
 
+import javax.management.JMException;
 import java.io.IOException;
 import java.util.concurrent.CountDownLatch;
 
 public class Main {
 
-    public static void main(String[] args) throws IOException, InterruptedException {
+    public static void main(String[] args) throws IOException, InterruptedException, JMException {
-        // initialize ChatBotManager and SocketManager
-        var _ = ChatBotManager.INSTANCE;
-        var _ = SocketManager.INSTANCE;
-
         var config = Config.load();
-        ChatBotSupervisor.INSTANCE.start(config);
+        var chatBotSupervisorLazy = new MutableLazy<ChatBotSupervisor>();
-        SocketSupervisor.INSTANCE.start(config);
+        var socketSupervisorLazy = new MutableLazy<SocketSupervisor>();
+        try (
+                var chatBotSupervisor = chatBotSupervisorLazy.set(new ChatBotSupervisor(socketSupervisorLazy));
+                var socketSupervisor = socketSupervisorLazy.set(new SocketSupervisor(chatBotSupervisorLazy))
+        ) {
+            chatBotSupervisor.start(config);
+            socketSupervisor.start(config);
 
-        try {
+            try {
-            // keep main thread running
+                // keep main thread running
-            new CountDownLatch(1).await();
+                new CountDownLatch(1).await();
-        } catch (InterruptedException e) {
+            } catch (InterruptedException _) {
-            SocketSupervisor.INSTANCE.stop();
+                // ignore
-            ChatBotSupervisor.INSTANCE.stop();
+            }
         }
     }
 }

server/src/main/java/eu/jonahbauer/chat/server/bot/ChatBotSupervisor.java

@@ -6,32 +6,43 @@ import eu.jonahbauer.chat.bot.config.BotConfig;
 import eu.jonahbauer.chat.bot.impl.BotCreationException;
 import eu.jonahbauer.chat.bot.impl.ChatBotFactory;
 import eu.jonahbauer.chat.server.Config;
+import eu.jonahbauer.chat.server.management.impl.ChatBotManager;
 import eu.jonahbauer.chat.server.management.impl.ChatBotSupport;
 import eu.jonahbauer.chat.server.socket.SocketSupervisor;
+import eu.jonahbauer.chat.server.util.Lazy;
 import lombok.extern.log4j.Log4j2;
 import org.jetbrains.annotations.Blocking;
 import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NonBlocking;
 import org.jetbrains.annotations.NotNull;
 
+import javax.management.JMException;
 import java.time.Duration;
 import java.time.Instant;
 import java.util.*;
 import java.util.concurrent.ArrayBlockingQueue;
 import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.locks.ReentrantLock;
 
 @Log4j2
-public enum ChatBotSupervisor {
+public final class ChatBotSupervisor implements AutoCloseable {
-    INSTANCE;
-
     private static final Duration POST_EXPIRATION = Duration.ofSeconds(2);
     private static final int MESSAGE_QUEUE_SIZE = 10;
 
     /**
      * Map of running bots indexed by their name.
      */
-    private final @NotNull Map<@NotNull String, @NotNull RunningBot> bots = new HashMap<>();
+    private final @NotNull ConcurrentMap<@NotNull String, @NotNull RunningBot> bots = new ConcurrentHashMap<>();
+    private final @NotNull ReentrantLock lock = new ReentrantLock();
+    private final @NotNull Lazy<SocketSupervisor> socketSupervisor;
+
+    public ChatBotSupervisor(@NotNull Lazy<SocketSupervisor> socketSupervisor) throws JMException {
+        ChatBotManager.init(this);
+        this.socketSupervisor = socketSupervisor;
+    }
 
     /**
      * Dispatches the message to all running bots. If a bot has too many messages queued up, the message may not be
@@ -52,9 +63,16 @@ public enum ChatBotSupervisor {
      * @param config a configuration
      * @throws IllegalStateException if any bots are running already
      */
-    public synchronized void start(@NotNull Config config) {
+    public void start(@NotNull Config config) {
-        if (!bots.isEmpty()) throw new IllegalStateException("start(Config) may not be used when any bots are running already");
+        lock.lock();
-        config.bots().forEach(this::start);
+        try {
+            if (!bots.isEmpty()) {
+                throw new IllegalStateException("start(Config) may not be used when any bots are running already");
+            }
+            config.bots().forEach(this::start);
+        } finally {
+            lock.unlock();
+        }
     }
 
     /**
@@ -64,7 +82,7 @@ public enum ChatBotSupervisor {
      * @param channels the channels the bot will be active in
      * @throws BotCreationException if the bot could not be created
      */
-    public synchronized void start(@NotNull String name, @NotNull String type, @NotNull List<String> channels) {
+    public void start(@NotNull String name, @NotNull String type, @NotNull List<String> channels) {
         start(name, BotConfig.builder().type(type).channels(channels).build());
     }
 
@@ -74,9 +92,16 @@ public enum ChatBotSupervisor {
      * @param config the bot configuration
      * @throws BotCreationException if the bot could not be created
      */
-    public synchronized void start(@NotNull String name, @NotNull BotConfig config) {
+    public void start(@NotNull String name, @NotNull BotConfig config) {
-        if (bots.containsKey(name)) throw new BotCreationException("Duplicate bot name: " + name);
+        lock.lock();
-        bots.put(name, new RunningBot(name, config));
+        try {
+            if (bots.containsKey(name)) {
+                throw new BotCreationException("Duplicate bot name: " + name);
+            }
+            bots.put(name, new RunningBot(name, config));
+        } finally {
+            lock.unlock();
+        }
     }
 
     /**
@@ -87,10 +112,13 @@ public enum ChatBotSupervisor {
     public void stop(@NotNull String name) throws InterruptedException {
         RunningBot bot;
 
-        synchronized (this) {
+        lock.lock();
+        try {
             bot = bots.remove(name);
             if (bot == null) return;
             bot.stop();
+        } finally {
+            lock.unlock();
         }
 
         bot.join();
@@ -103,12 +131,15 @@ public enum ChatBotSupervisor {
     public void stop() throws InterruptedException {
         var stopped = new ArrayList<RunningBot>();
 
-        synchronized (this) {
+        lock.lock();
+        try {
             for (RunningBot bot : bots.values()) {
                 stopped.add(bot);
                 bot.stop();
             }
             bots.clear();
+        } finally {
+            lock.unlock();
         }
 
         for (var bot : stopped) {
@@ -116,6 +147,11 @@ public enum ChatBotSupervisor {
         }
     }
 
+    @Override
+    public void close() throws InterruptedException {
+        stop();
+    }
+
     /**
      * {@return a map of all currently running bots and their effective config}
      */
@@ -144,10 +180,10 @@ public enum ChatBotSupervisor {
 
     /**
      * Manages a {@link ChatBot} instance running on its own thread. Takes care of recreating the bot after it threw
-     * an exception. {@linkplain ChatBotSupport#register(String, BotConfig) Registers} the bot during construction
+     * an exception. {@linkplain ChatBotSupport#register(ChatBotSupervisor, String, BotConfig) Registers} the bot
-     * and {@linkplain ChatBotSupport#unregister(String) unregisters} it during {@link #stop()}.
+     * during construction and {@linkplain ChatBotSupport#unregister(String) unregisters} it during {@link #stop()}.
      */
-    private static class RunningBot implements Runnable {
+    private class RunningBot implements Runnable {
         private final @NotNull String name;
         private final @NotNull BotConfig config;
         private final @NotNull ChatBotFactory<?> factory;
@@ -163,7 +199,7 @@ public enum ChatBotSupervisor {
             this.factory = getChatBotFactory(config.getType());
 
             log.info("starting bot {}...", name);
-            ChatBotSupport.register(name, config);
+            ChatBotSupport.register(ChatBotSupervisor.this, name, config);
             this.thread = Thread.ofVirtual().name("ChatBot[" + name + "]").start(this);
         }
 
@@ -200,7 +236,7 @@ public enum ChatBotSupervisor {
                     } else if (!bot.getConfig().getChannels().contains(post.post().channel())) {
                         log.debug("Ignoring message {} because channel is not listened to.", post.post());
                     } else {
-                        bot.onMessage(SocketSupervisor.INSTANCE, post.post());
+                        bot.onMessage(ChatBotSupervisor.this.socketSupervisor.get(), post.post());
                     }
                 } catch (InterruptedException _) {
                 }

server/src/main/java/eu/jonahbauer/chat/server/management/impl/AdvancedMBean.java

@@ -5,6 +5,8 @@ import eu.jonahbauer.chat.server.management.annotations.ManagedBean;
 import eu.jonahbauer.chat.server.management.annotations.ManagedOperation;
 import eu.jonahbauer.chat.server.management.annotations.ManagedParameter;
 import lombok.extern.log4j.Log4j2;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import javax.management.*;
 import java.lang.reflect.Method;
@@ -15,13 +17,13 @@ import java.util.Locale;
 import java.util.function.Function;
 
 @Log4j2
-public class AdvancedMBean extends StandardMBean {
+class AdvancedMBean extends StandardMBean {
-    public <T> AdvancedMBean(T implementation) {
+    public AdvancedMBean(@NotNull Object implementation) {
         super(implementation, null, true);
     }
 
     @Override
-    protected String getDescription(MBeanInfo info) {
+    protected @Nullable String getDescription(@Nullable MBeanInfo info) {
         var clazz = getMBeanInterface();
         var annotation = clazz.getAnnotation(ManagedBean.class);
         if (annotation != null && !"".equals(annotation.description())) {
@@ -32,9 +34,7 @@ public class AdvancedMBean extends StandardMBean {
     }
 
     @Override
-    protected int getImpact(MBeanOperationInfo info) {
+    protected int getImpact(@Nullable MBeanOperationInfo info) {
-        if (info == null) return MBeanOperationInfo.UNKNOWN;
-
         var method = findOperation(info);
         var annotation = method != null ? method.getAnnotation(ManagedOperation.class) : null;
         if (annotation != null) {
@@ -45,9 +45,7 @@ public class AdvancedMBean extends StandardMBean {
     }
 
     @Override
-    protected String getDescription(MBeanOperationInfo info) {
+    protected @Nullable String getDescription(@Nullable MBeanOperationInfo info) {
-        if (info == null) return null;
-
         var method = findOperation(info);
         var annotation = method != null ? method.getAnnotation(ManagedOperation.class) : null;
         if (annotation != null && !"".equals(annotation.description())) {
@@ -58,13 +56,9 @@ public class AdvancedMBean extends StandardMBean {
     }
 
     @Override
-    protected String getParameterName(MBeanOperationInfo op, MBeanParameterInfo param, int sequence) {
+    protected @Nullable String getParameterName(@Nullable MBeanOperationInfo op, @Nullable MBeanParameterInfo param, int sequence) {
-        if (op == null) return super.getParameterName(op, param, sequence);
-
         var method = findOperation(op);
-        if (method == null) return super.getParameterName(op, param, sequence);
+        var annotation = method != null ? method.getParameters()[sequence].getAnnotation(ManagedParameter.class) : null;
-
-        var annotation = method.getParameters()[sequence].getAnnotation(ManagedParameter.class);
         if (annotation != null && !"".equals(annotation.name())) {
             return annotation.name();
         } else {
@@ -73,13 +67,9 @@ public class AdvancedMBean extends StandardMBean {
     }
 
     @Override
-    protected String getDescription(MBeanOperationInfo op, MBeanParameterInfo param, int sequence) {
+    protected @Nullable String getDescription(@Nullable MBeanOperationInfo op, @Nullable MBeanParameterInfo param, int sequence) {
-        if (op == null) return super.getParameterName(op, param, sequence);
-
         var method = findOperation(op);
-        if (method == null) return super.getParameterName(op, param, sequence);
+        var annotation = method != null ? method.getParameters()[sequence].getAnnotation(ManagedParameter.class) : null;
-
-        var annotation = method.getParameters()[sequence].getAnnotation(ManagedParameter.class);
         if (annotation != null && !"".equals(annotation.description())) {
             return annotation.description();
         } else {
@@ -88,7 +78,9 @@ public class AdvancedMBean extends StandardMBean {
     }
 
     @Override
-    protected String getDescription(MBeanAttributeInfo info) {
+    protected @Nullable String getDescription(@Nullable MBeanAttributeInfo info) {
+        if (info == null) return super.getDescription(info);
+
         var name = info.getName();
         var type = getType(info, MBeanAttributeInfo::getType);
 
@@ -107,7 +99,7 @@ public class AdvancedMBean extends StandardMBean {
         return super.getDescription(info);
     }
 
-    private <T extends MBeanFeatureInfo> String getType(T info, Function<T, String> getType) {
+    private <T extends MBeanFeatureInfo> String getType(@NotNull T info, @NotNull Function<T, String> getType) {
         var descriptor = info.getDescriptor();
         if (descriptor == null) return getType.apply(info);
 
@@ -119,7 +111,9 @@ public class AdvancedMBean extends StandardMBean {
         }
     }
 
-    private Method findOperation(MBeanOperationInfo info) {
+    private @Nullable Method findOperation(@Nullable MBeanOperationInfo info) {
+        if (info == null) return null;
+
         var name = info.getName();
         var params = new ArrayList<String>();
 
@@ -130,11 +124,11 @@ public class AdvancedMBean extends StandardMBean {
         return findMethod(name, params);
     }
 
-    private Method findMethod(String name, String...parameters) {
+    private @Nullable Method findMethod(@NotNull String name, @NotNull String @NotNull... parameters) {
         return findMethod(name, Arrays.asList(parameters));
     }
 
-    private Method findMethod(String name, List<String> parameters) {
+    private @Nullable Method findMethod(@NotNull String name, @NotNull List<@NotNull String> parameters) {
         var clazz = getMBeanInterface();
         methods: for (var method : clazz.getMethods()) {
             if (!method.getName().equals(name)) continue;
@@ -150,7 +144,7 @@ public class AdvancedMBean extends StandardMBean {
         return null;
     }
 
-    private static String capitalize(String name) {
+    private static @NotNull String capitalize(@NotNull String name) {
         if (name.isEmpty()) return name;
         return name.substring(0, 1).toUpperCase(Locale.ROOT) + name.substring(1);
     }

server/src/main/java/eu/jonahbauer/chat/server/management/impl/ChatBotManager.java

@@ -5,26 +5,31 @@ import eu.jonahbauer.chat.bot.impl.ChatBotFactory;
 import eu.jonahbauer.chat.server.bot.ChatBotSupervisor;
 import eu.jonahbauer.chat.server.management.BotConfigSupport;
 import eu.jonahbauer.chat.server.management.ChatBotManagerMXBean;
-import lombok.SneakyThrows;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Unmodifiable;
 
+import javax.management.JMException;
 import java.lang.management.ManagementFactory;
 import java.util.*;
 import java.util.stream.Collectors;
 
-public enum ChatBotManager implements ChatBotManagerMXBean {
+public final class ChatBotManager implements ChatBotManagerMXBean {
-    INSTANCE;
+    private final @NotNull ChatBotSupervisor supervisor;
 
-    @SneakyThrows
+    public static void init(@NotNull ChatBotSupervisor supervisor) throws JMException {
-    ChatBotManager() {
+        var impl = new ChatBotManager(supervisor);
         var server = ManagementFactory.getPlatformMBeanServer();
-        server.registerMBean(new AdvancedMBean(this), ChatBotManagerMXBean.NAME);
+        server.registerMBean(new AdvancedMBean(impl), ChatBotManagerMXBean.NAME);
+    }
+
+    private ChatBotManager(@NotNull ChatBotSupervisor supervisor) {
+        this.supervisor = Objects.requireNonNull(supervisor);
     }
 
     @Override
     public void start(@NotNull String name, @NotNull String type, @NotNull List<@NotNull String> channels) {
         try {
-            ChatBotSupervisor.INSTANCE.start(name, type, channels);
+            supervisor.start(name, type, channels);
         } catch (BotCreationException ex) {
             throw new IllegalArgumentException(ex.getMessage(), ex.getCause());
         }
@@ -33,7 +38,7 @@ public enum ChatBotManager implements ChatBotManagerMXBean {
     @Override
     public void start(@NotNull String name, @NotNull BotConfigSupport config) {
         try {
-            ChatBotSupervisor.INSTANCE.start(name, config.unwrap());
+            supervisor.start(name, config.unwrap());
         } catch (BotCreationException ex) {
             throw new IllegalArgumentException(ex.getMessage(), ex.getCause());
         }
@@ -41,23 +46,23 @@ public enum ChatBotManager implements ChatBotManagerMXBean {
 
     @Override
     public void stop(@NotNull String name) throws InterruptedException {
-        ChatBotSupervisor.INSTANCE.stop(name);
+        supervisor.stop(name);
     }
 
     @Override
     public void stop() throws InterruptedException {
-        ChatBotSupervisor.INSTANCE.stop();
+        supervisor.stop();
     }
 
     @Override
-    public @NotNull Map<@NotNull String, @NotNull BotConfigSupport> getBots() {
+    public @Unmodifiable @NotNull Map<@NotNull String, @NotNull BotConfigSupport> getBots() {
         var out = new TreeMap<String, BotConfigSupport>();
-        ChatBotSupervisor.INSTANCE.getBots().forEach((key, value) -> out.put(key, new BotConfigSupport(value)));
+        supervisor.getBots().forEach((key, value) -> out.put(key, new BotConfigSupport(value)));
         return Collections.unmodifiableMap(out);
     }
 
     @Override
-    public @NotNull SortedSet<@NotNull String> getBotImplementations() {
+    public @Unmodifiable @NotNull SortedSet<@NotNull String> getBotImplementations() {
         return Collections.unmodifiableSortedSet(
                 ChatBotFactory.implementations().stream()
                         .map(Class::getCanonicalName)

server/src/main/java/eu/jonahbauer/chat/server/management/impl/ChatBotSupport.java

@@ -6,25 +6,29 @@ import eu.jonahbauer.chat.server.management.BotConfigSupport;
 import eu.jonahbauer.chat.server.management.ChatBotSupportMXBean;
 import lombok.Getter;
 import lombok.extern.log4j.Log4j2;
+import org.jetbrains.annotations.NotNull;
 
 import java.lang.management.ManagementFactory;
+import java.util.Objects;
 
 @Getter
 @Log4j2
-public class ChatBotSupport implements ChatBotSupportMXBean {
+public final class ChatBotSupport implements ChatBotSupportMXBean {
-    private final String name;
+    private final @NotNull ChatBotSupervisor supervisor;
-    private final BotConfigSupport config;
+    private final @NotNull String name;
+    private final @NotNull BotConfigSupport config;
 
-    public static void register(String name, BotConfig config) {
+    public static void register(@NotNull ChatBotSupervisor supervisor, @NotNull String name, @NotNull BotConfig config) {
         try {
+            var impl = new ChatBotSupport(supervisor, name, config);
             var server = ManagementFactory.getPlatformMBeanServer();
-            server.registerMBean(new AdvancedMBean(new ChatBotSupport(name, config)), ChatBotSupportMXBean.getObjectName(name));
+            server.registerMBean(new AdvancedMBean(impl), ChatBotSupportMXBean.getObjectName(name));
         } catch (Exception ex) {
             log.error("Could not register bot as an MBean.", ex);
         }
     }
 
-    public static void unregister(String name) {
+    public static void unregister(@NotNull String name) {
         try {
             var server = ManagementFactory.getPlatformMBeanServer();
             server.unregisterMBean(ChatBotSupportMXBean.getObjectName(name));
@@ -33,12 +37,13 @@ public class ChatBotSupport implements ChatBotSupportMXBean {
         }
     }
 
-    private ChatBotSupport(String name, BotConfig config) {
+    private ChatBotSupport(@NotNull ChatBotSupervisor supervisor, @NotNull String name, @NotNull BotConfig config) {
-        this.name = name;
+        this.supervisor = Objects.requireNonNull(supervisor);
+        this.name = Objects.requireNonNull(name);
         this.config = new BotConfigSupport(config);
     }
 
     public void stop() throws InterruptedException {
-        ChatBotSupervisor.INSTANCE.stop(name);
+        supervisor.stop(name);
     }
 }

server/src/main/java/eu/jonahbauer/chat/server/management/impl/SocketManager.java

@@ -2,43 +2,48 @@ package eu.jonahbauer.chat.server.management.impl;
 
 import eu.jonahbauer.chat.server.management.SocketManagerMXBean;
 import eu.jonahbauer.chat.server.socket.SocketSupervisor;
-import lombok.SneakyThrows;
 import org.jetbrains.annotations.NotNull;
 
+import javax.management.JMException;
 import java.lang.management.ManagementFactory;
+import java.util.Objects;
 import java.util.SortedSet;
 
-public enum SocketManager implements SocketManagerMXBean {
+public final class SocketManager implements SocketManagerMXBean {
-    INSTANCE;
+    private final @NotNull SocketSupervisor supervisor;
 
-    @SneakyThrows
+    public static void init(@NotNull SocketSupervisor supervisor) throws JMException {
-    SocketManager() {
+        var impl = new SocketManager(supervisor);
         var server = ManagementFactory.getPlatformMBeanServer();
-        server.registerMBean(new AdvancedMBean(this), SocketManagerMXBean.NAME);
+        server.registerMBean(new AdvancedMBean(impl), SocketManagerMXBean.NAME);
+    }
+
+    private SocketManager(@NotNull SocketSupervisor supervisor) {
+        this.supervisor = Objects.requireNonNull(supervisor);
     }
 
     @Override
     public void setCredentials(@NotNull String username, @NotNull String password) {
-        SocketSupervisor.INSTANCE.setAccount(username, password);
+        supervisor.setAccount(username, password);
     }
 
     @Override
     public void start(@NotNull String channel) {
-        SocketSupervisor.INSTANCE.start(channel);
+        supervisor.start(channel);
     }
 
     @Override
     public void stop(@NotNull String channel) throws InterruptedException {
-        SocketSupervisor.INSTANCE.stop(channel);
+        supervisor.stop(channel);
     }
 
     @Override
     public void stop() throws InterruptedException {
-        SocketSupervisor.INSTANCE.stop();
+        supervisor.stop();
     }
 
     @Override
     public @NotNull SortedSet<@NotNull String> getChannels() {
-        return SocketSupervisor.INSTANCE.getChannels();
+        return supervisor.getChannels();
     }
 }

server/src/main/java/eu/jonahbauer/chat/server/management/impl/SocketSupport.java

@@ -3,30 +3,32 @@ package eu.jonahbauer.chat.server.management.impl;
 import eu.jonahbauer.chat.server.management.SocketState;
 import eu.jonahbauer.chat.server.management.SocketSupportMXBean;
 import eu.jonahbauer.chat.server.socket.SocketSupervisor;
-import lombok.AccessLevel;
 import lombok.Getter;
-import lombok.RequiredArgsConstructor;
 import lombok.extern.log4j.Log4j2;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.lang.management.ManagementFactory;
 import java.util.Date;
+import java.util.Objects;
 
 @Log4j2
 @Getter
-@RequiredArgsConstructor(access = AccessLevel.PRIVATE)
+public final class SocketSupport implements SocketSupportMXBean {
-public class SocketSupport implements SocketSupportMXBean {
+    private final @NotNull SocketSupervisor supervisor;
-    private final String channel;
+    private final @NotNull String channel;
 
-    public static void register(String channel) {
+    public static void register(@NotNull SocketSupervisor supervisor, @NotNull String channel) {
         try {
+            var impl = new SocketSupport(supervisor, channel);
             var server = ManagementFactory.getPlatformMBeanServer();
-            server.registerMBean(new AdvancedMBean(new SocketSupport(channel)), SocketSupportMXBean.getObjectName(channel));
+            server.registerMBean(new AdvancedMBean(impl), SocketSupportMXBean.getObjectName(channel));
         } catch (Exception ex) {
             log.error("Could not register socket as an MBean.", ex);
         }
     }
 
-    public static void unregister(String name) {
+    public static void unregister(@NotNull String name) {
         try {
             var server = ManagementFactory.getPlatformMBeanServer();
             server.unregisterMBean(SocketSupportMXBean.getObjectName(name));
@@ -35,30 +37,35 @@ public class SocketSupport implements SocketSupportMXBean {
         }
     }
 
+    private SocketSupport(@NotNull SocketSupervisor supervisor, @NotNull String channel) {
+        this.supervisor = Objects.requireNonNull(supervisor);
+        this.channel = Objects.requireNonNull(channel);
+    }
+
     @Override
-    public Date getCooldownUntil() {
+    public @Nullable Date getCooldownUntil() {
-        var cooldown = SocketSupervisor.INSTANCE.getCooldownUntil(channel);
+        var cooldown = supervisor.getCooldownUntil(channel);
         return cooldown != null ? Date.from(cooldown) : null;
     }
 
     @Override
-    public SocketState getState() {
+    public @Nullable SocketState getState() {
-        return SocketSupervisor.INSTANCE.getState(channel);
+        return supervisor.getState(channel);
     }
 
 
     @Override
     public void stop() throws InterruptedException {
-        SocketSupervisor.INSTANCE.stop(channel);
+        supervisor.stop(channel);
     }
 
     @Override
     public void restart() {
-        SocketSupervisor.INSTANCE.restart(channel);
+        supervisor.restart(channel);
     }
 
     @Override
-    public void send(String name, String message, boolean bottag, boolean publicid) {
+    public void send(@NotNull String name, @NotNull String message, boolean bottag, boolean publicid) {
-        SocketSupervisor.INSTANCE.send(channel, name, message, bottag, publicid);
+        supervisor.send(channel, name, message, bottag, publicid);
     }
 }

server/src/main/java/eu/jonahbauer/chat/server/socket/SocketSupervisor.java

@@ -8,13 +8,16 @@ import eu.jonahbauer.chat.bot.api.Message;
 import eu.jonahbauer.chat.server.Config;
 import eu.jonahbauer.chat.server.bot.ChatBotSupervisor;
 import eu.jonahbauer.chat.server.management.SocketState;
+import eu.jonahbauer.chat.server.management.impl.SocketManager;
 import eu.jonahbauer.chat.server.management.impl.SocketSupport;
+import eu.jonahbauer.chat.server.util.Lazy;
 import lombok.SneakyThrows;
 import lombok.extern.log4j.Log4j2;
 import org.apache.logging.log4j.Level;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import javax.management.JMException;
 import java.io.IOException;
 import java.net.CookieManager;
 import java.net.URI;
@@ -32,9 +35,7 @@ import java.util.concurrent.locks.ReentrantLock;
 import static eu.jonahbauer.chat.server.util.UrlTemplateProcessor.URL;
 
 @Log4j2
-public enum SocketSupervisor implements Chat {
+public final class SocketSupervisor implements Chat, AutoCloseable {
-    INSTANCE;
-
     private static final URI AUTH_SERVER = URI.create("https://chat.qed-verein.de/rubychat/account");
     private static final String ORIGIN = "https://chat.qed-verein.de";
     private static final String SERVER = "wss://chat.qed-verein.de/websocket?position=0&version=2&channel=";
@@ -49,6 +50,13 @@ public enum SocketSupervisor implements Chat {
     private final @NotNull CookieManager cookie = new CookieManager();
     private final @NotNull HttpClient client = HttpClient.newBuilder().cookieHandler(cookie).build();
     private final @NotNull ConcurrentMap<@NotNull String, @NotNull ChatClient> sockets = new ConcurrentHashMap<>();
+    private final @NotNull Lazy<ChatBotSupervisor> chatBotSupervisor;
+    private final @NotNull ReentrantLock lock = new ReentrantLock();
+
+    public SocketSupervisor(@NotNull Lazy<ChatBotSupervisor> chatBotSupervisor) throws JMException {
+        SocketManager.init(this);
+        this.chatBotSupervisor = chatBotSupervisor;
+    }
 
     public void setAccount(@NotNull Config.Account account) {
         this.account = Objects.requireNonNull(account, "account");
@@ -82,11 +90,18 @@ public enum SocketSupervisor implements Chat {
      * @param config a configuration
      * @throws IllegalStateException if any sockets are already running
      */
-    public synchronized void start(@NotNull Config config) {
+    public void start(@NotNull Config config) {
-        if (!this.sockets.isEmpty()) throw new IllegalStateException("start(Config) may not be used when any sockets are running already");
+        lock.lock();
+        try {
+            if (!this.sockets.isEmpty()) {
+                throw new IllegalStateException("start(Config) may not be used when any sockets are running already");
+            }
 
-        setAccount(config.account());
+            setAccount(config.account());
-        config.channels().forEach(this::start);
+            config.channels().forEach(this::start);
+        } finally {
+            lock.unlock();
+        }
     }
 
     /**
@@ -94,11 +109,18 @@ public enum SocketSupervisor implements Chat {
      * @param channel the channel
      * @throws IllegalStateException if a socket is already connected to that channel
      */
-    public synchronized void start(@NotNull String channel) {
+    public void start(@NotNull String channel) {
-        if (sockets.containsKey(channel)) throw new SocketCreationException("Duplicate channel: " + channel);
+        lock.lock();
+        try {
+            if (sockets.containsKey(channel)) {
+                throw new SocketCreationException("Duplicate channel: " + channel);
+            }
 
-        var socket = new ChatClient(channel);
+            var socket = new ChatClient(channel);
-        this.sockets.put(channel, socket);
+            this.sockets.put(channel, socket);
+        } finally {
+            lock.unlock();
+        }
     }
 
     /**
@@ -151,6 +173,11 @@ public enum SocketSupervisor implements Chat {
         }
     }
 
+    @Override
+    public void close() throws InterruptedException {
+        stop();
+    }
+
     public @NotNull SortedSet<@NotNull String> getChannels() {
         return Collections.unmodifiableSortedSet(new TreeSet<>(sockets.keySet()));
     }
@@ -191,7 +218,7 @@ public enum SocketSupervisor implements Chat {
         return credentials;
     }
 
-    private record Credentials(String userid, String pwhash) {}
+    private record Credentials(@NotNull String userid, @NotNull String pwhash) {}
 
 
     private sealed interface ChatClientState {
@@ -218,7 +245,7 @@ public enum SocketSupervisor implements Chat {
     }
 
     private final class ChatClient implements WebSocket.Listener, ChatClientState {
-        private final String channel;
+        private final @NotNull String channel;
         private final @NotNull ReentrantLock lock = new ReentrantLock();
         private final @NotNull CountDownLatch stopped = new CountDownLatch(1);
 
@@ -227,7 +254,7 @@ public enum SocketSupervisor implements Chat {
 
         public ChatClient(@NotNull String channel) {
             this.channel = channel;
-            SocketSupport.register(channel);
+            SocketSupport.register(SocketSupervisor.this, channel);
             this.state.onEnter();
         }
 
@@ -427,7 +454,7 @@ public enum SocketSupervisor implements Chat {
 
                     if (message instanceof Message.Post post) {
                         delay = post.id() + 1;
-                        ChatBotSupervisor.INSTANCE.onMessage(post);
+                        SocketSupervisor.this.chatBotSupervisor.get().onMessage(post);
                     }
                 } catch (JsonProcessingException e) {
                     log.warn("Could not parse as message: {}", text, e);

server/src/main/java/eu/jonahbauer/chat/server/util/Lazy.java

@@ -0,0 +1,26 @@
+package eu.jonahbauer.chat.server.util;
+
+import org.jetbrains.annotations.NotNull;
+
+import java.util.Objects;
+
+public interface Lazy<T> {
+    @NotNull T get();
+
+    class MutableLazy<T> implements Lazy<T> {
+        private T value;
+
+        @Override
+        public @NotNull T get() {
+            var value = this.value;
+            if (value == null) throw new IllegalStateException();
+            return value;
+        }
+
+        public @NotNull T set(@NotNull T value) {
+            if (this.value != null) throw new IllegalStateException();
+            this.value = Objects.requireNonNull(value);
+            return value;
+        }
+    }
+}