web: Remove old variable for the nodejs plugin

bot/src/main/java/de/hhhammer/dchat/bot/App.java

@@ -4,47 +4,47 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import com.zaxxer.hikari.HikariConfig;
 import com.zaxxer.hikari.HikariDataSource;
 import de.hhhammer.dchat.bot.openai.ChatGPTService;
-import de.hhhammer.dchat.db.ServerDBService;
+import de.hhhammer.dchat.db.PostgresServerDBService;
-import de.hhhammer.dchat.db.UserDBService;
+import de.hhhammer.dchat.db.PostgresUserDBService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.net.http.HttpClient;
 
-public class App {
+public final class App {
     private static final Logger logger = LoggerFactory.getLogger(App.class);
 
-    public static void main(String[] args) {
+    public static void main(final String[] args) {
-        String discordApiKey = System.getenv("DISCORD_API_KEY");
+        final String discordApiKey = System.getenv("DISCORD_API_KEY");
         if (discordApiKey == null) {
             logger.error("Missing environment variables: DISCORD_API_KEY");
             System.exit(1);
         }
-        String openaiApiKey = System.getenv("OPENAI_API_KEY");
+        final String openaiApiKey = System.getenv("OPENAI_API_KEY");
         if (openaiApiKey == null) {
             logger.error("Missing environment variables: OPENAI_API_KEY");
             System.exit(1);
         }
-        String postgresUser = System.getenv("POSTGRES_USER");
+        final String postgresUser = System.getenv("POSTGRES_USER");
-        String postgresPassword = System.getenv("POSTGRES_PASSWORD");
+        final String postgresPassword = System.getenv("POSTGRES_PASSWORD");
-        String postgresUrl = System.getenv("POSTGRES_URL");
+        final String postgresUrl = System.getenv("POSTGRES_URL");
         if (postgresUser == null || postgresPassword == null || postgresUrl == null) {
             logger.error("Missing environment variables: POSTGRES_USER and/or POSTGRES_PASSWORD and/or POSTGRES_URL");
             System.exit(1);
         }
 
-        var chatGPTService = new ChatGPTService(openaiApiKey, HttpClient.newHttpClient(), new ObjectMapper());
+        final var chatGPTService = new ChatGPTService(openaiApiKey, HttpClient.newHttpClient(), new ObjectMapper());
 
-        var config = new HikariConfig();
+        final var config = new HikariConfig();
         config.setJdbcUrl(postgresUrl);
         config.setUsername(postgresUser);
         config.setPassword(postgresPassword);
 
         try (var ds = new HikariDataSource(config)) {
-            var serverDBService = new ServerDBService(ds);
+            final var serverDBService = new PostgresServerDBService(ds);
-            var userDBService = new UserDBService(ds);
+            final var userDBService = new PostgresUserDBService(ds);
 
-            var discordBot = new DiscordBot(serverDBService, userDBService, chatGPTService, discordApiKey);
+            final var discordBot = new DiscordBot(serverDBService, userDBService, chatGPTService, discordApiKey);
             discordBot.run();
         }
     }

bot/src/main/java/de/hhhammer/dchat/bot/DiscordBot.java

@@ -9,6 +9,7 @@ import de.hhhammer.dchat.db.UserDBService;
 import org.javacord.api.DiscordApi;
 import org.javacord.api.DiscordApiBuilder;
 import org.javacord.api.interaction.SlashCommand;
+import org.javacord.api.interaction.SlashCommandInteraction;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -16,7 +17,7 @@ import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 
-public class DiscordBot implements Runnable {
+public final class DiscordBot implements Runnable {
     private static final Logger logger = LoggerFactory.getLogger(DiscordBot.class);
 
     private final ServerDBService serverDBService;
@@ -24,7 +25,7 @@ public class DiscordBot implements Runnable {
     private final ChatGPTService chatGPTService;
     private final String discordApiKey;
 
-    public DiscordBot(ServerDBService serverDBService, UserDBService userDBService, ChatGPTService chatGPTService, String discordApiKey) {
+    public DiscordBot(final ServerDBService serverDBService, final UserDBService userDBService, final ChatGPTService chatGPTService, final String discordApiKey) {
         this.serverDBService = serverDBService;
         this.userDBService = userDBService;
         this.chatGPTService = chatGPTService;
@@ -34,29 +35,29 @@ public class DiscordBot implements Runnable {
     @Override
     public void run() {
         logger.info("Starting Discord application");
-        DiscordApi discordApi = new DiscordApiBuilder()
+        final DiscordApi discordApi = new DiscordApiBuilder()
                 .setToken(discordApiKey)
                 .login()
                 .join();
-        discordApi.setMessageCacheSize(10, 60*60);
+        discordApi.setMessageCacheSize(10, 60 * 60);
-        var future = new CompletableFuture<Void>();
+        final var future = new CompletableFuture<Void>();
         Runtime.getRuntime().addShutdownHook(Thread.ofVirtual().unstarted(() -> {
             logger.info("Shutting down Discord application");
             discordApi.disconnect().thenAccept(future::complete);
         }));
-        var token = SlashCommand.with("tokens", "Check how many tokens where spend on this server")
+        final SlashCommand token = SlashCommand.with("tokens", "Check how many tokens where spend on this server")
                 .createGlobal(discordApi)
                 .join();
 
         discordApi.addSlashCommandCreateListener(event -> {
             logger.debug("Event? " + event.getSlashCommandInteraction().getFullCommandName());
-            var command = event.getSlashCommandInteraction();
+            final SlashCommandInteraction command = event.getSlashCommandInteraction();
             if (token.getFullCommandNames().contains(command.getFullCommandName())) {
                 event.getInteraction()
                         .respondLater()
                         .orTimeout(30, TimeUnit.SECONDS)
                         .thenAccept((interactionOriginalResponseUpdater) -> {
-                            var tokens = event.getInteraction().getServer().isPresent() ?
+                            final long tokens = event.getInteraction().getServer().isPresent() ?
                                     this.serverDBService.tokensOfLast30Days(String.valueOf(event.getInteraction().getServer().get().getId())) :
                                     this.userDBService.tokensOfLast30Days(String.valueOf(event.getInteraction().getUser().getId()));
                             interactionOriginalResponseUpdater.setContent("" + tokens).update();

bot/src/main/java/de/hhhammer/dchat/bot/discord/MessageCreateHandler.java

@@ -9,17 +9,17 @@ import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 
-public class MessageCreateHandler implements MessageCreateListener {
+public final class MessageCreateHandler implements MessageCreateListener {
     private static final Logger logger = LoggerFactory.getLogger(MessageCreateHandler.class);
 
     private final MessageHandler messageHandler;
 
-    public MessageCreateHandler(MessageHandler messageHandler) {
+    public MessageCreateHandler(final MessageHandler messageHandler) {
         this.messageHandler = messageHandler;
     }
 
     @Override
-    public void onMessageCreate(MessageCreateEvent event) {
+    public void onMessageCreate(final MessageCreateEvent event) {
         Thread.ofVirtual().start(() -> {
             if (!event.canYouReadContent() || event.getMessageAuthor().isBotUser() || !isNormalOrReplyMessageType(event)) {
                 return;
@@ -36,15 +36,15 @@ public class MessageCreateHandler implements MessageCreateListener {
             }
             try {
                 this.messageHandler.handle(event);
-            } catch (ResponseException | IOException | InterruptedException e) {
+            } catch (final ResponseException | IOException | InterruptedException e) {
                 logger.error("Reading a message from the listener", e);
                 event.getMessage().reply("Sorry but something went wrong :(");
             }
         });
     }
 
-    private boolean isNormalOrReplyMessageType(MessageCreateEvent event) {
+    private boolean isNormalOrReplyMessageType(final MessageCreateEvent event) {
-        MessageType type = event.getMessage().getType();
+        final MessageType type = event.getMessage().getType();
         return type == MessageType.NORMAL || type == MessageType.REPLY;
     }
 }

bot/src/main/java/de/hhhammer/dchat/bot/discord/ServerMessageHandler.java

@@ -4,7 +4,10 @@ import de.hhhammer.dchat.bot.openai.ChatGPTRequestBuilder;
 import de.hhhammer.dchat.bot.openai.ChatGPTService;
 import de.hhhammer.dchat.bot.openai.MessageContext.ReplyInteraction;
 import de.hhhammer.dchat.bot.openai.ResponseException;
+import de.hhhammer.dchat.bot.openai.models.ChatGPTRequest;
+import de.hhhammer.dchat.bot.openai.models.ChatGPTResponse;
 import de.hhhammer.dchat.db.ServerDBService;
+import de.hhhammer.dchat.db.models.server.ServerConfig;
 import de.hhhammer.dchat.db.models.server.ServerMessage;
 import org.javacord.api.entity.DiscordEntity;
 import org.javacord.api.entity.message.Message;
@@ -17,43 +20,44 @@ import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 import java.util.List;
+import java.util.Optional;
 
-public class ServerMessageHandler implements MessageHandler {
+public final class ServerMessageHandler implements MessageHandler {
 
     private static final Logger logger = LoggerFactory.getLogger(ServerMessageHandler.class);
     private final ServerDBService serverDBService;
     private final ChatGPTService chatGPTService;
 
-    public ServerMessageHandler(ServerDBService serverDBService, ChatGPTService chatGPTService) {
+    public ServerMessageHandler(final ServerDBService serverDBService, final ChatGPTService chatGPTService) {
         this.serverDBService = serverDBService;
         this.chatGPTService = chatGPTService;
     }
 
     @Override
-    public void handle(MessageCreateEvent event) throws ResponseException, IOException, InterruptedException {
+    public void handle(final MessageCreateEvent event) throws ResponseException, IOException, InterruptedException {
-        String content = extractContent(event);
+        final String content = extractContent(event);
-        var serverId = event.getServer().get().getId();
+        final long serverId = event.getServer().get().getId();
-        var systemMessage = this.serverDBService.getConfig(String.valueOf(serverId)).get().systemMessage();
+        final String systemMessage = this.serverDBService.getConfig(String.valueOf(serverId)).get().systemMessage();
-        List<ReplyInteraction> messageContext = event.getMessage().getType() == MessageType.REPLY ? getContextMessages(event) : List.of();
+        final List<ReplyInteraction> messageContext = event.getMessage().getType() == MessageType.REPLY ? getContextMessages(event) : List.of();
-        var request = new ChatGPTRequestBuilder().contextRequest(messageContext, content, systemMessage);
+        final ChatGPTRequest request = new ChatGPTRequestBuilder().contextRequest(messageContext, content, systemMessage);
-        var response = this.chatGPTService.submit(request);
+        final ChatGPTResponse response = this.chatGPTService.submit(request);
         if (response.choices().isEmpty()) {
             event.getMessage().reply("No response available");
             return;
         }
-        var answer = response.choices().get(0).message().content();
+        final String answer = response.choices().get(0).message().content();
         logServerMessage(event, response.usage().totalTokens());
         event.getMessage().reply(answer);
     }
 
     @Override
-    public boolean isAllowed(MessageCreateEvent event) {
+    public boolean isAllowed(final MessageCreateEvent event) {
         if (event.getServer().isEmpty()) {
             return false;
         }
 
-        var serverId = event.getServer().get().getId();
+        final long serverId = event.getServer().get().getId();
-        var config = this.serverDBService.getConfig(String.valueOf(serverId));
+        final Optional<ServerConfig> config = this.serverDBService.getConfig(String.valueOf(serverId));
         if (config.isEmpty()) {
             logger.debug("Not allowed with id: " + serverId);
             return false;
@@ -62,39 +66,39 @@ public class ServerMessageHandler implements MessageHandler {
     }
 
     @Override
-    public boolean exceedsRate(MessageCreateEvent event) {
+    public boolean exceedsRate(final MessageCreateEvent event) {
-        var serverId = String.valueOf(event.getServer().get().getId());
+        final String serverId = String.valueOf(event.getServer().get().getId());
-        var config = this.serverDBService.getConfig(serverId);
+        final Optional<ServerConfig> config = this.serverDBService.getConfig(serverId);
         if (config.isEmpty()) {
             logger.error("Missing configuration for server with id: " + serverId);
             return true;
         }
-        var rateLimit = config.get().rateLimit();
+        final int rateLimit = config.get().rateLimit();
-        var countMessagesInLastMinute = this.serverDBService.countMessagesInLastMinute(serverId);
+        final int countMessagesInLastMinute = this.serverDBService.countMessagesInLastMinute(serverId);
 
         return countMessagesInLastMinute >= rateLimit;
     }
 
     @Override
-    public boolean canHandle(MessageCreateEvent event) {
+    public boolean canHandle(final MessageCreateEvent event) {
         return event.isServerMessage();
     }
 
-    private void logServerMessage(MessageCreateEvent event, int tokens) {
+    private void logServerMessage(final MessageCreateEvent event, final int tokens) {
-        var serverId = event.getServer().map(DiscordEntity::getId).get();
+        final long serverId = event.getServer().map(DiscordEntity::getId).get();
-        var userId = event.getMessageAuthor().getId();
+        final long userId = event.getMessageAuthor().getId();
 
-        var serverMessage = new ServerMessage.NewServerMessage(String.valueOf(serverId), userId, tokens);
+        final var serverMessage = new ServerMessage.NewServerMessage(String.valueOf(serverId), userId, tokens);
         this.serverDBService.addMessage(serverMessage);
     }
 
-    private String extractContent(MessageCreateEvent event) {
+    private String extractContent(final MessageCreateEvent event) {
-        long ownId = event.getApi().getYourself().getId();
+        final long ownId = event.getApi().getYourself().getId();
         return event.getMessageContent().replaceFirst("<" + ownId + "> ", "");
     }
 
     @NotNull
-    private List<ReplyInteraction> getContextMessages(MessageCreateEvent event) {
+    private List<ReplyInteraction> getContextMessages(final MessageCreateEvent event) {
         return event.getMessage()
                 .getMessageReference()
                 .map(MessageReference::getMessage)

bot/src/main/java/de/hhhammer/dchat/bot/discord/UserMessageHandler.java

@@ -4,7 +4,10 @@ import de.hhhammer.dchat.bot.openai.ChatGPTRequestBuilder;
 import de.hhhammer.dchat.bot.openai.ChatGPTService;
 import de.hhhammer.dchat.bot.openai.MessageContext.PreviousInteraction;
 import de.hhhammer.dchat.bot.openai.ResponseException;
+import de.hhhammer.dchat.bot.openai.models.ChatGPTRequest;
+import de.hhhammer.dchat.bot.openai.models.ChatGPTResponse;
 import de.hhhammer.dchat.db.UserDBService;
+import de.hhhammer.dchat.db.models.user.UserConfig;
 import de.hhhammer.dchat.db.models.user.UserMessage;
 import org.javacord.api.event.message.MessageCreateEvent;
 import org.slf4j.Logger;
@@ -12,46 +15,47 @@ import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 import java.util.List;
+import java.util.Optional;
 
-public class UserMessageHandler implements MessageHandler {
+public final class UserMessageHandler implements MessageHandler {
     private static final Logger logger = LoggerFactory.getLogger(UserMessageHandler.class);
     private final UserDBService userDBService;
     private final ChatGPTService chatGPTService;
 
-    public UserMessageHandler(UserDBService userDBService, ChatGPTService chatGPTService) {
+    public UserMessageHandler(final UserDBService userDBService, final ChatGPTService chatGPTService) {
         this.userDBService = userDBService;
         this.chatGPTService = chatGPTService;
     }
 
     @Override
-    public void handle(MessageCreateEvent event) throws ResponseException, IOException, InterruptedException {
+    public void handle(final MessageCreateEvent event) throws ResponseException, IOException, InterruptedException {
-        String content = event.getReadableMessageContent();
+        final String content = event.getReadableMessageContent();
-        var userId = String.valueOf(event.getMessageAuthor().getId());
+        final String userId = String.valueOf(event.getMessageAuthor().getId());
-        var config = this.userDBService.getConfig(userId).get();
+        final UserConfig config = this.userDBService.getConfig(userId).get();
-        var systemMessage = config.systemMessage();
+        final String systemMessage = config.systemMessage();
-        List<PreviousInteraction> context = this.userDBService.getLastMessages(userId, config.contextLength())
+        final List<PreviousInteraction> context = this.userDBService.getLastMessages(userId, config.contextLength())
                 .stream()
                 .map(userMessage -> new PreviousInteraction(userMessage.question(), userMessage.answer()))
                 .toList();
-        var request = new ChatGPTRequestBuilder().contextRequest(context, content, systemMessage);
+        final ChatGPTRequest request = new ChatGPTRequestBuilder().contextRequest(context, content, systemMessage);
-        var response = this.chatGPTService.submit(request);
+        final ChatGPTResponse response = this.chatGPTService.submit(request);
         if (response.choices().isEmpty()) {
             event.getMessage().reply("No response available");
             return;
         }
-        var answer = response.choices().get(0).message().content();
+        final String answer = response.choices().get(0).message().content();
         logUserMessage(event, content, answer, response.usage().totalTokens());
         event.getChannel().sendMessage(answer);
     }
 
     @Override
-    public boolean isAllowed(MessageCreateEvent event) {
+    public boolean isAllowed(final MessageCreateEvent event) {
         if (event.getServer().isPresent()) {
             return false;
         }
 
-        var userId = event.getMessageAuthor().getId();
+        final long userId = event.getMessageAuthor().getId();
-        var config = this.userDBService.getConfig(String.valueOf(userId));
+        final Optional<UserConfig> config = this.userDBService.getConfig(String.valueOf(userId));
         if (config.isEmpty()) {
             logger.debug("Not allowed with id: " + userId);
             return false;
@@ -60,28 +64,28 @@ public class UserMessageHandler implements MessageHandler {
     }
 
     @Override
-    public boolean exceedsRate(MessageCreateEvent event) {
+    public boolean exceedsRate(final MessageCreateEvent event) {
-        var userId = String.valueOf(event.getMessageAuthor().getId());
+        final String userId = String.valueOf(event.getMessageAuthor().getId());
-        var config = this.userDBService.getConfig(userId);
+        final Optional<UserConfig> config = this.userDBService.getConfig(userId);
         if (config.isEmpty()) {
             logger.error("Missing configuration for userId with id: " + userId);
             return true;
         }
-        var rateLimit = config.get().rateLimit();
+        final int rateLimit = config.get().rateLimit();
-        var countMessagesInLastMinute = this.userDBService.countMessagesInLastMinute(userId);
+        final int countMessagesInLastMinute = this.userDBService.countMessagesInLastMinute(userId);
 
         return countMessagesInLastMinute >= rateLimit;
     }
 
     @Override
-    public boolean canHandle(MessageCreateEvent event) {
+    public boolean canHandle(final MessageCreateEvent event) {
         return event.isPrivateMessage();
     }
 
-    private void logUserMessage(MessageCreateEvent event, String question, String answer, int tokens) {
+    private void logUserMessage(final MessageCreateEvent event, final String question, final String answer, final int tokens) {
-        var userId = event.getMessageAuthor().getId();
+        final long userId = event.getMessageAuthor().getId();
 
-        var userMessage = new UserMessage.NewUserMessage(String.valueOf(userId), question, answer, tokens);
+        final UserMessage.NewUserMessage userMessage = new UserMessage.NewUserMessage(String.valueOf(userId), question, answer, tokens);
         this.userDBService.addMessage(userMessage);
     }
 }

bot/src/main/java/de/hhhammer/dchat/bot/openai/ChatGPTRequestBuilder.java

@@ -8,29 +8,19 @@ import org.jetbrains.annotations.NotNull;
 import java.util.ArrayList;
 import java.util.List;
 
-public class ChatGPTRequestBuilder {
+public final class ChatGPTRequestBuilder {
     private static final String smallContextModel = "gpt-3.5-turbo";
     private static final String bigContextModel = "gpt-3.5-turbo-16k";
 
     public ChatGPTRequestBuilder() {
     }
 
-    public ChatGPTRequest contextRequest(List<? extends MessageContext> contextMessages, String message, String systemMessage) {
-        List<ChatGPTRequest.Message> messages = getMessages(contextMessages, message, systemMessage);
-        String contextModel = contextMessages.size() <= 1 ? smallContextModel : bigContextModel;
-        return new ChatGPTRequest(
-                contextModel,
-                messages,
-                0.7f
-        );
-    }
-
     @NotNull
-    private static List<ChatGPTRequest.Message> getMessages(List<? extends MessageContext> contextMessages, String message, String systemMessage) {
+    private static List<ChatGPTRequest.Message> getMessages(final List<? extends MessageContext> contextMessages, final String message, final String systemMessage) {
-        var systemMsg = new ChatGPTRequest.Message("system", systemMessage);
+        final ChatGPTRequest.Message systemMsg = new ChatGPTRequest.Message("system", systemMessage);
-        List<ChatGPTRequest.Message> contextMsgs = getContextMessages(contextMessages);
+        final List<ChatGPTRequest.Message> contextMsgs = getContextMessages(contextMessages);
-        var userMessage = new ChatGPTRequest.Message("user", message);
+        final ChatGPTRequest.Message userMessage = new ChatGPTRequest.Message("user", message);
-        List<ChatGPTRequest.Message> messages = new ArrayList<>();
+        final List<ChatGPTRequest.Message> messages = new ArrayList<>();
         messages.add(systemMsg);
         messages.addAll(contextMsgs);
         messages.add(userMessage);
@@ -38,7 +28,7 @@ public class ChatGPTRequestBuilder {
     }
 
     @NotNull
-    private static List<ChatGPTRequest.Message> getContextMessages(List<? extends MessageContext> contextMessages) {
+    private static List<ChatGPTRequest.Message> getContextMessages(final List<? extends MessageContext> contextMessages) {
         return contextMessages.stream()
                 .map(ChatGPTRequestBuilder::mapContextMessages)
                 .flatMap(List::stream)
@@ -46,7 +36,7 @@ public class ChatGPTRequestBuilder {
     }
 
     @NotNull
-    private static List<ChatGPTRequest.Message> mapContextMessages(MessageContext contextMessage) {
+    private static List<ChatGPTRequest.Message> mapContextMessages(final MessageContext contextMessage) {
         return switch (contextMessage) {
             case PreviousInteraction previousInteractions -> List.of(
                     new ChatGPTRequest.Message("user", previousInteractions.question()),
@@ -56,4 +46,14 @@ public class ChatGPTRequestBuilder {
                     List.of(new ChatGPTRequest.Message("assistant", replyInteractions.answer()));
         };
     }
+
+    public ChatGPTRequest contextRequest(final List<? extends MessageContext> contextMessages, final String message, final String systemMessage) {
+        final List<ChatGPTRequest.Message> messages = getMessages(contextMessages, message, systemMessage);
+        final String contextModel = contextMessages.size() <= 1 ? smallContextModel : bigContextModel;
+        return new ChatGPTRequest(
+                contextModel,
+                messages,
+                0.7f
+        );
+    }
 }

bot/src/main/java/de/hhhammer/dchat/bot/openai/ChatGPTService.java

@@ -5,34 +5,35 @@ import de.hhhammer.dchat.bot.openai.models.ChatGPTRequest;
 import de.hhhammer.dchat.bot.openai.models.ChatGPTResponse;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.net.URI;
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
 import java.time.Duration;
 
-public class ChatGPTService {
+public final class ChatGPTService {
     private static final String url = "https://api.openai.com/v1/chat/completions";
     private final String apiKey;
     private final HttpClient httpClient;
     private final ObjectMapper mapper;
 
-    public ChatGPTService(String apiKey, HttpClient httpClient, ObjectMapper mapper) {
+    public ChatGPTService(final String apiKey, final HttpClient httpClient, final ObjectMapper mapper) {
         this.apiKey = apiKey;
         this.httpClient = httpClient;
         this.mapper = mapper;
     }
 
-    public ChatGPTResponse submit(ChatGPTRequest chatGPTRequest) throws IOException, InterruptedException, ResponseException {
+    public ChatGPTResponse submit(final ChatGPTRequest chatGPTRequest) throws IOException, InterruptedException, ResponseException {
-        var data = mapper.writeValueAsBytes(chatGPTRequest);
+        final byte[] data = mapper.writeValueAsBytes(chatGPTRequest);
-        var request = HttpRequest.newBuilder(URI.create(url))
+        final HttpRequest request = HttpRequest.newBuilder(URI.create(url))
                 .POST(HttpRequest.BodyPublishers.ofByteArray(data))
                 .setHeader("Content-Type", "application/json")
                 .setHeader("Authorization", "Bearer " + this.apiKey)
                 .timeout(Duration.ofMinutes(5))
                 .build();
 
-        var responseStream = httpClient.send(request, HttpResponse.BodyHandlers.ofInputStream());
+        final HttpResponse<InputStream> responseStream = httpClient.send(request, HttpResponse.BodyHandlers.ofInputStream());
         if (responseStream.statusCode() != 200) {
             throw new ResponseException("Response status code was not 200: " + responseStream.statusCode());
         }

bot/src/main/java/de/hhhammer/dchat/bot/openai/ResponseException.java

@@ -1,7 +1,7 @@
 package de.hhhammer.dchat.bot.openai;
 
-public class ResponseException extends Exception {
+public final class ResponseException extends Exception {
-    public ResponseException(String message) {
+    public ResponseException(final String message) {
         super(message);
     }
 }

db/src/main/java/de/hhhammer/dchat/db/DBException.java

@@ -1,7 +1,7 @@
 package de.hhhammer.dchat.db;
 
-public class DBException extends Exception {
+public final class DBException extends Exception {
-    public DBException(String message, Throwable cause) {
+    public DBException(final String message, final Throwable cause) {
         super(message, cause);
     }
 }

db/src/main/java/de/hhhammer/dchat/db/PostgresServerDBService.java

@@ -0,0 +1,202 @@
+package de.hhhammer.dchat.db;
+
+import de.hhhammer.dchat.db.models.server.ServerConfig;
+import de.hhhammer.dchat.db.models.server.ServerMessage;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.sql.DataSource;
+import java.sql.*;
+import java.time.Instant;
+import java.time.temporal.ChronoUnit;
+import java.util.List;
+import java.util.Optional;
+import java.util.stream.StreamSupport;
+
+public final class PostgresServerDBService implements ServerDBService {
+    private static final Logger logger = LoggerFactory.getLogger(PostgresServerDBService.class);
+    private final DataSource dataSource;
+
+    public PostgresServerDBService(final DataSource dataSource) {
+        this.dataSource = dataSource;
+    }
+
+    @Override
+    public Optional<ServerConfig> getConfig(final String serverId) {
+        final var getServerConfig = """
+                SELECT * FROM server_configs WHERE server_id = ?
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getServerConfig)
+        ) {
+            pstmt.setString(1, serverId);
+            final ResultSet resultSet = pstmt.executeQuery();
+            final Iterable<ServerConfig> iterable = () -> new ResultSetIterator<>(resultSet, new ServerConfig.ServerConfigResultSetTransformer());
+            return StreamSupport.stream(iterable.spliterator(), false).findFirst();
+        } catch (final SQLException e) {
+            logger.error("Getting configuration for server with id: " + serverId, e);
+        } catch (final ResultSetIteratorException e) {
+            logger.error("Iterating over ServerConfig ResultSet for server with id: " + serverId, e);
+        }
+        return Optional.empty();
+    }
+
+    @Override
+    public List<ServerConfig> getAllConfigs() throws DBException {
+        final var getAllowedServerSql = """
+                SELECT * FROM server_configs
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getAllowedServerSql)
+        ) {
+            final ResultSet resultSet = pstmt.executeQuery();
+            final Iterable<ServerConfig> iterable = () -> new ResultSetIterator<>(resultSet, new ServerConfig.ServerConfigResultSetTransformer());
+            return StreamSupport.stream(iterable.spliterator(), false).toList();
+        } catch (final SQLException e) {
+            throw new DBException("Loading all configs", e);
+        } catch (final ResultSetIteratorException e) {
+            throw new DBException("Iterating over configs", e);
+        }
+    }
+
+    @Override
+    public Optional<ServerConfig> getConfigBy(final long id) throws DBException {
+        final var getServerConfig = """
+                SELECT * FROM server_configs WHERE id = ?
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getServerConfig)
+        ) {
+            pstmt.setLong(1, id);
+            final ResultSet resultSet = pstmt.executeQuery();
+            final Iterable<ServerConfig> iterable = () -> new ResultSetIterator<>(resultSet, new ServerConfig.ServerConfigResultSetTransformer());
+            return StreamSupport.stream(iterable.spliterator(), false).findFirst();
+        } catch (SQLException e) {
+            throw new DBException("Getting configuration with id: " + id, e);
+        } catch (ResultSetIteratorException e) {
+            throw new DBException("Iterating over ServerConfig ResultSet for id: " + id, e);
+        }
+    }
+
+    @Override
+    public void addConfig(final ServerConfig.NewServerConfig newServerConfig) throws DBException {
+        final var getServerConfig = """
+                INSERT INTO server_configs (server_id, system_message, rate_limit) VALUES (?,?,?)
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getServerConfig)
+        ) {
+            pstmt.setString(1, newServerConfig.serverId());
+            pstmt.setString(2, newServerConfig.systemMessage());
+            pstmt.setInt(3, newServerConfig.rateLimit());
+            final int affectedRows = pstmt.executeUpdate();
+            if (affectedRows == 0) {
+                logger.error("No config added for server with id: " + newServerConfig.serverId());
+            }
+        } catch (final SQLException e) {
+            throw new DBException("Adding configuration to server with id: " + newServerConfig.serverId(), e);
+        }
+    }
+
+    @Override
+    public void updateConfig(final long id, final ServerConfig.NewServerConfig newServerConfig) throws DBException {
+        final var getServerConfig = """
+                UPDATE server_configs SET system_message = ?, rate_limit = ?, server_id = ? WHERE id = ?
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getServerConfig)
+        ) {
+            pstmt.setString(1, newServerConfig.systemMessage());
+            pstmt.setInt(2, newServerConfig.rateLimit());
+            pstmt.setString(3, newServerConfig.serverId());
+            pstmt.setLong(4, id);
+            final int affectedRows = pstmt.executeUpdate();
+            if (affectedRows == 0) {
+                logger.error("No config update for server with id: " + newServerConfig.serverId());
+            }
+        } catch (final SQLException e) {
+            throw new DBException("Adding configuration to server with id: " + newServerConfig.serverId(), e);
+        }
+    }
+
+    @Override
+    public void deleteConfig(final long id) throws DBException {
+        final var getServerConfig = """
+                DELETE FROM server_configs WHERE id = ?
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getServerConfig)
+        ) {
+            pstmt.setLong(1, id);
+            final int affectedRows = pstmt.executeUpdate();
+            if (affectedRows == 0) {
+                logger.error("No config deleted for server with id: " + id);
+            }
+        } catch (final SQLException e) {
+            throw new DBException("Deleting configuration for server with id: " + id, e);
+        }
+    }
+
+    @Override
+    public int countMessagesInLastMinute(final String serverId) {
+        final var getServerConfig = """
+                SELECT count(*) FROM server_messages WHERE server_id = ? AND time <= ? and time >= ?
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getServerConfig)
+        ) {
+            pstmt.setString(1, serverId);
+            final var now = Instant.now();
+            pstmt.setTimestamp(2, Timestamp.from(now));
+            pstmt.setTimestamp(3, Timestamp.from(now.minus(1, ChronoUnit.MINUTES)));
+            final ResultSet resultSet = pstmt.executeQuery();
+            if (resultSet.next()) return resultSet.getInt(1);
+        } catch (final SQLException e) {
+            logger.error("Getting messages for server with id: " + serverId, e);
+        } catch (final ResultSetIteratorException e) {
+            logger.error("Iterating over ServerMessages ResultSet for server with id: " + serverId, e);
+        }
+        return Integer.MAX_VALUE;
+    }
+
+    @Override
+    public void addMessage(final ServerMessage.NewServerMessage serverMessage) {
+        final var getServerConfig = """
+                INSERT INTO server_messages (server_id, user_id, tokens) VALUES (?,?,?)
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getServerConfig)
+        ) {
+            pstmt.setString(1, serverMessage.serverId());
+            pstmt.setLong(2, serverMessage.userId());
+            pstmt.setInt(3, serverMessage.tokens());
+            final int affectedRows = pstmt.executeUpdate();
+            if (affectedRows == 0) {
+                logger.error("No message added for server with id: " + serverMessage.serverId());
+            }
+        } catch (final SQLException e) {
+            logger.error("Adding message to server with id: " + serverMessage.serverId(), e);
+        }
+    }
+
+    @Override
+    public long tokensOfLast30Days(final String serverId) {
+        final var countTokensOfLast30Days = """
+                SELECT sum(tokens) FROM server_messages WHERE server_id = ? AND time < ? AND time >= ?
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(countTokensOfLast30Days)
+        ) {
+            pstmt.setString(1, serverId);
+            final var now = Instant.now();
+            pstmt.setTimestamp(2, Timestamp.from(now));
+            pstmt.setTimestamp(3, Timestamp.from(now.minus(30, ChronoUnit.DAYS)));
+            final ResultSet resultSet = pstmt.executeQuery();
+            if (resultSet.next()) return resultSet.getLong(1);
+        } catch (final SQLException e) {
+            logger.error("Counting tokens of the last 30 days from server with id: " + serverId, e);
+        }
+        logger.error("No tokens found for server with id: " + serverId);
+        return 0;
+    }
+}

db/src/main/java/de/hhhammer/dchat/db/PostgresUserDBService.java

@@ -0,0 +1,226 @@
+package de.hhhammer.dchat.db;
+
+import de.hhhammer.dchat.db.models.user.UserConfig;
+import de.hhhammer.dchat.db.models.user.UserMessage;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.sql.DataSource;
+import java.sql.*;
+import java.time.Instant;
+import java.time.temporal.ChronoUnit;
+import java.util.List;
+import java.util.Optional;
+import java.util.stream.StreamSupport;
+
+public final class PostgresUserDBService implements UserDBService {
+    private static final Logger logger = LoggerFactory.getLogger(PostgresUserDBService.class);
+    private final DataSource dataSource;
+
+    public PostgresUserDBService(final DataSource dataSource) {
+        this.dataSource = dataSource;
+    }
+
+    @Override
+    public Optional<UserConfig> getConfig(final String userId) {
+        final var getServerConfig = """
+                SELECT * FROM user_configs WHERE user_id = ?
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getServerConfig)
+        ) {
+            pstmt.setString(1, userId);
+            final ResultSet resultSet = pstmt.executeQuery();
+            final Iterable<UserConfig> iterable = () -> new ResultSetIterator<>(resultSet, new UserConfig.UserConfigResultSetTransformer());
+            return StreamSupport.stream(iterable.spliterator(), false).findFirst();
+        } catch (final SQLException e) {
+            logger.error("Getting configuration for user with id: " + userId, e);
+        } catch (final ResultSetIteratorException e) {
+            logger.error("Iterating over ServerConfig ResultSet for user with id: " + userId, e);
+        }
+        return Optional.empty();
+    }
+
+    @Override
+    public Optional<UserConfig> getConfigBy(final long id) throws DBException {
+        final var getServerConfig = """
+                SELECT * FROM user_configs WHERE id = ?
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getServerConfig)
+        ) {
+            pstmt.setLong(1, id);
+            final ResultSet resultSet = pstmt.executeQuery();
+            final Iterable<UserConfig> iterable = () -> new ResultSetIterator<>(resultSet, new UserConfig.UserConfigResultSetTransformer());
+            return StreamSupport.stream(iterable.spliterator(), false).findFirst();
+        } catch (final SQLException e) {
+            throw new DBException("Getting configuration id: " + id, e);
+        } catch (final ResultSetIteratorException e) {
+            throw new DBException("Iterating over UserConfig ResultSet with id: " + id, e);
+        }
+    }
+
+    @Override
+    public List<UserConfig> getAllConfigs() throws DBException {
+        final var getServerConfig = """
+                SELECT * FROM user_configs
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getServerConfig)
+        ) {
+            final ResultSet resultSet = pstmt.executeQuery();
+            final Iterable<UserConfig> iterable = () -> new ResultSetIterator<>(resultSet, new UserConfig.UserConfigResultSetTransformer());
+            return StreamSupport.stream(iterable.spliterator(), false).toList();
+        } catch (final SQLException e) {
+            throw new DBException("Getting all configurations", e);
+        } catch (final ResultSetIteratorException e) {
+            throw new DBException("Iterating over all UserConfig ResultSet", e);
+        }
+    }
+
+    @Override
+    public void addConfig(UserConfig.NewUserConfig newUserConfig) throws DBException {
+        final var getServerConfig = """
+                INSERT INTO user_configs (user_id, system_message, context_length, rate_limit) VALUES (?,?,?,?)
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getServerConfig)
+        ) {
+            pstmt.setString(1, newUserConfig.userId());
+            pstmt.setString(2, newUserConfig.systemMessage());
+            pstmt.setInt(3, newUserConfig.contextLength());
+            pstmt.setInt(4, newUserConfig.rateLimit());
+            final int affectedRows = pstmt.executeUpdate();
+            if (affectedRows == 0) {
+                logger.error("No config added for user with id: " + newUserConfig.userId());
+            }
+        } catch (final SQLException e) {
+            throw new DBException("Adding configuration for user with id: " + newUserConfig.userId(), e);
+        }
+    }
+
+    @Override
+    public void updateConfig(final long id, final UserConfig.NewUserConfig newUserConfig) throws DBException {
+        final var getServerConfig = """
+                UPDATE user_configs SET system_message = ?, context_length = ?, rate_limit = ?, user_id = ? WHERE id = ?
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getServerConfig)
+        ) {
+            pstmt.setString(1, newUserConfig.systemMessage());
+            pstmt.setInt(2, newUserConfig.rateLimit());
+            pstmt.setLong(3, newUserConfig.contextLength());
+            pstmt.setString(4, newUserConfig.userId());
+            pstmt.setLong(5, id);
+            final int affectedRows = pstmt.executeUpdate();
+            if (affectedRows == 0) {
+                logger.error("No config update with id: " + id);
+            }
+        } catch (final SQLException e) {
+            throw new DBException("Updating configuration with id: " + id, e);
+        }
+    }
+
+    @Override
+    public void deleteConfig(final long id) throws DBException {
+        final var getServerConfig = """
+                DELETE FROM user_configs WHERE id = ?
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getServerConfig)
+        ) {
+            pstmt.setLong(1, id);
+            final int affectedRows = pstmt.executeUpdate();
+            if (affectedRows == 0) {
+                logger.error("No config deleted for user with id: " + id);
+            }
+        } catch (final SQLException e) {
+            throw new DBException("Deleting configuration with id: " + id, e);
+        }
+    }
+
+    @Override
+    public int countMessagesInLastMinute(final String userId) {
+        final var getServerConfig = """
+                SELECT count(*) FROM user_messages WHERE user_id = ? AND time <= ? and time >= ?
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getServerConfig)
+        ) {
+            pstmt.setString(1, userId);
+            final var now = Instant.now();
+            pstmt.setTimestamp(2, Timestamp.from(now));
+            pstmt.setTimestamp(3, Timestamp.from(now.minus(1, ChronoUnit.MINUTES)));
+            final ResultSet resultSet = pstmt.executeQuery();
+            if (resultSet.next()) return resultSet.getInt(1);
+        } catch (final SQLException e) {
+            logger.error("Getting messages for user with id: " + userId, e);
+        } catch (final ResultSetIteratorException e) {
+            logger.error("Iterating over ServerMessages ResultSet for user with id: " + userId, e);
+        }
+        return Integer.MAX_VALUE;
+    }
+
+    @Override
+    public void addMessage(final UserMessage.NewUserMessage newUserMessage) {
+        final var getServerConfig = """
+                INSERT INTO user_messages (user_id, question, answer, tokens) VALUES (?,?,?,?)
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getServerConfig)
+        ) {
+            pstmt.setString(1, newUserMessage.userId());
+            pstmt.setString(2, newUserMessage.question());
+            pstmt.setString(3, newUserMessage.answer());
+            pstmt.setInt(4, newUserMessage.tokens());
+            final int affectedRows = pstmt.executeUpdate();
+            if (affectedRows == 0) {
+                logger.error("No message added for user with id: " + newUserMessage.userId());
+            }
+        } catch (final SQLException e) {
+            logger.error("Adding message to user with id: " + newUserMessage.userId(), e);
+        }
+    }
+
+    @Override
+    public List<UserMessage> getLastMessages(final String userId, final int limit) {
+        final var getLastMessages = """
+                SELECT * FROM user_messages WHERE user_id = ? ORDER BY time DESC LIMIT ?
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(getLastMessages)
+        ) {
+            pstmt.setString(1, userId);
+            pstmt.setInt(2, limit);
+            final ResultSet resultSet = pstmt.executeQuery();
+            final Iterable<UserMessage> iterable = () -> new ResultSetIterator<>(resultSet, new UserMessage.UserMessageResultSetTransformer());
+            return StreamSupport.stream(iterable.spliterator(), false).toList();
+        } catch (final SQLException e) {
+            logger.error("Fetching last messages for user whit id: " + userId, e);
+        } catch (final ResultSetIteratorException e) {
+            logger.error("Iterating over messages ResultSet from user with id: " + userId, e);
+        }
+        return List.of();
+    }
+
+    @Override
+    public long tokensOfLast30Days(final String userId) {
+        final var countTokensOfLast30Days = """
+                SELECT sum(tokens) FROM user_messages WHERE user_id = ? AND time < ? AND time >= ?
+                """;
+        try (final Connection con = dataSource.getConnection();
+             final PreparedStatement pstmt = con.prepareStatement(countTokensOfLast30Days)
+        ) {
+            pstmt.setString(1, userId);
+            final var now = Instant.now();
+            pstmt.setTimestamp(2, Timestamp.from(now));
+            pstmt.setTimestamp(3, Timestamp.from(now.minus(30, ChronoUnit.DAYS)));
+            final ResultSet resultSet = pstmt.executeQuery();
+            if (resultSet.next()) return resultSet.getLong(1);
+        } catch (final SQLException e) {
+            logger.error("Counting tokens of the last 30 days from user with id: " + userId, e);
+        }
+        logger.error("No tokens found for user with id: " + userId);
+        return 0;
+    }
+}

db/src/main/java/de/hhhammer/dchat/db/ResultSetIterator.java

@@ -4,11 +4,11 @@ import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.util.Iterator;
 
-public class ResultSetIterator<T> implements Iterator<T> {
+public final class ResultSetIterator<T> implements Iterator<T> {
     private final ResultSet resultSet;
     private final ResultSetTransformer<T> transformer;
 
-    public ResultSetIterator(ResultSet resultSet, ResultSetTransformer<T> transformer) {
+    public ResultSetIterator(final ResultSet resultSet, final ResultSetTransformer<T> transformer) {
         this.resultSet = resultSet;
         this.transformer = transformer;
     }

db/src/main/java/de/hhhammer/dchat/db/ResultSetIteratorException.java

@@ -1,7 +1,7 @@
 package de.hhhammer.dchat.db;
 
-public class ResultSetIteratorException extends RuntimeException {
+public final class ResultSetIteratorException extends RuntimeException {
-    public ResultSetIteratorException(Throwable cause) {
+    public ResultSetIteratorException(final Throwable cause) {
         super(cause);
     }
 }

db/src/main/java/de/hhhammer/dchat/db/ServerDBService.java

@@ -2,196 +2,26 @@ package de.hhhammer.dchat.db;
 
 import de.hhhammer.dchat.db.models.server.ServerConfig;
 import de.hhhammer.dchat.db.models.server.ServerMessage;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
-import javax.sql.DataSource;
-import java.sql.*;
-import java.time.Instant;
-import java.time.temporal.ChronoUnit;
 import java.util.List;
 import java.util.Optional;
-import java.util.stream.StreamSupport;
 
-public class ServerDBService {
+public interface ServerDBService {
-    private static final Logger logger = LoggerFactory.getLogger(ServerDBService.class);
+    Optional<ServerConfig> getConfig(String serverId);
-    private final DataSource dataSource;
 
-    public ServerDBService(DataSource dataSource) {
+    List<ServerConfig> getAllConfigs() throws DBException;
-        this.dataSource = dataSource;
-    }
 
-    public Optional<ServerConfig> getConfig(String serverId) {
+    Optional<ServerConfig> getConfigBy(long id) throws DBException;
-        var getServerConfig = """
-                SELECT * FROM server_configs WHERE server_id = ?
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getServerConfig)
-        ) {
-            pstmt.setString(1, serverId);
-            ResultSet resultSet = pstmt.executeQuery();
-            Iterable<ServerConfig> iterable = () -> new ResultSetIterator<>(resultSet, new ServerConfig.ServerConfigResultSetTransformer());
-            return StreamSupport.stream(iterable.spliterator(), false).findFirst();
-        } catch (SQLException e) {
-            logger.error("Getting configuration for server with id: " + serverId, e);
-        } catch (ResultSetIteratorException e) {
-            logger.error("Iterating over ServerConfig ResultSet for server with id: " + serverId, e);
-            return Optional.empty();
-        }
-        return Optional.empty();
-    }
 
-    public List<ServerConfig> getAllConfigs() throws DBException {
+    void addConfig(ServerConfig.NewServerConfig newServerConfig) throws DBException;
-        var getAllowedServerSql = """
-                SELECT * FROM server_configs
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getAllowedServerSql)
-        ) {
-            ResultSet resultSet = pstmt.executeQuery();
-            Iterable<ServerConfig> iterable = () -> new ResultSetIterator<>(resultSet, new ServerConfig.ServerConfigResultSetTransformer());
-            return StreamSupport.stream(iterable.spliterator(), false).toList();
-        } catch (SQLException e) {
-            throw new DBException("Loading all configs", e);
-        } catch (ResultSetIteratorException e) {
-            throw new DBException("Iterating over configs", e);
-        }
-    }
 
-    public Optional<ServerConfig> getConfigBy(long id) throws DBException {
+    void updateConfig(long id, ServerConfig.NewServerConfig newServerConfig) throws DBException;
-        var getServerConfig = """
-                SELECT * FROM server_configs WHERE id = ?
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getServerConfig)
-        ) {
-            pstmt.setLong(1, id);
-            ResultSet resultSet = pstmt.executeQuery();
-            Iterable<ServerConfig> iterable = () -> new ResultSetIterator<>(resultSet, new ServerConfig.ServerConfigResultSetTransformer());
-            return StreamSupport.stream(iterable.spliterator(), false).findFirst();
-        } catch (SQLException e) {
-            throw new DBException("Getting configuration with id: " + id, e);
-        } catch (ResultSetIteratorException e) {
-            throw new DBException("Iterating over ServerConfig ResultSet for id: " + id, e);
-        }
-    }
 
-    public void addConfig(ServerConfig.NewServerConfig newServerConfig) throws DBException {
+    void deleteConfig(long id) throws DBException;
-        var getServerConfig = """
-                INSERT INTO server_configs (server_id, system_message, rate_limit) VALUES (?,?,?)
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getServerConfig)
-        ) {
-            pstmt.setString(1, newServerConfig.serverId());
-            pstmt.setString(2, newServerConfig.systemMessage());
-            pstmt.setInt(3, newServerConfig.rateLimit());
-            int affectedRows = pstmt.executeUpdate();
-            if (affectedRows == 0) {
-                logger.error("No config added for server with id: " + newServerConfig.serverId());
-            }
-        } catch (SQLException e) {
-            throw new DBException("Adding configuration to server with id: " + newServerConfig.serverId(), e);
-        }
-    }
 
-    public void updateConfig(long id, ServerConfig.NewServerConfig newServerConfig) throws DBException {
+    int countMessagesInLastMinute(String serverId);
-        var getServerConfig = """
-                UPDATE server_configs SET system_message = ?, rate_limit = ?, server_id = ? WHERE id = ?
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getServerConfig)
-        ) {
-            pstmt.setString(1, newServerConfig.systemMessage());
-            pstmt.setInt(2, newServerConfig.rateLimit());
-            pstmt.setString(3, newServerConfig.serverId());
-            pstmt.setLong(4, id);
-            int affectedRows = pstmt.executeUpdate();
-            if (affectedRows == 0) {
-                logger.error("No config update for server with id: " + newServerConfig.serverId());
-            }
-        } catch (SQLException e) {
-            throw new DBException("Adding configuration to server with id: " + newServerConfig.serverId(), e);
-        }
-    }
 
-    public void deleteConfig(long id) throws DBException {
+    void addMessage(ServerMessage.NewServerMessage serverMessage);
-        var getServerConfig = """
-                DELETE FROM server_configs WHERE id = ?
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getServerConfig)
-        ) {
-            pstmt.setLong(1, id);
-            int affectedRows = pstmt.executeUpdate();
-            if (affectedRows == 0) {
-                logger.error("No config deleted for server with id: " + id);
-            }
-        } catch (SQLException e) {
-            throw new DBException("Deleting configuration for server with id: " + id, e);
-        }
-    }
 
-    public int countMessagesInLastMinute(String serverId) {
+    long tokensOfLast30Days(String serverId);
-        var getServerConfig = """
-                SELECT count(*) FROM server_messages WHERE server_id = ? AND time <= ? and time >= ?
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getServerConfig)
-        ) {
-            pstmt.setString(1, serverId);
-            var now = Instant.now();
-            pstmt.setTimestamp(2, Timestamp.from(now));
-            pstmt.setTimestamp(3, Timestamp.from(now.minus(1, ChronoUnit.MINUTES)));
-            ResultSet resultSet = pstmt.executeQuery();
-            resultSet.next();
-            return resultSet.getInt(1);
-        } catch (SQLException e) {
-            logger.error("Getting messages for server with id: " + serverId, e);
-        } catch (ResultSetIteratorException e) {
-            logger.error("Iterating over ServerMessages ResultSet for server with id: " + serverId, e);
-            return Integer.MAX_VALUE;
-        }
-        return Integer.MAX_VALUE;
-    }
-
-    public void addMessage(ServerMessage.NewServerMessage serverMessage) {
-        var getServerConfig = """
-                INSERT INTO server_messages (server_id, user_id, tokens) VALUES (?,?,?)
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getServerConfig)
-        ) {
-            pstmt.setString(1, serverMessage.serverId());
-            pstmt.setLong(2, serverMessage.userId());
-            pstmt.setInt(3, serverMessage.tokens());
-            int affectedRows = pstmt.executeUpdate();
-            if (affectedRows == 0) {
-                logger.error("No message added for server with id: " + serverMessage.serverId());
-            }
-        } catch (SQLException e) {
-            logger.error("Adding message to server with id: " + serverMessage.serverId(), e);
-        }
-    }
-
-    public long tokensOfLast30Days(String serverId) {
-        var countTokensOfLast30Days = """
-                SELECT sum(tokens) FROM server_messages WHERE server_id = ? AND time < ? AND time >= ?
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(countTokensOfLast30Days)
-        ) {
-            pstmt.setString(1, serverId);
-            var now = Instant.now();
-            pstmt.setTimestamp(2, Timestamp.from(now));
-            pstmt.setTimestamp(3, Timestamp.from(now.minus(30, ChronoUnit.DAYS)));
-            ResultSet resultSet = pstmt.executeQuery();
-            resultSet.next();
-            return resultSet.getLong(1);
-        } catch (SQLException e) {
-            logger.error("Counting tokens of the last 30 days from server with id: " + serverId, e);
-        }
-        logger.error("No tokens found for server with id: " + serverId);
-        return 0;
-    }
 }

db/src/main/java/de/hhhammer/dchat/db/UserDBService.java

@@ -2,219 +2,28 @@ package de.hhhammer.dchat.db;
 
 import de.hhhammer.dchat.db.models.user.UserConfig;
 import de.hhhammer.dchat.db.models.user.UserMessage;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
-import javax.sql.DataSource;
-import java.sql.*;
-import java.time.Instant;
-import java.time.temporal.ChronoUnit;
 import java.util.List;
 import java.util.Optional;
-import java.util.stream.StreamSupport;
 
-public class UserDBService {
+public interface UserDBService {
-    private static final Logger logger = LoggerFactory.getLogger(UserDBService.class);
+    Optional<UserConfig> getConfig(String userId);
-    private final DataSource dataSource;
 
-    public UserDBService(DataSource dataSource) {
+    Optional<UserConfig> getConfigBy(long id) throws DBException;
-        this.dataSource = dataSource;
-    }
 
-    public Optional<UserConfig> getConfig(String userId) {
+    List<UserConfig> getAllConfigs() throws DBException;
-        var getServerConfig = """
-                SELECT * FROM user_configs WHERE user_id = ?
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getServerConfig)
-        ) {
-            pstmt.setString(1, userId);
-            ResultSet resultSet = pstmt.executeQuery();
-            Iterable<UserConfig> iterable = () -> new ResultSetIterator<>(resultSet, new UserConfig.UserConfigResultSetTransformer());
-            return StreamSupport.stream(iterable.spliterator(), false).findFirst();
-        } catch (SQLException e) {
-            logger.error("Getting configuration for user with id: " + userId, e);
-        } catch (ResultSetIteratorException e) {
-            logger.error("Iterating over ServerConfig ResultSet for user with id: " + userId, e);
-            return Optional.empty();
-        }
-        return Optional.empty();
-    }
 
-    public Optional<UserConfig> getConfigBy(long id) throws DBException {
+    void addConfig(UserConfig.NewUserConfig newUserConfig) throws DBException;
-        var getServerConfig = """
-                SELECT * FROM user_configs WHERE id = ?
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getServerConfig)
-        ) {
-            pstmt.setLong(1, id);
-            ResultSet resultSet = pstmt.executeQuery();
-            Iterable<UserConfig> iterable = () -> new ResultSetIterator<>(resultSet, new UserConfig.UserConfigResultSetTransformer());
-            return StreamSupport.stream(iterable.spliterator(), false).findFirst();
-        } catch (SQLException e) {
-            throw new DBException("Getting configuration id: " + id, e);
-        } catch (ResultSetIteratorException e) {
-            throw new DBException("Iterating over UserConfig ResultSet with id: " + id, e);
-        }
-    }
 
-    public List<UserConfig> getAllConfigs() throws DBException {
+    void updateConfig(long id, UserConfig.NewUserConfig newUserConfig) throws DBException;
-        var getServerConfig = """
-                SELECT * FROM user_configs
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getServerConfig)
-        ) {
-            ResultSet resultSet = pstmt.executeQuery();
-            Iterable<UserConfig> iterable = () -> new ResultSetIterator<>(resultSet, new UserConfig.UserConfigResultSetTransformer());
-            return StreamSupport.stream(iterable.spliterator(), false).toList();
-        } catch (SQLException e) {
-            throw new DBException("Getting all configurations", e);
-        } catch (ResultSetIteratorException e) {
-            throw new DBException("Iterating over all UserConfig ResultSet", e);
-        }
-    }
 
-    public void addConfig(UserConfig.NewUserConfig newUserConfig) throws DBException {
+    void deleteConfig(long id) throws DBException;
-        var getServerConfig = """
-                INSERT INTO user_configs (user_id, system_message, context_length, rate_limit) VALUES (?,?,?,?)
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getServerConfig)
-        ) {
-            pstmt.setString(1, newUserConfig.userId());
-            pstmt.setString(2, newUserConfig.systemMessage());
-            pstmt.setInt(3, newUserConfig.contextLength());
-            pstmt.setInt(4, newUserConfig.rateLimit());
-            int affectedRows = pstmt.executeUpdate();
-            if (affectedRows == 0) {
-                logger.error("No config added for user with id: " + newUserConfig.userId());
-            }
-        } catch (SQLException e) {
-            throw new DBException("Adding configuration for user with id: " + newUserConfig.userId(), e);
-        }
-    }
 
-    public void updateConfig(long id, UserConfig.NewUserConfig newUserConfig) throws DBException {
+    int countMessagesInLastMinute(String userId);
-        var getServerConfig = """
-                UPDATE user_configs SET system_message = ?, context_length = ?, rate_limit = ?, user_id = ? WHERE id = ?
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getServerConfig)
-        ) {
-            pstmt.setString(1, newUserConfig.systemMessage());
-            pstmt.setInt(2, newUserConfig.rateLimit());
-            pstmt.setLong(3, newUserConfig.contextLength());
-            pstmt.setString(4, newUserConfig.userId());
-            pstmt.setLong(5, id);
-            int affectedRows = pstmt.executeUpdate();
-            if (affectedRows == 0) {
-                logger.error("No config update with id: " + id);
-            }
-        } catch (SQLException e) {
-            throw new DBException("Updating configuration with id: " + id, e);
-        }
-    }
 
-    public void deleteConfig(long id) throws DBException {
+    void addMessage(UserMessage.NewUserMessage newUserMessage);
-        var getServerConfig = """
-                DELETE FROM user_configs WHERE id = ?
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getServerConfig)
-        ) {
-            pstmt.setLong(1, id);
-            int affectedRows = pstmt.executeUpdate();
-            if (affectedRows == 0) {
-                logger.error("No config deleted for user with id: " + id);
-            }
-        } catch (SQLException e) {
-            throw new DBException("Deleting configuration with id: " + id, e);
-        }
-    }
 
-    public int countMessagesInLastMinute(String userId) {
+    List<UserMessage> getLastMessages(String userId, int limit);
-        var getServerConfig = """
-                SELECT count(*) FROM user_messages WHERE user_id = ? AND time <= ? and time >= ?
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getServerConfig)
-        ) {
-            pstmt.setString(1, userId);
-            var now = Instant.now();
-            pstmt.setTimestamp(2, Timestamp.from(now));
-            pstmt.setTimestamp(3, Timestamp.from(now.minus(1, ChronoUnit.MINUTES)));
-            ResultSet resultSet = pstmt.executeQuery();
-            resultSet.next();
-            return resultSet.getInt(1);
-        } catch (SQLException e) {
-            logger.error("Getting messages for user with id: " + userId, e);
-        } catch (ResultSetIteratorException e) {
-            logger.error("Iterating over ServerMessages ResultSet for user with id: " + userId, e);
-            return Integer.MAX_VALUE;
-        }
-        return Integer.MAX_VALUE;
-    }
 
-    public void addMessage(UserMessage.NewUserMessage newUserMessage) {
+    long tokensOfLast30Days(String userId);
-        var getServerConfig = """
-                INSERT INTO user_messages (user_id, question, answer, tokens) VALUES (?,?,?,?)
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getServerConfig)
-        ) {
-            pstmt.setString(1, newUserMessage.userId());
-            pstmt.setString(2, newUserMessage.question());
-            pstmt.setString(3, newUserMessage.answer());
-            pstmt.setInt(4, newUserMessage.tokens());
-            int affectedRows = pstmt.executeUpdate();
-            if (affectedRows == 0) {
-                logger.error("No message added for user with id: " + newUserMessage.userId());
-            }
-        } catch (SQLException e) {
-            logger.error("Adding message to user with id: " + newUserMessage.userId(), e);
-        }
-    }
-
-    public List<UserMessage> getLastMessages(String userId, int limit) {
-        var getLastMessages = """
-                SELECT * FROM user_messages WHERE user_id = ? ORDER BY time DESC LIMIT ?
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(getLastMessages)
-        ) {
-            pstmt.setString(1, userId);
-            pstmt.setInt(2, limit);
-            ResultSet resultSet = pstmt.executeQuery();
-            Iterable<UserMessage> iterable = () -> new ResultSetIterator<>(resultSet, new UserMessage.UserMessageResultSetTransformer());
-            return StreamSupport.stream(iterable.spliterator(), false).toList();
-        } catch (SQLException e) {
-            logger.error("Fetching last messages for user whit id: " + userId, e);
-        } catch (ResultSetIteratorException e) {
-            logger.error("Iterating over messages ResultSet from user with id: " + userId, e);
-        }
-        return List.of();
-    }
-
-    public long tokensOfLast30Days(String userId) {
-        var countTokensOfLast30Days = """
-                SELECT sum(tokens) FROM user_messages WHERE user_id = ? AND time < ? AND time >= ?
-                """;
-        try (Connection con = dataSource.getConnection();
-             PreparedStatement pstmt = con.prepareStatement(countTokensOfLast30Days)
-        ) {
-            pstmt.setString(1, userId);
-            var now = Instant.now();
-            pstmt.setTimestamp(2, Timestamp.from(now));
-            pstmt.setTimestamp(3, Timestamp.from(now.minus(30, ChronoUnit.DAYS)));
-            ResultSet resultSet = pstmt.executeQuery();
-            resultSet.next();
-            return resultSet.getLong(1);
-        } catch (SQLException e) {
-            logger.error("Counting tokens of the last 30 days from user with id: " + userId, e);
-        }
-        logger.error("No tokens found for user with id: " + userId);
-        return 0;
-    }
 }

migration/src/main/java/de/hhhammer/dchat/migration/App.java

@@ -6,20 +6,20 @@ import org.slf4j.LoggerFactory;
 /**
  * Hello world!
  */
-public class App {
+public final class App {
     private static final Logger logger = LoggerFactory.getLogger(App.class);
     private static final String DB_MIGRATION_PATH = "db/schema.sql";
 
-    public static void main(String[] args) {
+    public static void main(final String[] args) {
-        String postgresUser = System.getenv("POSTGRES_USER");
+        final String postgresUser = System.getenv("POSTGRES_USER");
-        String postgresPassword = System.getenv("POSTGRES_PASSWORD");
+        final String postgresPassword = System.getenv("POSTGRES_PASSWORD");
-        String postgresUrl = System.getenv("POSTGRES_URL");
+        final String postgresUrl = System.getenv("POSTGRES_URL");
         if (postgresUser == null || postgresPassword == null || postgresUrl == null) {
             logger.error("Missing environment variables: POSTGRES_USER and/or POSTGRES_PASSWORD and/or POSTGRES_URL");
             System.exit(1);
         }
-        var migrationExecutor = new MigrationExecutor(postgresUrl, postgresUser, postgresPassword);
+        final var migrationExecutor = new MigrationExecutor(postgresUrl, postgresUser, postgresPassword);
-        var dbMigrator = new DBMigrator(migrationExecutor, DB_MIGRATION_PATH);
+        final var dbMigrator = new DBMigrator(migrationExecutor, DB_MIGRATION_PATH);
         dbMigrator.run();
     }
 }

migration/src/main/java/de/hhhammer/dchat/migration/DBMigrationException.java

@@ -1,7 +1,7 @@
 package de.hhhammer.dchat.migration;
 
-public class DBMigrationException extends Exception {
+public final class DBMigrationException extends Exception {
-    public DBMigrationException(Throwable cause) {
+    public DBMigrationException(final Throwable cause) {
         super(cause);
     }
 }

migration/src/main/java/de/hhhammer/dchat/migration/DBMigrator.java

@@ -6,12 +6,12 @@ import org.slf4j.LoggerFactory;
 import java.io.IOException;
 import java.io.InputStream;
 
-public class DBMigrator implements Runnable {
+public final class DBMigrator implements Runnable {
     private static final Logger logger = LoggerFactory.getLogger(DBMigrator.class);
     private final MigrationExecutor migrationExecutor;
     private final String resourcePath;
 
-    public DBMigrator(MigrationExecutor migrationExecutor, String resourcePath) {
+    public DBMigrator(final MigrationExecutor migrationExecutor, final String resourcePath) {
         this.migrationExecutor = migrationExecutor;
         this.resourcePath = resourcePath;
     }
@@ -19,8 +19,8 @@ public class DBMigrator implements Runnable {
     @Override
     public void run() {
         logger.info("Starting db migration");
-        ClassLoader classLoader = getClass().getClassLoader();
+        final ClassLoader classLoader = getClass().getClassLoader();
-        try (InputStream inputStream = classLoader.getResourceAsStream(this.resourcePath)) {
+        try (final InputStream inputStream = classLoader.getResourceAsStream(this.resourcePath)) {
             if (inputStream == null) {
                 logger.error("Migration file not found: " + resourcePath);
                 throw new RuntimeException("Migration file not found");

migration/src/main/java/de/hhhammer/dchat/migration/MigrationExecutor.java

@@ -11,24 +11,24 @@ import java.sql.DriverManager;
 import java.sql.SQLException;
 import java.sql.Statement;
 
-public class MigrationExecutor {
+public final class MigrationExecutor {
     private static final Logger logger = LoggerFactory.getLogger(MigrationExecutor.class);
     private final String jdbcConnectionString;
     private final String username;
     private final String password;
 
-    public MigrationExecutor(String jdbcConnectionString, String username, String password) {
+    public MigrationExecutor(final String jdbcConnectionString, final String username, final String password) {
         this.jdbcConnectionString = jdbcConnectionString;
         this.username = username;
         this.password = password;
     }
 
-    public void migrate(InputStream input) throws DBMigrationException {
+    public void migrate(final InputStream input) throws DBMigrationException {
-        try (Connection con = DriverManager
+        try (final Connection con = DriverManager
                 .getConnection(this.jdbcConnectionString, this.username, this.password);
-             Statement stmp = con.createStatement();
+             final Statement stmp = con.createStatement();
         ) {
-            String content = new String(input.readAllBytes(), StandardCharsets.UTF_8);
+            final String content = new String(input.readAllBytes(), StandardCharsets.UTF_8);
             stmp.execute(content);
         } catch (SQLException | IOException e) {
             throw new DBMigrationException(e);

web/pom.xml

@@ -12,10 +12,6 @@
     <version>1.0-SNAPSHOT</version>
     <name>web</name>
 
-    <properties>
-        <node.version>v18.16.0</node.version>
-    </properties>
-
     <dependencies>
         <dependency>
             <groupId>de.hhhammer.dchat</groupId>

web/src/main/java/de/hhhammer/dchat/web/App.java

@@ -2,41 +2,41 @@ package de.hhhammer.dchat.web;
 
 import com.zaxxer.hikari.HikariConfig;
 import com.zaxxer.hikari.HikariDataSource;
-import de.hhhammer.dchat.db.ServerDBService;
+import de.hhhammer.dchat.db.PostgresServerDBService;
-import de.hhhammer.dchat.db.UserDBService;
+import de.hhhammer.dchat.db.PostgresUserDBService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
  * Hello world!
  */
-public class App {
+public final class App {
     private static final Logger logger = LoggerFactory.getLogger(App.class);
 
-    public static void main(String[] args) {
+    public static void main(final String[] args) {
-        String postgresUser = System.getenv("POSTGRES_USER");
+        final String postgresUser = System.getenv("POSTGRES_USER");
-        String postgresPassword = System.getenv("POSTGRES_PASSWORD");
+        final String postgresPassword = System.getenv("POSTGRES_PASSWORD");
-        String postgresUrl = System.getenv("POSTGRES_URL");
+        final String postgresUrl = System.getenv("POSTGRES_URL");
         if (postgresUser == null || postgresPassword == null || postgresUrl == null) {
             logger.error("Missing environment variables: POSTGRES_USER and/or POSTGRES_PASSWORD and/or POSTGRES_URL");
             System.exit(1);
         }
 
-        String apiPortStr = System.getenv("API_PORT") != null ? System.getenv("API_PORT") : "8080";
+        final String apiPortStr = System.getenv("API_PORT") != null ? System.getenv("API_PORT") : "8080";
-        int apiPort = Integer.parseInt(apiPortStr);
+        final int apiPort = Integer.parseInt(apiPortStr);
-        boolean debug = "true".equals(System.getenv("API_DEBUG"));
+        final boolean debug = "true".equals(System.getenv("API_DEBUG"));
 
-        var config = new HikariConfig();
+        final var config = new HikariConfig();
         config.setJdbcUrl(postgresUrl);
         config.setUsername(postgresUser);
         config.setPassword(postgresPassword);
 
-        try (var ds = new HikariDataSource(config)) {
+        try (final var ds = new HikariDataSource(config)) {
-            var serverDBService = new ServerDBService(ds);
+            final var serverDBService = new PostgresServerDBService(ds);
-            var userDBService = new UserDBService(ds);
+            final var userDBService = new PostgresUserDBService(ds);
-            var appConfig = new AppConfig(apiPort, debug);
+            final var appConfig = new AppConfig(apiPort, debug);
 
-            var webApi = new WebAPI(serverDBService, userDBService, appConfig);
+            final var webApi = new WebAPI(serverDBService, userDBService, appConfig);
             webApi.run();
         }
     }

web/src/main/java/de/hhhammer/dchat/web/WebAPI.java

@@ -6,7 +6,6 @@ import de.hhhammer.dchat.web.server.ConfigCrudHandler;
 import de.hhhammer.dchat.web.user.ConfigUserCrudHandler;
 import io.javalin.Javalin;
 import io.javalin.http.HttpStatus;
-import io.javalin.http.staticfiles.Location;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -16,13 +15,13 @@ import java.util.concurrent.ExecutionException;
 import static io.javalin.apibuilder.ApiBuilder.crud;
 import static io.javalin.apibuilder.ApiBuilder.path;
 
-public class WebAPI implements Runnable {
+public final class WebAPI implements Runnable {
     private static final Logger logger = LoggerFactory.getLogger(WebAPI.class);
     private final ServerDBService serverDBService;
     private final UserDBService userDBService;
     private final AppConfig appConfig;
 
-    public WebAPI(ServerDBService serverDBService, UserDBService userDBService, AppConfig appConfig) {
+    public WebAPI(final ServerDBService serverDBService, final UserDBService userDBService, final AppConfig appConfig) {
         this.serverDBService = serverDBService;
         this.userDBService = userDBService;
         this.appConfig = appConfig;
@@ -31,12 +30,12 @@ public class WebAPI implements Runnable {
     @Override
     public void run() {
         logger.info("Starting web application");
-        var app = Javalin.create(config -> {
+        final Javalin app = Javalin.create(config -> {
             if (appConfig.debug()) config.plugins.enableDevLogging();
             config.http.prefer405over404 = true;  // return 405 instead of 404 if path is mapped to different HTTP method
             config.http.defaultContentType = "application/json";
         });
-        var waitForShutdown = new CompletableFuture<Void>();
+        final var waitForShutdown = new CompletableFuture<Void>();
         Runtime.getRuntime().addShutdownHook(new Thread(() -> {
             logger.info("Shutting down web application");
             app.stop();

web/src/main/java/de/hhhammer/dchat/web/server/ConfigCrudHandler.java

@@ -10,18 +10,21 @@ import org.jetbrains.annotations.NotNull;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public class ConfigCrudHandler implements CrudHandler {
+import java.util.List;
+import java.util.Optional;
+
+public final class ConfigCrudHandler implements CrudHandler {
     private static final Logger logger = LoggerFactory.getLogger(ConfigCrudHandler.class);
 
     private final ServerDBService serverDBService;
 
-    public ConfigCrudHandler(ServerDBService serverDBService) {
+    public ConfigCrudHandler(final ServerDBService serverDBService) {
         this.serverDBService = serverDBService;
     }
 
     @Override
-    public void create(@NotNull Context context) {
+    public void create(@NotNull final Context context) {
-        var body = context.bodyAsClass(ServerConfig.NewServerConfig.class);
+        final ServerConfig.NewServerConfig body = context.bodyAsClass(ServerConfig.NewServerConfig.class);
         try {
             this.serverDBService.addConfig(body);
         } catch (DBException e) {
@@ -32,9 +35,10 @@ public class ConfigCrudHandler implements CrudHandler {
     }
 
     @Override
-    public void delete(@NotNull Context context, @NotNull String s) {
+    public void delete(@NotNull final Context context, @NotNull final String s) {
+        final var id = Long.parseLong(s);
         try {
-            this.serverDBService.deleteConfig(Long.parseLong(s));
+            this.serverDBService.deleteConfig(id);
             context.status(HttpStatus.NO_CONTENT);
         } catch (DBException e) {
             logger.error("Deleting configuration with id: " + s, e);
@@ -43,9 +47,9 @@ public class ConfigCrudHandler implements CrudHandler {
     }
 
     @Override
-    public void getAll(@NotNull Context context) {
+    public void getAll(@NotNull final Context context) {
         try {
-            var allowedServers = this.serverDBService.getAllConfigs();
+            final List<ServerConfig> allowedServers = this.serverDBService.getAllConfigs();
             context.json(allowedServers);
         } catch (DBException e) {
             logger.error("Getting all server configs", e);
@@ -54,10 +58,10 @@ public class ConfigCrudHandler implements CrudHandler {
     }
 
     @Override
-    public void getOne(@NotNull Context context, @NotNull String s) {
+    public void getOne(@NotNull final Context context, @NotNull final String s) {
-        var id = Long.parseLong(s);
+        final var id = Long.parseLong(s);
         try {
-            var server = this.serverDBService.getConfigBy(id);
+            final Optional<ServerConfig> server = this.serverDBService.getConfigBy(id);
             if (server.isEmpty()) {
                 context.status(HttpStatus.NOT_FOUND);
                 return;
@@ -70,9 +74,9 @@ public class ConfigCrudHandler implements CrudHandler {
     }
 
     @Override
-    public void update(@NotNull Context context, @NotNull String idString) {
+    public void update(@NotNull final Context context, @NotNull final String idString) {
-        var body = context.bodyAsClass(ServerConfig.NewServerConfig.class);
+        final ServerConfig.NewServerConfig body = context.bodyAsClass(ServerConfig.NewServerConfig.class);
-        var id = Long.parseLong(idString);
+        final var id = Long.parseLong(idString);
 
         try {
             this.serverDBService.updateConfig(id, body);

web/src/main/java/de/hhhammer/dchat/web/user/ConfigUserCrudHandler.java

@@ -10,18 +10,21 @@ import org.jetbrains.annotations.NotNull;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-public class ConfigUserCrudHandler implements CrudHandler {
+import java.util.List;
+import java.util.Optional;
+
+public final class ConfigUserCrudHandler implements CrudHandler {
     private static final Logger logger = LoggerFactory.getLogger(ConfigUserCrudHandler.class);
 
     private final UserDBService userDBService;
 
-    public ConfigUserCrudHandler(UserDBService userDBService) {
+    public ConfigUserCrudHandler(final UserDBService userDBService) {
         this.userDBService = userDBService;
     }
 
     @Override
-    public void create(@NotNull Context context) {
+    public void create(@NotNull final Context context) {
-        var body = context.bodyAsClass(UserConfig.NewUserConfig.class);
+        final UserConfig.NewUserConfig body = context.bodyAsClass(UserConfig.NewUserConfig.class);
         try {
             this.userDBService.addConfig(body);
         } catch (DBException e) {
@@ -33,9 +36,10 @@ public class ConfigUserCrudHandler implements CrudHandler {
     }
 
     @Override
-    public void delete(@NotNull Context context, @NotNull String s) {
+    public void delete(@NotNull final Context context, @NotNull final String s) {
+        final var id = Long.parseLong(s);
         try {
-            this.userDBService.deleteConfig(Long.parseLong(s));
+            this.userDBService.deleteConfig(id);
             context.status(HttpStatus.NO_CONTENT);
         } catch (DBException e) {
             logger.error("Deleting configuration with id: " + s, e);
@@ -44,9 +48,9 @@ public class ConfigUserCrudHandler implements CrudHandler {
     }
 
     @Override
-    public void getAll(@NotNull Context context) {
+    public void getAll(@NotNull final Context context) {
         try {
-            var allowedServers = this.userDBService.getAllConfigs();
+            final List<UserConfig> allowedServers = this.userDBService.getAllConfigs();
             context.json(allowedServers);
         } catch (DBException e) {
             logger.error("Getting all user configs", e);
@@ -55,10 +59,10 @@ public class ConfigUserCrudHandler implements CrudHandler {
     }
 
     @Override
-    public void getOne(@NotNull Context context, @NotNull String s) {
+    public void getOne(@NotNull final Context context, @NotNull final String s) {
-        var id = Long.parseLong(s);
+        final var id = Long.parseLong(s);
         try {
-            var server = this.userDBService.getConfigBy(id);
+            final Optional<UserConfig> server = this.userDBService.getConfigBy(id);
             if (server.isEmpty()) {
                 context.status(HttpStatus.NOT_FOUND);
                 return;
@@ -72,8 +76,8 @@ public class ConfigUserCrudHandler implements CrudHandler {
 
     @Override
     public void update(@NotNull Context context, @NotNull String idString) {
-        var body = context.bodyAsClass(UserConfig.NewUserConfig.class);
+        final UserConfig.NewUserConfig body = context.bodyAsClass(UserConfig.NewUserConfig.class);
-        var id = Long.parseLong(idString);
+        final var id = Long.parseLong(idString);
 
         try {
             this.userDBService.updateConfig(id, body);