Update HttpServer & AuthenticationSystem to use Javalin

build.gradle

@@ -94,6 +94,7 @@ dependencies {
     implementation group:  'com.github.davidmoten', name : 'rtree-multi', version: '0.1'
 
     implementation group: 'io.javalin', name: 'javalin', version: '4.6.4'
+    implementation group: 'com.fasterxml.jackson.core', name: 'jackson-databind', version: '2.13.3'
 
     protobuf files('proto/')
 

src/main/java/emu/grasscutter/auth/AuthenticationSystem.java

@@ -2,8 +2,7 @@ package emu.grasscutter.auth;
 
 import emu.grasscutter.game.Account;
 import emu.grasscutter.server.http.objects.*;
-import express.http.Request;
-import express.http.Response;
+import io.javalin.http.Context;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Getter;
@@ -71,8 +70,7 @@ public interface AuthenticationSystem {
      */
     @Builder @AllArgsConstructor @Getter
     class AuthenticationRequest {
-        private final Request request;
-        @Nullable private final Response response;
+        private final Context context;
 
         @Nullable private final LoginAccountRequestJson passwordRequest;
         @Nullable private final LoginTokenRequestJson tokenRequest;
@@ -82,53 +80,51 @@ public interface AuthenticationSystem {
 
     /**
      * Generates an authentication request from a {@link LoginAccountRequestJson} object.
-     * @param request The Express request.
+     * @param ctx The Javalin context.
      * @param jsonData The JSON data.
      * @return An authentication request.
      */
-    static AuthenticationRequest fromPasswordRequest(Request request, LoginAccountRequestJson jsonData) {
+    static AuthenticationRequest fromPasswordRequest(Context ctx, LoginAccountRequestJson jsonData) {
         return AuthenticationRequest.builder()
-                .request(request)
+                .context(ctx)
                 .passwordRequest(jsonData)
                 .build();
     }
 
     /**
      * Generates an authentication request from a {@link LoginTokenRequestJson} object.
-     * @param request The Express request.
+     * @param ctx The Javalin context.
      * @param jsonData The JSON data.
      * @return An authentication request.
      */
-    static AuthenticationRequest fromTokenRequest(Request request, LoginTokenRequestJson jsonData) {
+    static AuthenticationRequest fromTokenRequest(Context ctx, LoginTokenRequestJson jsonData) {
         return AuthenticationRequest.builder()
-                .request(request)
+                .context(ctx)
                 .tokenRequest(jsonData)
                 .build();
     }
 
     /**
      * Generates an authentication request from a {@link ComboTokenReqJson} object.
-     * @param request The Express request.
+     * @param ctx The Javalin context.
      * @param jsonData The JSON data.
      * @return An authentication request.
      */
-    static AuthenticationRequest fromComboTokenRequest(Request request, ComboTokenReqJson jsonData, 
+    static AuthenticationRequest fromComboTokenRequest(Context ctx, ComboTokenReqJson jsonData,
                                                        ComboTokenReqJson.LoginTokenData tokenData) {
         return AuthenticationRequest.builder()
-                .request(request)
+                .context(ctx)
                 .sessionKeyRequest(jsonData)
                 .sessionKeyData(tokenData)
                 .build();
     }
 
     /**
-     * Generates an authentication request from a {@link Response} object.
-     * @param request The Express request.
-     * @param response the Express response.
+     * Generates an authentication request from a {@link Context} object.
+     * @param ctx The Javalin context.
      * @return An authentication request.
      */
-    static AuthenticationRequest fromExternalRequest(Request request, Response response) {
-        return AuthenticationRequest.builder().request(request)
-                .response(response).build();
+    static AuthenticationRequest fromExternalRequest(Context ctx) {
+        return AuthenticationRequest.builder().context(ctx).build();
     }
 }

src/main/java/emu/grasscutter/auth/DefaultAuthenticators.java

@@ -36,7 +36,7 @@ public final class DefaultAuthenticators {
             int playerCount = Grasscutter.getGameServer().getPlayers().size();
 
             boolean successfulLogin = false;
-            String address = request.getRequest().ip();
+            String address = request.getContext().ip();
             String responseMessage = translate("messages.dispatch.account.username_error");
             String loggerMessage = "";
 
@@ -99,7 +99,7 @@ public final class DefaultAuthenticators {
             int playerCount = Grasscutter.getGameServer().getPlayers().size();
 
             boolean successfulLogin = false;
-            String address = request.getRequest().ip();
+            String address = request.getContext().ip();
             String responseMessage = translate("messages.dispatch.account.username_error");
             String loggerMessage = "";
             String decryptedPassword = "";
@@ -205,7 +205,7 @@ public final class DefaultAuthenticators {
             assert requestData != null;
 
             boolean successfulLogin;
-            String address = request.getRequest().ip();
+            String address = request.getContext().ip();
             String loggerMessage;
             int playerCount = Grasscutter.getGameServer().getPlayers().size();
 
@@ -263,7 +263,7 @@ public final class DefaultAuthenticators {
             assert loginData != null;
 
             boolean successfulLogin;
-            String address = request.getRequest().ip();
+            String address = request.getContext().ip();
             String loggerMessage;
             int playerCount = Grasscutter.getGameServer().getPlayers().size();
 
@@ -309,43 +309,37 @@ public final class DefaultAuthenticators {
     public static class ExternalAuthentication implements ExternalAuthenticator {
         @Override
         public void handleLogin(AuthenticationRequest request) {
-            assert request.getResponse() != null;
-            request.getResponse().send("Authentication is not available with the default authentication method.");
+            request.getContext().result("Authentication is not available with the default authentication method.");
         }
 
         @Override
         public void handleAccountCreation(AuthenticationRequest request) {
-            assert request.getResponse() != null;
-            request.getResponse().send("Authentication is not available with the default authentication method.");
+            request.getContext().result("Authentication is not available with the default authentication method.");
         }
 
         @Override
         public void handlePasswordReset(AuthenticationRequest request) {
-            assert request.getResponse() != null;
-            request.getResponse().send("Authentication is not available with the default authentication method.");
+            request.getContext().result("Authentication is not available with the default authentication method.");
         }
     }
 
     /**
-     * Handles authentication requests from OAuth sources.
+     * Handles authentication requests from OAuth sources.Zenlith
      */
     public static class OAuthAuthentication implements OAuthAuthenticator {
         @Override
         public void handleLogin(AuthenticationRequest request) {
-            assert request.getResponse() != null;
-            request.getResponse().send("Authentication is not available with the default authentication method.");
+            request.getContext().result("Authentication is not available with the default authentication method.");
         }
 
         @Override
         public void handleRedirection(AuthenticationRequest request, ClientType type) {
-            assert request.getResponse() != null;
-            request.getResponse().send("Authentication is not available with the default authentication method.");
+            request.getContext().result("Authentication is not available with the default authentication method.");
         }
 
         @Override
         public void handleTokenProcess(AuthenticationRequest request) {
-            assert request.getResponse() != null;
-            request.getResponse().send("Authentication is not available with the default authentication method.");
+            request.getContext().result("Authentication is not available with the default authentication method.");
         }
     }
 }

src/main/java/emu/grasscutter/server/http/HttpServer.java

@@ -3,9 +3,9 @@ package emu.grasscutter.server.http;
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.Grasscutter.ServerDebugMode;
 import emu.grasscutter.utils.FileUtils;
-import express.Express;
-import express.http.MediaType;
+import emu.grasscutter.utils.HttpUtils;
 import io.javalin.Javalin;
+import io.javalin.core.util.JavalinLogger;
 import org.eclipse.jetty.server.Server;
 import org.eclipse.jetty.server.ServerConnector;
 import org.eclipse.jetty.util.ssl.SslContextFactory;
@@ -21,14 +21,14 @@ import static emu.grasscutter.utils.Language.translate;
  * (including dispatch, announcements, gacha, etc.)
  */
 public final class HttpServer {
-    private final Express express;
+    private final Javalin javalin;
 
     /**
-     * Configures the Express application.
+     * Configures the Javalin application.
      */
     public HttpServer() {
-        this.express = new Express(config -> {
-            // Set the Express HTTP server.
+        this.javalin = Javalin.create(config -> {
+            // Set the Javalin HTTP server.
             config.server(HttpServer::createServer);
 
             // Configure encryption/HTTPS/SSL.
@@ -46,8 +46,7 @@ public final class HttpServer {
             if (DISPATCH_INFO.logRequests == ServerDebugMode.ALL)
                 config.enableDevLogging();
 
-            // Disable compression on static files.
-            config.precompressStaticFiles = false;
+            // Static files should be added like this https://javalin.io/documentation#static-files
         });
     }
 
@@ -100,7 +99,7 @@ public final class HttpServer {
      * @return A Javalin instance.
      */
     public Javalin getHandle() {
-        return this.express.raw();
+        return this.javalin;
     }
 
     /**
@@ -118,7 +117,7 @@ public final class HttpServer {
         try { // Create a router instance & apply routes.
             var constructor = router.getDeclaredConstructor(types); // Get the constructor.
             var routerInstance = constructor.newInstance(args); // Create instance.
-            routerInstance.applyRoutes(this.express, this.getHandle()); // Apply routes.
+            routerInstance.applyRoutes(this.javalin); // Apply routes.
         } catch (Exception exception) {
             Grasscutter.getLogger().warn(translate("messages.dispatch.router_error"), exception);
         } return this;
@@ -131,24 +130,24 @@ public final class HttpServer {
     public void start() throws UnsupportedEncodingException {
         // Attempt to start the HTTP server.
         if (HTTP_INFO.bindAddress.equals("")) {
-            this.express.listen(HTTP_INFO.bindPort);
+            this.javalin.start(HTTP_INFO.bindPort);
         }else {
-            this.express.listen(HTTP_INFO.bindAddress, HTTP_INFO.bindPort);
+            this.javalin.start(HTTP_INFO.bindAddress, HTTP_INFO.bindPort);
         }
 
         // Log bind information.
-        Grasscutter.getLogger().info(translate("messages.dispatch.address_bind", HTTP_INFO.accessAddress, this.express.raw().port()));
+        Grasscutter.getLogger().info(translate("messages.dispatch.address_bind", HTTP_INFO.accessAddress, this.javalin.port()));
     }
 
     /**
      * Handles the '/' (index) endpoint on the Express application.
      */
     public static class DefaultRequestRouter implements Router {
-        @Override public void applyRoutes(Express express, Javalin handle) {
-            express.get("/", (request, response) -> {
+        @Override public void applyRoutes(Javalin javalin) {
+            javalin.get("/", ctx -> {
                 File file = new File(HTTP_STATIC_FILES.indexFile);
                 if (!file.exists())
-                    response.send("""
+                    ctx.result("""
                             <!DOCTYPE html>
                             <html>
                                 <head>
@@ -159,9 +158,8 @@ public final class HttpServer {
                             """.formatted(translate("messages.status.welcome")));
                 else {
                     final var filePath = file.getPath();
-                    final MediaType fromExtension = MediaType.getByExtension(filePath.substring(filePath.lastIndexOf(".") + 1));
-                    response.type((fromExtension != null) ? fromExtension.getMIME() : "text/plain")
-                            .send(FileUtils.read(filePath));
+                    final HttpUtils.MediaType fromExtension = HttpUtils.MediaType.getByExtension(filePath.substring(filePath.lastIndexOf(".") + 1));
+                    ctx.contentType((fromExtension != null) ? fromExtension.getMIME() : "text/plain").result(FileUtils.read(filePath));
                 }
             });
         }
@@ -171,8 +169,8 @@ public final class HttpServer {
      * Handles unhandled endpoints on the Express application.
      */
     public static class UnhandledRequestRouter implements Router {
-        @Override public void applyRoutes(Express express, Javalin handle) {
-            handle.error(404, context -> {
+        @Override public void applyRoutes(Javalin javalin) {
+            javalin.error(404, context -> {
                 if (DISPATCH_INFO.logRequests == ServerDebugMode.MISSING)
                     Grasscutter.getLogger().info(translate("messages.dispatch.unhandled_request_error", context.method(), context.url()));
                 context.contentType("text/html");
@@ -193,7 +191,7 @@ public final class HttpServer {
                         """);
                 else {
                     final var filePath = file.getPath();
-                    final MediaType fromExtension = MediaType.getByExtension(filePath.substring(filePath.lastIndexOf(".") + 1));
+                    final HttpUtils.MediaType fromExtension = HttpUtils.MediaType.getByExtension(filePath.substring(filePath.lastIndexOf(".") + 1));
                     context.contentType((fromExtension != null) ? fromExtension.getMIME() : "text/plain")
                             .result(FileUtils.read(filePath));
                 }

src/main/java/emu/grasscutter/server/http/Router.java

 package emu.grasscutter.server.http;
 
-import express.Express;
 import io.javalin.Javalin;
 
 /**
- * Defines routes for an {@link Express} instance.
+ * Defines routes for an {@link Javalin} instance.
  */
 public interface Router {
 
     /**
      * Called when the router is initialized by Express.
-     * @param express An Express instance.
+     * @param javalin A Javalin instance.
      */
-    void applyRoutes(Express express, Javalin handle);
+    void applyRoutes(Javalin javalin);
 }

src/main/java/emu/grasscutter/server/http/dispatch/DispatchHandler.java

@@ -2,16 +2,13 @@ package emu.grasscutter.server.http.dispatch;
 
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.auth.AuthenticationSystem;
-import emu.grasscutter.auth.OAuthAuthenticator;
 import emu.grasscutter.auth.OAuthAuthenticator.ClientType;
 import emu.grasscutter.server.http.Router;
 import emu.grasscutter.server.http.objects.*;
 import emu.grasscutter.server.http.objects.ComboTokenReqJson.LoginTokenData;
 import emu.grasscutter.utils.JsonUtils;
-import express.Express;
-import express.http.Request;
-import express.http.Response;
 import io.javalin.Javalin;
+import io.javalin.http.Context;
 
 import static emu.grasscutter.utils.Language.translate;
 
@@ -19,40 +16,40 @@ import static emu.grasscutter.utils.Language.translate;
  * Handles requests related to authentication. (aka dispatch)
  */
 public final class DispatchHandler implements Router {
-    @Override public void applyRoutes(Express express, Javalin handle) {
+    @Override public void applyRoutes(Javalin javalin) {
         // Username & Password login (from client).
-        express.post("/hk4e_global/mdk/shield/api/login", DispatchHandler::clientLogin);
+        javalin.post("/hk4e_global/mdk/shield/api/login", DispatchHandler::clientLogin);
         // Cached token login (from registry).
-        express.post("/hk4e_global/mdk/shield/api/verify", DispatchHandler::tokenLogin);
+        javalin.post("/hk4e_global/mdk/shield/api/verify", DispatchHandler::tokenLogin);
         // Combo token login (from session key).
-        express.post("/hk4e_global/combo/granter/login/v2/login", DispatchHandler::sessionKeyLogin);
+        javalin.post("/hk4e_global/combo/granter/login/v2/login", DispatchHandler::sessionKeyLogin);
 
         // External login (from other clients).
-        express.get("/authentication/type", (request, response) -> response.send(Grasscutter.getAuthenticationSystem().getClass().getSimpleName()));
-        express.post("/authentication/login", (request, response) -> Grasscutter.getAuthenticationSystem().getExternalAuthenticator()
-                .handleLogin(AuthenticationSystem.fromExternalRequest(request, response)));
-        express.post("/authentication/register", (request, response) -> Grasscutter.getAuthenticationSystem().getExternalAuthenticator()
-                .handleAccountCreation(AuthenticationSystem.fromExternalRequest(request, response)));
-        express.post("/authentication/change_password", (request, response) -> Grasscutter.getAuthenticationSystem().getExternalAuthenticator()
-                .handlePasswordReset(AuthenticationSystem.fromExternalRequest(request, response)));
+        javalin.get("/authentication/type", ctx -> ctx.result(Grasscutter.getAuthenticationSystem().getClass().getSimpleName()));
+        javalin.post("/authentication/login", ctx -> Grasscutter.getAuthenticationSystem().getExternalAuthenticator()
+                .handleLogin(AuthenticationSystem.fromExternalRequest(ctx)));
+        javalin.post("/authentication/register", ctx -> Grasscutter.getAuthenticationSystem().getExternalAuthenticator()
+                .handleAccountCreation(AuthenticationSystem.fromExternalRequest(ctx)));
+        javalin.post("/authentication/change_password", ctx -> Grasscutter.getAuthenticationSystem().getExternalAuthenticator()
+                .handlePasswordReset(AuthenticationSystem.fromExternalRequest(ctx)));
 
         // External login (from OAuth2).
-        express.post("/hk4e_global/mdk/shield/api/loginByThirdparty", (request, response) -> Grasscutter.getAuthenticationSystem().getOAuthAuthenticator()
-                .handleLogin(AuthenticationSystem.fromExternalRequest(request, response)));
-        express.get("/authentication/openid/redirect", (request, response) -> Grasscutter.getAuthenticationSystem().getOAuthAuthenticator()
-                .handleTokenProcess(AuthenticationSystem.fromExternalRequest(request, response)));
-        express.get("/Api/twitter_login", (request, response) -> Grasscutter.getAuthenticationSystem().getOAuthAuthenticator()
-                .handleRedirection(AuthenticationSystem.fromExternalRequest(request, response), ClientType.DESKTOP));
-        express.get("/sdkTwitterLogin.html", (request, response) -> Grasscutter.getAuthenticationSystem().getOAuthAuthenticator()
-                .handleRedirection(AuthenticationSystem.fromExternalRequest(request, response), ClientType.MOBILE));
+        javalin.post("/hk4e_global/mdk/shield/api/loginByThirdparty", ctx -> Grasscutter.getAuthenticationSystem().getOAuthAuthenticator()
+                .handleLogin(AuthenticationSystem.fromExternalRequest(ctx)));
+        javalin.get("/authentication/openid/redirect", ctx -> Grasscutter.getAuthenticationSystem().getOAuthAuthenticator()
+                .handleTokenProcess(AuthenticationSystem.fromExternalRequest(ctx)));
+        javalin.get("/Api/twitter_login", ctx -> Grasscutter.getAuthenticationSystem().getOAuthAuthenticator()
+                .handleRedirection(AuthenticationSystem.fromExternalRequest(ctx), ClientType.DESKTOP));
+        javalin.get("/sdkTwitterLogin.html", ctx -> Grasscutter.getAuthenticationSystem().getOAuthAuthenticator()
+                .handleRedirection(AuthenticationSystem.fromExternalRequest(ctx), ClientType.MOBILE));
     }
 
     /**
      * @route /hk4e_global/mdk/shield/api/login
      */
-    private static void clientLogin(Request request, Response response) {
+    private static void clientLogin(Context ctx) {
         // Parse body data.
-        String rawBodyData = request.ctx().body();
+        String rawBodyData = ctx.body();
         var bodyData = JsonUtils.decode(rawBodyData, LoginAccountRequestJson.class);
 
         // Validate body data.
@@ -62,20 +59,20 @@ public final class DispatchHandler implements Router {
         // Pass data to authentication handler.
         var responseData = Grasscutter.getAuthenticationSystem()
                 .getPasswordAuthenticator()
-                .authenticate(AuthenticationSystem.fromPasswordRequest(request, bodyData));
+                .authenticate(AuthenticationSystem.fromPasswordRequest(ctx, bodyData));
         // Send response.
-        response.send(responseData);
+        ctx.json(responseData);
 
         // Log to console.
-        Grasscutter.getLogger().info(translate("messages.dispatch.account.login_attempt", request.ip()));
+        Grasscutter.getLogger().info(translate("messages.dispatch.account.login_attempt", ctx.ip()));
     }
 
     /**
      * @route /hk4e_global/mdk/shield/api/verify
      */
-    private static void tokenLogin(Request request, Response response) {
+    private static void tokenLogin(Context ctx) {
         // Parse body data.
-        String rawBodyData = request.ctx().body();
+        String rawBodyData = ctx.body();
         var bodyData = JsonUtils.decode(rawBodyData, LoginTokenRequestJson.class);
 
         // Validate body data.
@@ -85,20 +82,20 @@ public final class DispatchHandler implements Router {
         // Pass data to authentication handler.
         var responseData = Grasscutter.getAuthenticationSystem()
                 .getTokenAuthenticator()
-                .authenticate(AuthenticationSystem.fromTokenRequest(request, bodyData));
+                .authenticate(AuthenticationSystem.fromTokenRequest(ctx, bodyData));
         // Send response.
-        response.send(responseData);
+        ctx.json(responseData);
 
         // Log to console.
-        Grasscutter.getLogger().info(translate("messages.dispatch.account.login_attempt", request.ip()));
+        Grasscutter.getLogger().info(translate("messages.dispatch.account.login_attempt", ctx.ip()));
     }
 
     /**
      * @route /hk4e_global/combo/granter/login/v2/login
      */
-    private static void sessionKeyLogin(Request request, Response response) {
+    private static void sessionKeyLogin(Context ctx) {
         // Parse body data.
-        String rawBodyData = request.ctx().body();
+        String rawBodyData = ctx.body();
         var bodyData = JsonUtils.decode(rawBodyData, ComboTokenReqJson.class);
 
         // Validate body data.
@@ -111,11 +108,11 @@ public final class DispatchHandler implements Router {
         // Pass data to authentication handler.
         var responseData = Grasscutter.getAuthenticationSystem()
                 .getSessionKeyAuthenticator()
-                .authenticate(AuthenticationSystem.fromComboTokenRequest(request, bodyData, tokenData));
+                .authenticate(AuthenticationSystem.fromComboTokenRequest(ctx, bodyData, tokenData));
         // Send response.
-        response.send(responseData);
+        ctx.json(responseData);
 
         // Log to console.
-        Grasscutter.getLogger().info(translate("messages.dispatch.account.login_attempt", request.ip()));
+        Grasscutter.getLogger().info(translate("messages.dispatch.account.login_attempt", ctx.ip()));
     }
 }

src/main/java/emu/grasscutter/server/http/dispatch/RegionHandler.java

@@ -11,20 +11,12 @@ import emu.grasscutter.server.event.dispatch.QueryCurrentRegionEvent;
 import emu.grasscutter.server.http.Router;
 import emu.grasscutter.server.http.objects.QueryCurRegionRspJson;
 import emu.grasscutter.utils.Crypto;
-import emu.grasscutter.utils.FileUtils;
 import emu.grasscutter.utils.Utils;
-import express.Express;
-import express.http.Request;
-import express.http.Response;
 import io.javalin.Javalin;
+import io.javalin.http.Context;
 
 import javax.crypto.Cipher;
 import java.io.ByteArrayOutputStream;
-import java.security.KeyFactory;
-import java.security.PrivateKey;
-import java.security.PublicKey;
-import java.security.spec.PKCS8EncodedKeySpec;
-import java.security.spec.X509EncodedKeySpec;
 import java.util.*;
 import java.util.concurrent.ConcurrentHashMap;
 import java.security.Signature;
@@ -107,36 +99,36 @@ public final class RegionHandler implements Router {
         regionListResponse = Utils.base64Encode(updatedRegionList.toByteString().toByteArray());
     }
 
-    @Override public void applyRoutes(Express express, Javalin handle) {
-        express.get("/query_region_list", RegionHandler::queryRegionList);
-        express.get("/query_cur_region/:region", RegionHandler::queryCurrentRegion );
+    @Override public void applyRoutes(Javalin javalin) {
+        javalin.get("/query_region_list", RegionHandler::queryRegionList);
+        javalin.get("/query_cur_region/{region}", RegionHandler::queryCurrentRegion );
     }
 
     /**
      * @route /query_region_list
      */
-    private static void queryRegionList(Request request, Response response) {
+    private static void queryRegionList(Context ctx) {
         // Invoke event.
         QueryAllRegionsEvent event = new QueryAllRegionsEvent(regionListResponse); event.call();
         // Respond with event result.
-        response.send(event.getRegionList());
+        ctx.result(event.getRegionList());
 
         // Log to console.
-        Grasscutter.getLogger().info(String.format("[Dispatch] Client %s request: query_region_list", request.ip()));
+        Grasscutter.getLogger().info(String.format("[Dispatch] Client %s request: query_region_list", ctx.ip()));
     }
 
     /**
-     * @route /query_cur_region/:region
+     * @route /query_cur_region/{region}
      */
-    private static void queryCurrentRegion(Request request, Response response) {
+    private static void queryCurrentRegion(Context ctx) {
         // Get region to query.
-        String regionName = request.params("region");
-        String versionName = request.query("version");
+        String regionName = ctx.pathParam("region");
+        String versionName = ctx.queryParam("version");
         var region = regions.get(regionName);
 
         // Get region data.
         String regionData = "CAESGE5vdCBGb3VuZCB2ZXJzaW9uIGNvbmZpZw==";
-        if (request.query().values().size() > 0) {
+        if (ctx.queryParamMap().values().size() > 0) {
             if (region != null)
                 regionData = region.getBase64();
         }
@@ -150,18 +142,18 @@ public final class RegionHandler implements Router {
             try {
                 QueryCurrentRegionEvent event = new QueryCurrentRegionEvent(regionData); event.call();
 
-                if (request.query("dispatchSeed") == null) {
+                if (ctx.queryParam("dispatchSeed") == null) {
                     // More love for UA Patch players
                     var rsp = new QueryCurRegionRspJson();
 
                     rsp.content = event.getRegionInfo();
                     rsp.sign = "TW9yZSBsb3ZlIGZvciBVQSBQYXRjaCBwbGF5ZXJz";
 
-                    response.send(rsp);
+                    ctx.json(rsp);
                     return;
                 }
 
-                String key_id = request.query("key_id");
+                String key_id = ctx.queryParam("key_id");
                 Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
                 cipher.init(Cipher.ENCRYPT_MODE, key_id.equals("3") ? Crypto.CUR_OS_ENCRYPT_KEY : Crypto.CUR_CN_ENCRYPT_KEY);
                 var regionInfo = Utils.base64Decode(event.getRegionInfo());
@@ -189,7 +181,7 @@ public final class RegionHandler implements Router {
                 rsp.content = Utils.base64Encode(encryptedRegionInfoStream.toByteArray());
                 rsp.sign = Utils.base64Encode(privateSignature.sign());
 
-                response.send(rsp);
+                ctx.json(rsp);
             }
             catch (Exception e) {
                 Grasscutter.getLogger().error("An error occurred while handling query_cur_region.", e);
@@ -199,10 +191,10 @@ public final class RegionHandler implements Router {
             // Invoke event.
             QueryCurrentRegionEvent event = new QueryCurrentRegionEvent(regionData); event.call();
             // Respond with event result.
-            response.send(event.getRegionInfo());
+            ctx.result(event.getRegionInfo());
         }
         // Log to console.
-        Grasscutter.getLogger().info(String.format("Client %s request: query_cur_region/%s", request.ip(), regionName));
+        Grasscutter.getLogger().info(String.format("Client %s request: query_cur_region/%s", ctx.ip(), regionName));
     }
 
     /**

src/main/java/emu/grasscutter/server/http/documentation/DocumentationHandler.java

 package emu.grasscutter.server.http.documentation;
 
-import express.http.Request;
-import express.http.Response;
+import io.javalin.http.Context;
 
 interface DocumentationHandler {
 
-    void handle(Request request, Response response);
+    void handle(Context ctx);
 }

src/main/java/emu/grasscutter/server/http/documentation/DocumentationServerHandler.java

 package emu.grasscutter.server.http.documentation;
 
 import emu.grasscutter.server.http.Router;
-import express.Express;
 import io.javalin.Javalin;
+import io.javalin.http.Context;
 
 public final class DocumentationServerHandler implements Router {
 
     @Override
-    public void applyRoutes(Express express, Javalin handle) {
+    public void applyRoutes(Javalin javalin) {
         final RootRequestHandler root = new RootRequestHandler();
         final HandbookRequestHandler handbook = new HandbookRequestHandler();
         final GachaMappingRequestHandler gachaMapping = new GachaMappingRequestHandler();
 
-        express.get("/documentation/handbook", handbook::handle);
-        express.get("/documentation/gachamapping", gachaMapping::handle);
-        express.get("/documentation", root::handle);
+        // TODO: Removal
+        // TODO: Forward /documentation requests to https://grasscutter.io/wiki
+        javalin.get("/documentation/handbook", handbook::handle);
+        javalin.get("/documentation/gachamapping", gachaMapping::handle);
+        javalin.get("/documentation", root::handle);
     }
 }

src/main/java/emu/grasscutter/server/http/documentation/GachaMappingRequestHandler.java

 package emu.grasscutter.server.http.documentation;
 
 import emu.grasscutter.tools.Tools;
+import emu.grasscutter.utils.HttpUtils;
 import emu.grasscutter.utils.Language;
-import express.http.Request;
-import express.http.Response;
+import io.javalin.http.Context;
 
 import static emu.grasscutter.config.Configuration.DOCUMENT_LANGUAGE;
 
@@ -17,10 +17,8 @@ final class GachaMappingRequestHandler implements DocumentationHandler {
     }
 
     @Override
-    public void handle(Request request, Response response) {
+    public void handle(Context ctx) {
         final int langIdx = Language.TextStrings.MAP_LANGUAGES.getOrDefault(DOCUMENT_LANGUAGE, 0);  // TODO: This should really be based off the client language somehow
-        response.set("Content-Type", "application/json")
-                .ctx()
-                .result(gachaJsons.get(langIdx));
+        ctx.contentType(HttpUtils.MediaType._json.getMIME()).result(gachaJsons.get(langIdx));
     }
 }

src/main/java/emu/grasscutter/server/http/documentation/HandbookRequestHandler.java

@@ -10,10 +10,10 @@ import emu.grasscutter.data.excels.ItemData;
 import emu.grasscutter.data.excels.MonsterData;
 import emu.grasscutter.data.excels.SceneData;
 import emu.grasscutter.utils.FileUtils;
+import emu.grasscutter.utils.HttpUtils;
 import emu.grasscutter.utils.Language;
 import emu.grasscutter.utils.Utils;
-import express.http.Request;
-import express.http.Response;
+import io.javalin.http.Context;
 import it.unimi.dsi.fastutil.ints.Int2ObjectMap;
 import java.io.File;
 import java.nio.charset.StandardCharsets;
@@ -36,12 +36,13 @@ final class HandbookRequestHandler implements DocumentationHandler {
     }
 
     @Override
-    public void handle(Request request, Response response) {
+    public void handle(Context ctx) {
         final int langIdx = Language.TextStrings.MAP_LANGUAGES.getOrDefault(DOCUMENT_LANGUAGE, 0);  // TODO: This should really be based off the client language somehow
         if (template == null) {
-            response.status(500);
+            ctx.status(500);
         } else {
-            response.send(handbookHtmls.get(langIdx));
+            ctx.contentType(HttpUtils.MediaType._html.getMIME());
+            ctx.result(handbookHtmls.get(langIdx));
         }
     }
 

src/main/java/emu/grasscutter/server/http/documentation/RootRequestHandler.java

@@ -4,11 +4,11 @@ import static emu.grasscutter.config.Configuration.DATA;
 import static emu.grasscutter.utils.Language.translate;
 
 import emu.grasscutter.Grasscutter;
-import emu.grasscutter.data.ResourceLoader;
 import emu.grasscutter.utils.FileUtils;
+import emu.grasscutter.utils.HttpUtils;
 import emu.grasscutter.utils.Utils;
-import express.http.Request;
-import express.http.Response;
+import io.javalin.http.Context;
+
 import java.io.File;
 import java.nio.charset.StandardCharsets;
 
@@ -27,15 +27,16 @@ final class RootRequestHandler implements DocumentationHandler {
     }
 
     @Override
-    public void handle(Request request, Response response) {
+    public void handle(Context ctx) {
         if (template == null) {
-            response.status(500);
+            ctx.status(500);
             return;
         }
 
         String content = template.replace("{{TITLE}}", translate("documentation.index.title"))
                 .replace("{{ITEM_HANDBOOK}}", translate("documentation.index.handbook"))
                 .replace("{{ITEM_GACHA_MAPPING}}", translate("documentation.index.gacha_mapping"));
-        response.send(content);
+        ctx.contentType(HttpUtils.MediaType._html.getMIME());
+        ctx.result(content);
     }
 }

src/main/java/emu/grasscutter/server/http/handlers/AnnouncementsHandler.java

@@ -5,44 +5,39 @@ import emu.grasscutter.data.DataLoader;
 import emu.grasscutter.server.http.objects.HttpJsonResponse;
 import emu.grasscutter.server.http.Router;
 import emu.grasscutter.utils.FileUtils;
+import emu.grasscutter.utils.HttpUtils;
 import emu.grasscutter.utils.Utils;
-import express.Express;
-import express.http.MediaType;
-import express.http.Request;
-import express.http.Response;
 import io.javalin.Javalin;
+import io.javalin.http.Context;
 
 import static emu.grasscutter.config.Configuration.*;
 
-import java.io.File;
-import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
-import java.nio.charset.StandardCharsets;
 import java.util.Objects;
 
 /**
  * Handles requests related to the announcements page.
  */
 public final class AnnouncementsHandler implements Router {
-    @Override public void applyRoutes(Express express, Javalin handle) {
+    @Override public void applyRoutes(Javalin javalin) {
         // hk4e-api-os.hoyoverse.com
-        express.all("/common/hk4e_global/announcement/api/getAlertPic", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"total\":0,\"list\":[]}}"));
+        HttpUtils.allRoutes(javalin, "/common/hk4e_global/announcement/api/getAlertPic", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"total\":0,\"list\":[]}}"));
         // hk4e-api-os.hoyoverse.com
-        express.all("/common/hk4e_global/announcement/api/getAlertAnn", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"alert\":false,\"alert_id\":0,\"remind\":true}}"));
+        HttpUtils.allRoutes(javalin,"/common/hk4e_global/announcement/api/getAlertAnn", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"alert\":false,\"alert_id\":0,\"remind\":true}}"));
         // hk4e-api-os.hoyoverse.com
-        express.all("/common/hk4e_global/announcement/api/getAnnList", AnnouncementsHandler::getAnnouncement);
+        HttpUtils.allRoutes(javalin,"/common/hk4e_global/announcement/api/getAnnList", AnnouncementsHandler::getAnnouncement);
         // hk4e-api-os-static.hoyoverse.com
-        express.all("/common/hk4e_global/announcement/api/getAnnContent", AnnouncementsHandler::getAnnouncement);
+        HttpUtils.allRoutes(javalin,"/common/hk4e_global/announcement/api/getAnnContent", AnnouncementsHandler::getAnnouncement);
         // hk4e-sdk-os.hoyoverse.com
-        express.all("/hk4e_global/mdk/shopwindow/shopwindow/listPriceTier", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"suggest_currency\":\"USD\",\"tiers\":[]}}"));
+        HttpUtils.allRoutes(javalin,"/hk4e_global/mdk/shopwindow/shopwindow/listPriceTier", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"suggest_currency\":\"USD\",\"tiers\":[]}}"));
 
-        express.get("/hk4e/announcement/*", AnnouncementsHandler::getPageResources);
+        javalin.get("/hk4e/announcement/*", AnnouncementsHandler::getPageResources);
     }
 
-    private static void getAnnouncement(Request request, Response response) {
+    private static void getAnnouncement(Context ctx) {
         String data = "";
-        if (Objects.equals(request.baseUrl(), "/common/hk4e_global/announcement/api/getAnnContent")) {
+        if (Objects.equals(ctx.endpointHandlerPath(), "/common/hk4e_global/announcement/api/getAnnContent")) {
             try {
                 data = FileUtils.readToString(DataLoader.load("GameAnnouncement.json"));
             } catch (Exception e) {
@@ -50,7 +45,7 @@ public final class AnnouncementsHandler implements Router {
                     Grasscutter.getLogger().info("Unable to read file 'GameAnnouncementList.json'. \n" + e);
                 }
             }
-        } else if (Objects.equals(request.baseUrl(), "/common/hk4e_global/announcement/api/getAnnList")) {
+        } else if (Objects.equals(ctx.endpointHandlerPath(), "/common/hk4e_global/announcement/api/getAnnList")) {
             try {
                 data = FileUtils.readToString(DataLoader.load("GameAnnouncementList.json"));
             } catch (Exception e) {
@@ -59,11 +54,11 @@ public final class AnnouncementsHandler implements Router {
                 }
             }
         } else {
-            response.send("{\"retcode\":404,\"message\":\"Unknown request path\"}");
+            ctx.result("{\"retcode\":404,\"message\":\"Unknown request path\"}");
         }
 
         if (data.isEmpty()) {
-            response.send("{\"retcode\":500,\"message\":\"Unable to fetch requsted content\"}");
+            ctx.result("{\"retcode\":500,\"message\":\"Unable to fetch requsted content\"}");
             return;
         }
 
@@ -74,19 +69,19 @@ public final class AnnouncementsHandler implements Router {
         data = data
             .replace("{{DISPATCH_PUBLIC}}", dispatchDomain)
             .replace("{{SYSTEM_TIME}}", String.valueOf(System.currentTimeMillis()));
-        response.send("{\"retcode\":0,\"message\":\"OK\",\"data\": " + data + "}");
+        ctx.result("{\"retcode\":0,\"message\":\"OK\",\"data\": " + data + "}");
     }
 
-    private static void getPageResources(Request request, Response response) {
-        try (InputStream filestream = DataLoader.load(request.path())) {
-            String possibleFilename = Utils.toFilePath(DATA(request.path()));
+    private static void getPageResources(Context ctx) {
+        try (InputStream filestream = DataLoader.load(ctx.path())) {
+            String possibleFilename = Utils.toFilePath(DATA(ctx.path()));
 
-            MediaType fromExtension = MediaType.getByExtension(possibleFilename.substring(possibleFilename.lastIndexOf(".") + 1));
-            response.type((fromExtension != null) ? fromExtension.getMIME() : "application/octet-stream");
-            response.send(filestream.readAllBytes());
+            HttpUtils.MediaType fromExtension = HttpUtils.MediaType.getByExtension(possibleFilename.substring(possibleFilename.lastIndexOf(".") + 1));
+            ctx.contentType((fromExtension != null) ? fromExtension.getMIME() : "application/octet-stream");
+            ctx.result(filestream.readAllBytes());
         } catch (Exception e) {
-            Grasscutter.getLogger().warn("File does not exist: " + request.path());
-            response.status(404);
+            Grasscutter.getLogger().warn("File does not exist: " + ctx.path());
+            ctx.status(404);
         }
     }
 }

src/main/java/emu/grasscutter/server/http/handlers/GachaHandler.java

@@ -7,13 +7,11 @@ import emu.grasscutter.game.gacha.GachaBanner;
 import emu.grasscutter.game.gacha.GachaSystem;
 import emu.grasscutter.game.player.Player;
 import emu.grasscutter.server.http.Router;
-import emu.grasscutter.tools.Tools;
 import emu.grasscutter.utils.FileUtils;
+import emu.grasscutter.utils.HttpUtils;
 import emu.grasscutter.utils.Utils;
-import express.Express;
-import express.http.Request;
-import express.http.Response;
 import io.javalin.Javalin;
+import io.javalin.http.Context;
 import io.javalin.http.staticfiles.Location;
 
 import java.io.File;
@@ -31,38 +29,38 @@ import static emu.grasscutter.utils.Language.translate;
 public final class GachaHandler implements Router {
     public static final String gachaMappings = DATA(Utils.toFilePath("gacha/mappings.js"));
 
-    @Override public void applyRoutes(Express express, Javalin handle) {
-        express.get("/gacha", GachaHandler::gachaRecords);
-        express.get("/gacha/details", GachaHandler::gachaDetails);
+    @Override public void applyRoutes(Javalin javalin) {
+        javalin.get("/gacha", GachaHandler::gachaRecords);
+        javalin.get("/gacha/details", GachaHandler::gachaDetails);
 
-        express.useStaticFallback("/gacha/mappings", gachaMappings, Location.EXTERNAL);
+        javalin._conf.addSinglePageRoot("/gacha/mappings", gachaMappings, Location.EXTERNAL);
     }
 
-    private static void gachaRecords(Request request, Response response) {
+    private static void gachaRecords(Context ctx) {
         File recordsTemplate = new File(Utils.toFilePath(DATA("gacha/records.html")));
         if (!recordsTemplate.exists()) {
             Grasscutter.getLogger().warn("File does not exist: " + recordsTemplate);
-            response.status(500);
+            ctx.status(500);
             return;
         }
 
-        String sessionKey = request.query("s");
+        String sessionKey = ctx.queryParam("s");
         Account account = DatabaseHelper.getAccountBySessionKey(sessionKey);
         if (account == null) {
-            response.status(403).send("Requested account was not found");
+            ctx.status(403).result("Requested account was not found");
             return;
         }
         Player player = Grasscutter.getGameServer().getPlayerByAccountId(account.getId());
         if (player == null) {
-            response.status(403).send("No player associated with requested account");
+            ctx.status(403).result("No player associated with requested account");
             return;
         }
 
         int page = 0, gachaType = 0;
-        if (request.query("p") != null)
-            page = Integer.parseInt(request.query("p"));
-        if (request.query("gachaType") != null)
-            gachaType = Integer.parseInt(request.query("gachaType"));
+        if (ctx.queryParam("p") != null)
+            page = Integer.parseInt(ctx.queryParam("p"));
+        if (ctx.queryParam("gachaType") != null)
+            gachaType = Integer.parseInt(ctx.queryParam("gachaType"));
 
         String records = DatabaseHelper.getGachaRecords(player.getUid(), page, gachaType).toString();
         long maxPage = DatabaseHelper.getGachaRecordsMaxPage(player.getUid(), page, gachaType);
@@ -74,26 +72,27 @@ public final class GachaHandler implements Router {
             .replace("{{DATE}}", translate(player, "gacha.records.date"))
             .replace("{{ITEM}}", translate(player, "gacha.records.item"))
             .replace("{{LANGUAGE}}", Utils.getLanguageCode(account.getLocale()));
-        response.send(template);
+        ctx.contentType(HttpUtils.MediaType._html.getMIME());
+        ctx.result(template);
     }
 
-    private static void gachaDetails(Request request, Response response) {
+    private static void gachaDetails(Context ctx) {
         File detailsTemplate = new File(Utils.toFilePath(DATA("gacha/details.html")));
         if (!detailsTemplate.exists()) {
             Grasscutter.getLogger().warn("File does not exist: " + detailsTemplate);
-            response.status(500);
+            ctx.status(500);
             return;
         }
 
-        String sessionKey = request.query("s");
+        String sessionKey = ctx.queryParam("s");
         Account account = DatabaseHelper.getAccountBySessionKey(sessionKey);
         if (account == null) {
-            response.status(403).send("Requested account was not found");
+            ctx.status(403).result("Requested account was not found");
             return;
         }
         Player player = Grasscutter.getGameServer().getPlayerByAccountId(account.getId());
         if (player == null) {
-            response.status(403).send("No player associated with requested account");
+            ctx.status(403).result("No player associated with requested account");
             return;
         }
 
@@ -107,7 +106,7 @@ public final class GachaHandler implements Router {
                 .replace("{{LANGUAGE}}", Utils.getLanguageCode(account.getLocale()));
 
         // Get the banner info for the banner we want.
-        int scheduleId = Integer.parseInt(request.query("scheduleId"));
+        int scheduleId = Integer.parseInt(ctx.queryParam("scheduleId"));
         GachaSystem manager = Grasscutter.getGameServer().getGachaSystem();
         GachaBanner banner = manager.getGachaBanners().get(scheduleId);
 
@@ -135,6 +134,7 @@ public final class GachaHandler implements Router {
         template = template.replace("{{THREE_STARS}}", "[" + String.join(",", threeStarItems) + "]");
 
         // Done.
-        response.send(template);
+        ctx.contentType(HttpUtils.MediaType._html.getMIME());
+        ctx.result(template);
     }
 }

src/main/java/emu/grasscutter/server/http/handlers/GenericHandler.java

@@ -7,53 +7,52 @@ import emu.grasscutter.Grasscutter;
 import emu.grasscutter.server.http.objects.HttpJsonResponse;
 import emu.grasscutter.server.http.Router;
 import emu.grasscutter.server.http.objects.WebStaticVersionResponse;
-import express.Express;
-import express.http.Request;
-import express.http.Response;
+import emu.grasscutter.utils.HttpUtils;
 import io.javalin.Javalin;
+import io.javalin.http.Context;
 
 /**
  * Handles all generic, hard-coded responses.
  */
 public final class GenericHandler implements Router {
-    @Override public void applyRoutes(Express express, Javalin handle) {
+    @Override public void applyRoutes(Javalin javalin) {
         // hk4e-sdk-os.hoyoverse.com
-        express.get("/hk4e_global/mdk/agreement/api/getAgreementInfos", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"marketing_agreements\":[]}}"));
+        javalin.get("/hk4e_global/mdk/agreement/api/getAgreementInfos", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"marketing_agreements\":[]}}"));
         // hk4e-sdk-os.hoyoverse.com
         // this could be either GET or POST based on the observation of different clients
-        express.all("/hk4e_global/combo/granter/api/compareProtocolVersion", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"modified\":true,\"protocol\":{\"id\":0,\"app_id\":4,\"language\":\"en\",\"user_proto\":\"\",\"priv_proto\":\"\",\"major\":7,\"minimum\":0,\"create_time\":\"0\",\"teenager_proto\":\"\",\"third_proto\":\"\"}}}"));
+        HttpUtils.allRoutes(javalin, "/hk4e_global/combo/granter/api/compareProtocolVersion", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"modified\":true,\"protocol\":{\"id\":0,\"app_id\":4,\"language\":\"en\",\"user_proto\":\"\",\"priv_proto\":\"\",\"major\":7,\"minimum\":0,\"create_time\":\"0\",\"teenager_proto\":\"\",\"third_proto\":\"\"}}}"));
 
         // api-account-os.hoyoverse.com
-        express.post("/account/risky/api/check", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"id\":\"none\",\"action\":\"ACTION_NONE\",\"geetest\":null}}"));
+        javalin.post("/account/risky/api/check", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"id\":\"none\",\"action\":\"ACTION_NONE\",\"geetest\":null}}"));
 
         // sdk-os-static.hoyoverse.com
-        express.get("/combo/box/api/config/sdk/combo", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"vals\":{\"disable_email_bind_skip\":\"false\",\"email_bind_remind_interval\":\"7\",\"email_bind_remind\":\"true\"}}}"));
+        javalin.get("/combo/box/api/config/sdk/combo", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"vals\":{\"disable_email_bind_skip\":\"false\",\"email_bind_remind_interval\":\"7\",\"email_bind_remind\":\"true\"}}}"));
         // hk4e-sdk-os-static.hoyoverse.com
-        express.get("/hk4e_global/combo/granter/api/getConfig", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"protocol\":true,\"qr_enabled\":false,\"log_level\":\"INFO\",\"announce_url\":\"https://webstatic-sea.hoyoverse.com/hk4e/announcement/index.html?sdk_presentation_style=fullscreen\\u0026sdk_screen_transparent=true\\u0026game_biz=hk4e_global\\u0026auth_appid=announcement\\u0026game=hk4e#/\",\"push_alias_type\":2,\"disable_ysdk_guard\":false,\"enable_announce_pic_popup\":true}}"));
+        javalin.get("/hk4e_global/combo/granter/api/getConfig", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"protocol\":true,\"qr_enabled\":false,\"log_level\":\"INFO\",\"announce_url\":\"https://webstatic-sea.hoyoverse.com/hk4e/announcement/index.html?sdk_presentation_style=fullscreen\\u0026sdk_screen_transparent=true\\u0026game_biz=hk4e_global\\u0026auth_appid=announcement\\u0026game=hk4e#/\",\"push_alias_type\":2,\"disable_ysdk_guard\":false,\"enable_announce_pic_popup\":true}}"));
         // hk4e-sdk-os-static.hoyoverse.com
-        express.get("/hk4e_global/mdk/shield/api/loadConfig", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"id\":6,\"game_key\":\"hk4e_global\",\"client\":\"PC\",\"identity\":\"I_IDENTITY\",\"guest\":false,\"ignore_versions\":\"\",\"scene\":\"S_NORMAL\",\"name\":\"原神海外\",\"disable_regist\":false,\"enable_email_captcha\":false,\"thirdparty\":[\"fb\",\"tw\"],\"disable_mmt\":false,\"server_guest\":false,\"thirdparty_ignore\":{\"tw\":\"\",\"fb\":\"\"},\"enable_ps_bind_account\":false,\"thirdparty_login_configs\":{\"tw\":{\"token_type\":\"TK_GAME_TOKEN\",\"game_token_expires_in\":604800},\"fb\":{\"token_type\":\"TK_GAME_TOKEN\",\"game_token_expires_in\":604800}}}}"));
+        javalin.get("/hk4e_global/mdk/shield/api/loadConfig", new HttpJsonResponse("{\"retcode\":0,\"message\":\"OK\",\"data\":{\"id\":6,\"game_key\":\"hk4e_global\",\"client\":\"PC\",\"identity\":\"I_IDENTITY\",\"guest\":false,\"ignore_versions\":\"\",\"scene\":\"S_NORMAL\",\"name\":\"原神海外\",\"disable_regist\":false,\"enable_email_captcha\":false,\"thirdparty\":[\"fb\",\"tw\"],\"disable_mmt\":false,\"server_guest\":false,\"thirdparty_ignore\":{\"tw\":\"\",\"fb\":\"\"},\"enable_ps_bind_account\":false,\"thirdparty_login_configs\":{\"tw\":{\"token_type\":\"TK_GAME_TOKEN\",\"game_token_expires_in\":604800},\"fb\":{\"token_type\":\"TK_GAME_TOKEN\",\"game_token_expires_in\":604800}}}}"));
         // Test api?
         // abtest-api-data-sg.hoyoverse.com
-        express.post("/data_abtest_api/config/experiment/list", new HttpJsonResponse("{\"retcode\":0,\"success\":true,\"message\":\"\",\"data\":[{\"code\":1000,\"type\":2,\"config_id\":\"14\",\"period_id\":\"6036_99\",\"version\":\"1\",\"configs\":{\"cardType\":\"old\"}}]}"));
+        javalin.post("/data_abtest_api/config/experiment/list", new HttpJsonResponse("{\"retcode\":0,\"success\":true,\"message\":\"\",\"data\":[{\"code\":1000,\"type\":2,\"config_id\":\"14\",\"period_id\":\"6036_99\",\"version\":\"1\",\"configs\":{\"cardType\":\"old\"}}]}"));
 
         // log-upload-os.mihoyo.com
-        express.all("/log/sdk/upload", new HttpJsonResponse("{\"code\":0}"));
-        express.all("/sdk/upload", new HttpJsonResponse("{\"code\":0}"));
-        express.post("/sdk/dataUpload", new HttpJsonResponse("{\"code\":0}"));
+        HttpUtils.allRoutes(javalin, "/log/sdk/upload", new HttpJsonResponse("{\"code\":0}"));
+        HttpUtils.allRoutes(javalin, "/sdk/upload", new HttpJsonResponse("{\"code\":0}"));
+        javalin.post("/sdk/dataUpload", new HttpJsonResponse("{\"code\":0}"));
         // /perf/config/verify?device_id=xxx&platform=x&name=xxx
-        express.all("/perf/config/verify", new HttpJsonResponse("{\"code\":0}"));
+        HttpUtils.allRoutes(javalin, "/perf/config/verify", new HttpJsonResponse("{\"code\":0}"));
 
         // webstatic-sea.hoyoverse.com
-        express.get("/admin/mi18n/plat_oversea/*", new WebStaticVersionResponse());
+        javalin.get("/admin/mi18n/plat_oversea/*", new WebStaticVersionResponse());
 
-        express.get("/status/server", GenericHandler::serverStatus);
+        javalin.get("/status/server", GenericHandler::serverStatus);
     }
 
-    private static void serverStatus(Request request, Response response) {
+    private static void serverStatus(Context ctx) {
         int playerCount = Grasscutter.getGameServer().getPlayers().size();
         int maxPlayer = ACCOUNT.maxPlayer;
         String version = GameConstants.VERSION;
 
-        response.send("{\"retcode\":0,\"status\":{\"playerCount\":" + playerCount + ",\"maxPlayer\":" + maxPlayer + ",\"version\":\"" + version + "\"}}");
+        ctx.result("{\"retcode\":0,\"status\":{\"playerCount\":" + playerCount + ",\"maxPlayer\":" + maxPlayer + ",\"version\":\"" + version + "\"}}");
     }
 }

src/main/java/emu/grasscutter/server/http/handlers/LogHandler.java

 package emu.grasscutter.server.http.handlers;
 
 import emu.grasscutter.server.http.Router;
-import express.Express;
-import express.http.Request;
-import express.http.Response;
 import io.javalin.Javalin;
+import io.javalin.http.Context;
 
 /**
  * Handles logging requests made to the server.
  */
 public final class LogHandler implements Router {
-    @Override public void applyRoutes(Express express, Javalin handle) {
+    @Override public void applyRoutes(Javalin javalin) {
         // overseauspider.yuanshen.com
-        express.post("/log", LogHandler::log);
+        javalin.post("/log", LogHandler::log);
         // log-upload-os.mihoyo.com
-        express.post("/crash/dataUpload", LogHandler::log);
+        javalin.post("/crash/dataUpload", LogHandler::log);
     }
 
-    private static void log(Request request, Response response) {
+    private static void log(Context ctx) {
         // TODO: Figure out how to dump request body and log to file.
-        response.send("{\"code\":0}");
+        ctx.result("{\"code\":0}");
     }
 }

src/main/java/emu/grasscutter/server/http/objects/HttpJsonResponse.java

@@ -6,14 +6,14 @@ import java.util.Objects;
 
 import emu.grasscutter.Grasscutter;
 import emu.grasscutter.Grasscutter.ServerDebugMode;
-import express.http.HttpContextHandler;
-import express.http.Request;
-import express.http.Response;
+import io.javalin.http.Context;
+import io.javalin.http.Handler;
+import org.jetbrains.annotations.NotNull;
 
 import static emu.grasscutter.config.Configuration.*;
 import static emu.grasscutter.utils.Language.translate;
 
-public final class HttpJsonResponse implements HttpContextHandler {
+public final class HttpJsonResponse implements Handler {
     private final String response;
     private final String[] missingRoutes = { // TODO: When http requests for theses routes are found please remove it from this list and update the route request type in the DispatchServer
             "/common/hk4e_global/announcement/api/getAlertPic",
@@ -33,11 +33,11 @@ public final class HttpJsonResponse implements HttpContextHandler {
     }
 
     @Override
-    public void handle(Request req, Response res) throws IOException {
+    public void handle(@NotNull Context ctx) throws Exception {
         // Checking for ALL here isn't required as when ALL is enabled enableDevLogging() gets enabled
-        if (DISPATCH_INFO.logRequests == ServerDebugMode.MISSING && Arrays.stream(missingRoutes).anyMatch(x -> Objects.equals(x, req.baseUrl()))) {
-            Grasscutter.getLogger().info(translate("messages.dispatch.request", req.ip(), req.method(), req.baseUrl()) + (DISPATCH_INFO.logRequests == ServerDebugMode.MISSING ? "(MISSING)" : ""));
+        if (DISPATCH_INFO.logRequests == ServerDebugMode.MISSING && Arrays.stream(missingRoutes).anyMatch(x -> Objects.equals(x, ctx.endpointHandlerPath()))) {
+            Grasscutter.getLogger().info(translate("messages.dispatch.request", ctx.ip(), ctx.method(), ctx.endpointHandlerPath()) + (DISPATCH_INFO.logRequests == ServerDebugMode.MISSING ? "(MISSING)" : ""));
         }
-        res.send(response);
+        ctx.result(response);
     }
 }

src/main/java/emu/grasscutter/server/http/objects/WebStaticVersionResponse.java

 package emu.grasscutter.server.http.objects;
 
 import emu.grasscutter.Grasscutter;
-import emu.grasscutter.data.DataLoader;
 import emu.grasscutter.utils.FileUtils;
-import emu.grasscutter.utils.Utils;
-import express.http.HttpContextHandler;
-import express.http.MediaType;
-import express.http.Request;
-import express.http.Response;
-import io.javalin.core.util.FileUtil;
-
-import static emu.grasscutter.config.Configuration.DATA;
+import emu.grasscutter.utils.HttpUtils;
+import io.javalin.http.Context;
+import io.javalin.http.Handler;
+
 import static emu.grasscutter.config.Configuration.DISPATCH_INFO;
 
 import java.io.IOException;
 import java.io.InputStream;
 
-public class WebStaticVersionResponse implements HttpContextHandler {
+public class WebStaticVersionResponse implements Handler {
 
     @Override
-    public void handle(Request request, Response response) throws IOException {
-        String requestFor = request.path().substring(request.path().lastIndexOf("-") + 1);
+    public void handle(Context ctx) throws IOException {
+        String requestFor = ctx.path().substring(ctx.path().lastIndexOf("-") + 1);
 
-        getPageResources("/webstatic/" + requestFor, response);
+        getPageResources("/webstatic/" + requestFor, ctx);
         return;
     }
 
-    private static void getPageResources(String path, Response response) {
+    private static void getPageResources(String path, Context ctx) {
         try (InputStream filestream = FileUtils.readResourceAsStream(path)) {
 
-            MediaType fromExtension = MediaType.getByExtension(path.substring(path.lastIndexOf(".") + 1));
-            response.type((fromExtension != null) ? fromExtension.getMIME() : "application/octet-stream");
-            response.send(filestream.readAllBytes());
+            HttpUtils.MediaType fromExtension = HttpUtils.MediaType.getByExtension(path.substring(path.lastIndexOf(".") + 1));
+            ctx.contentType((fromExtension != null) ? fromExtension.getMIME() : "application/octet-stream");
+            ctx.result(filestream.readAllBytes());
         } catch (Exception e) {
             if (DISPATCH_INFO.logRequests == Grasscutter.ServerDebugMode.MISSING) {
                 Grasscutter.getLogger().warn("Webstatic File Missing: " + path);
             }
-            response.status(404);
+            ctx.status(404);
         }
     }
 }