Migrate HTTP server to Javalin and remove legacy handlers

Replaced the existing HttpServer implementation and associated handler classes (`AbstractHandler`, `ActionHandler`, `GuildHandler`, `RootHandler`) with a Javalin-based routing system. Improved modularity by introducing `ActionRoutes` and `GuildRoutes` for route definitions, and centralized JSON mapping using `GsonJsonMapper`. Simplified caching via the new `ResponseCache` utility, updated `WebModule` for cleaner timeout handling, and extended test coverage for API endpoints.

.junie/plans/javalin-webapi-refactor.md

@@ -0,0 +1,188 @@
+---
+sessionId: session-260923-111902-5uwc
+---
+
+# Requirements
+
+### Overview & Goals
+Replace the hand-rolled `com.sun.net.httpserver` stack in `me.bobert.netneutrality.http.server` with Javalin, so the bot's embedded API needs far fewer custom classes and gains correct status codes, JSON handling and error responses. Additionally simplify the outbound `WebModule` HTTP client.
+
+### Scope
+**In scope**
+- `WebApi` becomes a thin Javalin-based `Lifecycle` component (same priority 70, same `NETNEUTRALITY_API_PORT` setting).
+- Delete `AbstractHandler`, `RootHandler`, `ActionHandler`, `GuildHandler`; their logic moves into small route-registration units.
+- Standardise the API layer on **Gson** — remove `org.json` (`JSONObject`/`JSONArray`) usage from the HTTP server package.
+- Correct HTTP semantics: 404 for unknown guilds/paths, 405 for wrong methods, 500 on exceptions, UTF-8 safe bodies.
+- Simplify `WebModule` (outbound OkHttp wrapper): extract the static cache, remove duplicated/unused members.
+
+**Out of scope**
+- Changing the public URL shape of existing endpoints (`/`, `/actions/*`, `/guilds/*`) — paths and payload keys stay backwards compatible.
+- Authentication/authorisation for the API.
+- Migrating `org.json` usage elsewhere in the project (e.g. task classes using `WebModule.getAsObject()`).
+
+### Functional Requirements
+- `GET /` → HTML liveness page (unchanged text).
+- `GET /actions/status` → `{"health":...,"ping":...}`.
+- `POST /actions/shutdown` → runs the shutdown hook and exits (accept `GET` too for compatibility if desired).
+- `GET /actions/settings/current/{guildId}` → `{"status":"ok","settings":{...}}`, or 404 + `{"status":"error"}` for an unknown guild.
+- `POST /actions/settings/reload/{guildId}` → reloads the guild setting cache, `{"status":"true"}`; 404 for an unknown guild.
+- `GET /guilds/owner` → array of `{guild_id, owner_id}`.
+- `GET /guilds/channels/{guildId}` and `GET /guilds/roles/{guildId}` → arrays of id/name objects; 404 for an unknown guild.
+- Requests arriving before JDA is ready must return 503 rather than throwing an NPE.
+
+### Non-Functional Requirements
+- Startup/shutdown stays deterministic through `ApplicationContext` — `stop()` must release the port.
+- Shaded jar must still run (`maven-shade-plugin`); Javalin/Jetty service files need merging.
+- No behavioural regression for existing consumers of the endpoints.
+
+# Technical Design
+
+### Current Implementation
+- `WebApi.java` (92 lines) implements `Lifecycle` (priority 70), creates an `HttpServer`, registers three contexts and a fixed pool built from `BaseThreadFactory("web-api")`. Constructed in `App.java:154`.
+- `AbstractHandler` offers `sendStringResponse`/`sendJsonResponse`; both hardcode status 200 and use `str.length()` instead of byte length (breaks non-ASCII).
+- `ActionHandler` / `GuildHandler` route via `if (path.startsWith(...))` chains and parse ids with `getRequestURI().toString().split("/")`; they mix Gson and `org.json`, never check the HTTP method, and call `jda.getGuildById()` twice in places.
+- `WebModule` is an unrelated *outbound* OkHttp wrapper with a builder, a static LRU cache and a `CachedResponse` record; it builds a brand-new `OkHttpClient` per request and has three redundant timeout setters plus unused `elapsedTime`/`errorMessage` accessors.
+
+### Key Decisions
+1. **Javalin** (6.x, JDK 17+ / Java 25 compatible) as the embedded server — removes routing, method matching, error mapping and content-type handling code.
+2. **Gson only** in the HTTP layer: register a `GsonJsonMapper` on the Javalin config so `ctx.json(obj)` works with plain records/maps; `org.json` disappears from `http/server`.
+3. **Route groups instead of handler classes**: `ActionRoutes` and `GuildRoutes` expose a single `static void register(Javalin app, deps...)`, so `AbstractHandler`, `RootHandler`, `ActionHandler`, `GuildHandler` are all deleted (4 classes → 2 tiny registrars).
+4. **Guild lookup guard**: one private helper resolves `{guildId}` → `Guild` or throws `NotFoundResponse`, replacing repeated null checks.
+5. **WebModule**: keep the builder API used by callers, but move the cache into a package-private `ResponseCache`, share a single static `OkHttpClient` and derive per-request timeouts with `newBuilder()`.
+
+### Proposed Changes
+**`http/server/WebApi.java`**
+```java
+public class WebApi implements Lifecycle {
+    private Javalin app;
+    @Override public int priority() { return 70; }
+    @Override public void start() {
+        int port = Integer.parseInt(settings.get("NETNEUTRALITY_API_PORT", "9000"));
+        app = Javalin.create(cfg -> cfg.jsonMapper(new GsonJsonMapper()));
+        app.get("/", ctx -> ctx.html(LIVENESS_HTML));
+        ActionRoutes.register(app, jdaSupplier, guildServices, shutdownHook);
+        GuildRoutes.register(app, jdaSupplier);
+        app.exception(Exception.class, (e, ctx) -> { log.error(...); ctx.status(500).json(Map.of("status","error")); });
+        app.start(port);
+    }
+    @Override public void stop() { if (app != null) { app.stop(); app = null; } }
+}
+```
+
+**`http/server/GuildRoutes.java`** — `/guilds/owner`, `/guilds/channels/{guildId}`, `/guilds/roles/{guildId}` mapped to `List<Map<String,String>>` and returned via `ctx.json(...)`.
+
+**`http/server/ActionRoutes.java`** — `/actions/status`, `/actions/shutdown`, `/actions/settings/current/{guildId}`, `/actions/settings/reload/{guildId}`.
+
+**`http/server/GsonJsonMapper.java`** — ~15 lines implementing Javalin's `JsonMapper` over a shared `Gson`.
+
+**`http/WebModule.java`** — shared client, cache extracted, redundant setters/accessors dropped; public builder methods used by callers remain.
+
+### Data Models / Contracts
+Small records replace ad-hoc JSON building, serialized by Gson with the existing key names:
+```java
+record GuildOwner(String guild_id, String owner_id) {}
+record NamedEntity(String channel_id, String channel_name) {}
+record StatusResponse(String health, String ping) {}
+```
+
+### File Structure
+```
+src/main/java/me/bobert/netneutrality/http/
+  WebModule.java              (modified)
+  server/WebApi.java          (rewritten, Javalin)
+  server/GsonJsonMapper.java  (new)
+  server/ActionRoutes.java    (new)
+  server/GuildRoutes.java     (new)
+  server/AbstractHandler.java (deleted)
+  server/RootHandler.java     (deleted)
+  server/ActionHandler.java   (deleted)
+  server/GuildHandler.java    (deleted)
+pom.xml                       (+ io.javalin:javalin, shade transformer)
+```
+
+### Architecture Diagram
+```mermaid
+graph LR
+App-->ApplicationContext
+ApplicationContext-->WebApi
+WebApi-->Javalin
+WebApi-->GsonJsonMapper
+Javalin-->ActionRoutes
+Javalin-->GuildRoutes
+ActionRoutes-->GuildServiceProvider
+GuildRoutes-->JDA
+```
+
+### Risks
+- **Shaded jar**: Jetty/Javalin rely on `META-INF/services`; the shade plugin needs `ServicesResourceTransformer`, otherwise startup fails only in the packaged build.
+- **Jar size / SLF4J binding**: Jetty logs through SLF4J; project already has log4j + slf4j — check for duplicate bindings.
+- **JDA not ready**: `jdaSupplier.get()` may be null; guard with a 503 mapping.
+- `System.exit(0)` in the shutdown route must run after the response is flushed.
+
+# Testing
+
+### Validation Approach
+Build with `./mvnw -q verify` (checkstyle included), then start the app/`WebApi` on an ephemeral port and exercise every endpoint with `curl`, comparing payload shape against the pre-refactor behaviour.
+
+### Key Scenarios
+- `GET /` returns 200 and the HTML liveness text.
+- `GET /actions/status` returns 200 `application/json` with `health` and `ping`.
+- `GET /guilds/owner` returns a JSON array with `guild_id`/`owner_id` keys.
+- `GET /guilds/channels/{id}` and `/guilds/roles/{id}` return arrays with `channel_id`/`channel_name`.
+- `GET /actions/settings/current/{id}` returns `{"status":"ok","settings":{...}}`.
+
+### Edge Cases
+- Unknown guild id → 404 with `{"status":"error"}` (previously 200).
+- Unknown path → 404 (previously echoed the path with 200).
+- Wrong method on a route → 405.
+- Non-ASCII content in settings values round-trips correctly (old `str.length()` bug).
+- `Lifecycle.stop()` frees the port — a second `start()` on the same port succeeds.
+
+### Test Changes
+- Add a lightweight JUnit test starting `WebApi` on port 0 with a mocked `Supplier<JDA>` and `GuildServiceProvider`, hitting the routes with Javalin's test client or `java.net.http.HttpClient`.
+- Add a `WebModule` test covering cache hit/expiry after the cache extraction.
+
+# Delivery Steps
+
+### ✓ Step 1: Add Javalin dependency and Gson JSON mapper
+The project builds with Javalin available and a Gson-backed JSON mapper ready for use.
+
+- Add `io.javalin:javalin` (6.x) to `pom.xml` dependencies.
+- Add `ServicesResourceTransformer` to the `maven-shade-plugin` configuration so Jetty/Javalin service files survive shading.
+- Create `http/server/GsonJsonMapper.java` implementing Javalin's `JsonMapper` over a shared `Gson` instance.
+- Verify `./mvnw -q package` succeeds and the shaded jar still starts.
+
+### ✓ Step 2: Rewrite WebApi as a Javalin Lifecycle component
+`WebApi` starts and stops a Javalin server while keeping its Lifecycle contract and the root endpoint.
+
+- Replace the `HttpServer`/`ExecutorService` fields with a `Javalin app` field.
+- Build the instance in `start()` with the `GsonJsonMapper`, reading `NETNEUTRALITY_API_PORT` from `SettingsProvider` as today.
+- Register `GET /` returning the liveness HTML and delete `RootHandler.java`.
+- Add global `exception` and `error` handlers returning 500/404 JSON, plus a 503 guard when `jdaSupplier.get()` is null.
+- Implement `stop()` via `app.stop()`; keep `priority() == 70` and the `App.java` construction site unchanged.
+
+### ✓ Step 3: Migrate guild endpoints to GuildRoutes
+All `/guilds/*` endpoints are served by Javalin route lambdas with proper status codes and Gson serialization.
+
+- Create `http/server/GuildRoutes.register(Javalin, Supplier<JDA>)`.
+- Map `GET /guilds/owner`, `GET /guilds/channels/{guildId}`, `GET /guilds/roles/{guildId}` using path params instead of `split("/")`.
+- Return `List<record>` payloads via `ctx.json(...)`, preserving the existing `guild_id`/`owner_id`/`channel_id`/`channel_name` keys.
+- Resolve guilds through a shared helper that throws `NotFoundResponse` for unknown ids (single `getGuildById` call).
+- Delete `GuildHandler.java`.
+
+### ✓ Step 4: Migrate action endpoints to ActionRoutes
+All `/actions/*` endpoints run on Javalin, with `org.json` fully removed from the HTTP server package.
+
+- Create `http/server/ActionRoutes.register(Javalin, Supplier<JDA>, GuildServiceProvider, Runnable)`.
+- Map `/actions/status`, `/actions/shutdown`, `/actions/settings/current/{guildId}`, `/actions/settings/reload/{guildId}`.
+- Replace `JSONObject`/`JSONArray` with Gson-serialized maps/records keeping the same response keys.
+- Ensure the shutdown route flushes its response before running the hook and exiting.
+- Delete `ActionHandler.java` and `AbstractHandler.java`, and add endpoint tests starting `WebApi` on port 0 with mocked JDA/guild services.
+
+### ✓ Step 5: Simplify the outbound WebModule client
+`WebModule` keeps its builder API but sheds duplicated state and its inlined cache.
+
+- Extract the static LRU cache and `CachedResponse` into a package-private `ResponseCache` class in `http/`.
+- Share a single static `OkHttpClient` and derive per-request timeouts with `newBuilder()` instead of constructing a client per build.
+- Collapse the redundant `timeout`/`connectTimeout`/`readTimeout`/`writeTimeout` setters and remove unused accessors (`getErrorMessage`, `elapsedTime` exposure) after checking call sites.
+- Add a unit test covering cache hit, expiry and POST bypass; verify existing `WebModule` callers still compile.

pom.xml

@@ -183,6 +183,12 @@
             <version>5.3.2</version>
         </dependency>
 
+        <dependency>
+            <groupId>io.javalin</groupId>
+            <artifactId>javalin</artifactId>
+            <version>6.7.0</version>
+        </dependency>
+
         <dependency>
             <groupId>org.hibernate.orm</groupId>
             <artifactId>hibernate-core</artifactId>
@@ -219,6 +225,13 @@
             <groupId>org.gitlab4j</groupId>
             <artifactId>gitlab4j-api</artifactId>
             <version>6.2.0</version>
+            <exclusions>
+                <!-- Clashes with the Servlet 5 API used by Javalin's Jetty 11 in the shaded jar. -->
+                <exclusion>
+                    <groupId>jakarta.servlet</groupId>
+                    <artifactId>jakarta.servlet-api</artifactId>
+                </exclusion>
+            </exclusions>
         </dependency>
 
         <dependency>

src/main/java/me/bobert/netneutrality/http/ResponseCache.java

@@ -0,0 +1,65 @@
+package me.bobert.netneutrality.http;
+
+/*
+ * Copyright (c) anthorob
+ *
+ * https://discord.gg/qUa6zNFZsd
+ */
+
+import java.util.Collections;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Optional;
+
+/**
+ * Small LRU cache holding responses of outbound {@link WebModule} GET requests.
+ */
+final class ResponseCache {
+
+    private static final int MAX_ENTRIES = 50;
+
+    private static final Map<String, CachedResponse> entries = Collections.synchronizedMap(
+        new LinkedHashMap<>(100, 0.75f, true) {
+            @Override
+            protected boolean removeEldestEntry(Map.Entry<String, CachedResponse> eldest) {
+                return size() > MAX_ENTRIES;
+            }
+        }
+    );
+
+    private ResponseCache() {
+    }
+
+    /**
+     * Returns the cached response for the key when it is still valid.
+     *
+     * @param key the cache key
+     * @return the cached response, or empty when absent or expired
+     */
+    static Optional<CachedResponse> get(String key) {
+        CachedResponse cached = entries.get(key);
+        return cached != null && !cached.isExpired() ? Optional.of(cached) : Optional.empty();
+    }
+
+    static void put(String key, CachedResponse response) {
+        entries.put(key, response);
+    }
+
+    static void invalidate(String url) {
+        entries.keySet().removeIf(key -> key.contains(url));
+    }
+
+    /**
+     * A response body kept alongside its status code until {@code expirationTime}.
+     */
+    record CachedResponse(int statusCode, String body, long expirationTime) {
+
+        boolean isExpired() {
+            return System.currentTimeMillis() > expirationTime;
+        }
+
+        Optional<String> getBody() {
+            return Optional.ofNullable(body);
+        }
+    }
+}

src/main/java/me/bobert/netneutrality/http/WebModule.java

@@ -9,7 +9,7 @@ package me.bobert.netneutrality.http;
 import com.google.gson.Gson;
 import io.sentry.Breadcrumb;
 import io.sentry.Sentry;
-import okhttp3.Headers;
+import me.bobert.netneutrality.http.ResponseCache.CachedResponse;
 import okhttp3.MediaType;
 import okhttp3.OkHttpClient;
 import okhttp3.Request;
@@ -21,11 +21,8 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
-import java.util.Collections;
 import java.util.HashMap;
-import java.util.LinkedHashMap;
 import java.util.Map;
-import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 
 public class WebModule {
@@ -34,20 +31,13 @@ public class WebModule {
     }
 
     private static final String USER_AGENT = "Net Neutrality/%s (Discord bot, discord.gg/trAqhQ5Wsr)";
+    private static final OkHttpClient CLIENT = new OkHttpClient();
     private static volatile String defaultVersion = "0.0.0";
     private static final Logger log = LoggerFactory.getLogger(WebModule.class);
 
     public static void setDefaultVersion(String version) {
         defaultVersion = version;
     }
-    private static final Map<String, CachedResponse> cache = Collections.synchronizedMap(
-        new LinkedHashMap<>(100, 0.75f, true) {
-            @Override
-            protected boolean removeEldestEntry(Map.Entry<String, CachedResponse> eldest) {
-                return size() > 50; // Limit cache to 50 entries
-            }
-        }
-    );
 
     private final Method method;
     private final String url;
@@ -62,7 +52,7 @@ public class WebModule {
         this.url = builder.url;
         this.client = builder.client;
         this.headers = builder.headers;
-        this.cacheExpirationMillis = builder.timeUnit.toMillis(builder.timeout);
+        this.cacheExpirationMillis = builder.timeUnit.toMillis(builder.cacheTimeout);
         this.request = builder.request;
     }
 
@@ -74,7 +64,7 @@ public class WebModule {
      * @param url the URL of the cached response to invalidate
      */
     public static void invalidateCache(String url) {
-        cache.keySet().removeIf(s -> s.contains(url));
+        ResponseCache.invalidate(url);
     }
 
     /**
@@ -86,60 +76,49 @@ public class WebModule {
      * POST requests do not support caching.
      *
      * @return the {@code WebModule} instance, allowing further interaction with the response
-     * @throws RuntimeException if the request fails
      */
     public WebModule request() {
         String cacheKey = createCacheKey(method, url, headers);
 
-        if (method == Method.GET && cacheKey != null) {
-            CachedResponse cachedResponse = cache.get(cacheKey);
+        if (cacheKey != null) {
+            CachedResponse cached = ResponseCache.get(cacheKey).orElse(null);
 
-            if (cachedResponse != null && !cachedResponse.isExpired()) {
+            if (cached != null) {
                 log.debug("Retrieving cached response: {}", cacheKey);
-                this.cachedResponse = cachedResponse;
+                this.cachedResponse = cached;
                 return this;
             }
         }
 
-        long startTime = System.currentTimeMillis();
         try (Response response = client.newCall(request).execute()) {
-            long elapsedTime = System.currentTimeMillis() - startTime;
             Sentry.addBreadcrumb(Breadcrumb.http(url, method.name(), response.code()));
-            String body = response.body().string();
 
             this.cachedResponse = new CachedResponse(
                 response.code(),
-                response.headers(),
-                elapsedTime,
-                body,
-                System.currentTimeMillis() + cacheExpirationMillis,
-                null
+                response.body().string(),
+                System.currentTimeMillis() + cacheExpirationMillis
             );
         } catch (IOException e) {
-            long elapsedTime = System.currentTimeMillis() - startTime;
             log.error("Request failed: {}", e.getMessage(), e);
             Sentry.captureException(e);
 
             this.cachedResponse = new CachedResponse(
                 0, // Status code 0 indicates a failure
-                new Headers.Builder().build(),
-                elapsedTime,
                 null,
-                System.currentTimeMillis() + cacheExpirationMillis,
-                e.getMessage()
+                System.currentTimeMillis() + cacheExpirationMillis
             );
         }
 
-        if (method == Method.GET && cacheKey != null) {
-            cache.put(cacheKey, this.cachedResponse);
+        if (cacheKey != null) {
+            ResponseCache.put(cacheKey, this.cachedResponse);
         }
 
         return this;
     }
 
     private String createCacheKey(Method method, String url, Map<String, String> headers) {
-        if (method == Method.POST) {
-            return null; // no cache for post requests
+        if (method != Method.GET) {
+            return null; // only GET requests are cached
         }
 
         StringBuilder keyBuilder = new StringBuilder(method.name()).append(":").append(url);
@@ -176,12 +155,9 @@ public class WebModule {
         private final String url;
         private final String version;
         private Method method = Method.GET;
-        private long timeout = 5;
+        private long cacheTimeout = 5;
         private TimeUnit timeUnit = TimeUnit.MINUTES;
-        private OkHttpClient client;
-        private long connectTimeout;
-        private long readTimeout;
-        private long writeTimeout;
+        private OkHttpClient client = CLIENT;
         private final Map<String, String> headers = new HashMap<>();
         private final Map<String, String> params = new HashMap<>();
 
@@ -242,51 +218,24 @@ public class WebModule {
          * @return the current {@code Builder} instance for chaining
          */
         public Builder cache(long timeout, TimeUnit timeUnit) {
-            this.timeout = timeout;
+            this.cacheTimeout = timeout;
             this.timeUnit = timeUnit;
             return this;
         }
 
+        /**
+         * Sets the connect, read and write timeouts of the HTTP client.
+         *
+         * @param timeout  the timeout duration
+         * @param timeUnit the unit of time for the timeout
+         * @return the current {@code Builder} instance for chaining
+         */
         public Builder timeout(long timeout, TimeUnit timeUnit) {
-            this.connectTimeout = timeUnit.toMillis(timeout);
-            this.readTimeout = timeUnit.toMillis(timeout);
-            this.writeTimeout = timeUnit.toMillis(timeout);
-            return this;
-        }
-
-        /**
-         * Sets the connection timeout for the HTTP client.
-         *
-         * @param timeout  the timeout duration
-         * @param timeUnit the unit of time for the timeout
-         * @return the current {@code Builder} instance for chaining
-         */
-        public Builder connectTimeout(long timeout, TimeUnit timeUnit) {
-            this.connectTimeout = timeUnit.toMillis(timeout);
-            return this;
-        }
-
-        /**
-         * Sets the read timeout for the HTTP client.
-         *
-         * @param timeout  the timeout duration
-         * @param timeUnit the unit of time for the timeout
-         * @return the current {@code Builder} instance for chaining
-         */
-        public Builder readTimeout(long timeout, TimeUnit timeUnit) {
-            this.readTimeout = timeUnit.toMillis(timeout);
-            return this;
-        }
-
-        /**
-         * Sets the write timeout for the HTTP client.
-         *
-         * @param timeout  the timeout duration
-         * @param timeUnit the unit of time for the timeout
-         * @return the current {@code Builder} instance for chaining
-         */
-        public Builder writeTimeout(long timeout, TimeUnit timeUnit) {
-            this.writeTimeout = timeUnit.toMillis(timeout);
+            this.client = CLIENT.newBuilder()
+                .connectTimeout(timeout, timeUnit)
+                .readTimeout(timeout, timeUnit)
+                .writeTimeout(timeout, timeUnit)
+                .build();
             return this;
         }
 
@@ -317,30 +266,9 @@ public class WebModule {
          * @return a new {@code WebModule} instance
          */
         public WebModule build() {
-            this.client = new OkHttpClient.Builder()
-                .connectTimeout(connectTimeout, TimeUnit.MILLISECONDS)
-                .writeTimeout(writeTimeout, TimeUnit.MILLISECONDS)
-                .readTimeout(readTimeout, TimeUnit.MILLISECONDS)
-                .build();
             this.request = createRequest();
 
             return new WebModule(this);
         }
     }
-
-    private record CachedResponse(int statusCode, Headers headers, long elapsedTime, String body, long expirationTime,
-                                  String errorMessage) {
-
-        public boolean isExpired() {
-                return System.currentTimeMillis() > expirationTime;
-            }
-
-            public Optional<String> getBody() {
-                return Optional.ofNullable(body);
-            }
-
-            public Optional<String> getErrorMessage() {
-                return Optional.ofNullable(errorMessage);
-            }
-        }
 }

src/main/java/me/bobert/netneutrality/http/server/AbstractHandler.java

@@ -1,33 +0,0 @@
-package me.bobert.netneutrality.http.server;
-
-/*
- * Copyright (c) anthorob
- *
- * https://discord.gg/qUa6zNFZsd
- */
-
-import com.sun.net.httpserver.HttpExchange;
-import com.sun.net.httpserver.HttpHandler;
-
-import java.io.IOException;
-import java.io.OutputStream;
-
-public abstract class AbstractHandler implements HttpHandler {
-
-    public abstract void handle(HttpExchange exchange) throws IOException;
-
-    public void sendStringResponse(HttpExchange exchange, String str) throws IOException {
-        exchange.sendResponseHeaders(200, str.length());
-        OutputStream os = exchange.getResponseBody();
-        os.write(str.getBytes());
-        os.close();
-    }
-
-    public void sendJsonResponse(HttpExchange exchange, String str) throws IOException {
-        exchange.getResponseHeaders().add("Content-Type", "application/json");
-        exchange.sendResponseHeaders(200, str.length());
-        OutputStream os = exchange.getResponseBody();
-        os.write(str.getBytes());
-        os.close();
-    }
-}

src/main/java/me/bobert/netneutrality/http/server/ActionHandler.java

@@ -1,97 +0,0 @@
-package me.bobert.netneutrality.http.server;
-
-/*
- * Copyright (c) anthorob
- *
- * https://discord.gg/qUa6zNFZsd
- */
-
-import com.google.gson.Gson;
-import com.sun.net.httpserver.HttpExchange;
-import me.bobert.netneutrality.db.service.GuildServiceProvider;
-import me.bobert.netneutrality.db.service.GuildService;
-import net.dv8tion.jda.api.JDA;
-import net.dv8tion.jda.api.entities.Guild;
-import org.apache.logging.log4j.LogManager;
-import org.json.JSONObject;
-
-import java.io.IOException;
-import java.util.Map;
-import java.util.Objects;
-import java.util.TreeMap;
-import java.util.function.Supplier;
-
-public class ActionHandler extends AbstractHandler {
-    private final Supplier<JDA> jdaSupplier;
-    private final GuildServiceProvider guildServices;
-    private final Runnable shutdownHook;
-
-    public ActionHandler(Supplier<JDA> jdaSupplier, GuildServiceProvider guildServices, Runnable shutdownHook) {
-        this.jdaSupplier = Objects.requireNonNull(jdaSupplier, "jdaSupplier");
-        this.guildServices = Objects.requireNonNull(guildServices, "guildServices");
-        this.shutdownHook = Objects.requireNonNull(shutdownHook, "shutdownHook");
-    }
-
-    @Override
-    public void handle(HttpExchange exchange) throws IOException {
-
-        String path = exchange.getRequestURI().getRawPath();
-
-        if (path.equals("/actions/shutdown")) {
-            LogManager.getLogger(ActionHandler.class).info("Request to shutdown received");
-            shutdownHook.run();
-            sendStringResponse(exchange, "Shutting down..");
-
-            System.exit(0);
-            return;
-        }
-
-        if (path.equals("/actions/status")) {
-            TreeMap<String, String> json = new TreeMap<>();
-            JDA jda = jdaSupplier.get();
-            json.put("health", String.valueOf(jda.getStatus()));
-            json.put("ping", String.valueOf(jda.getGatewayPing()));
-
-            sendJsonResponse(exchange, new Gson().toJson(json));
-            return;
-        }
-
-        if (path.startsWith("/actions/settings/current/")) {
-            JSONObject json = new JSONObject();
-            String[] args = exchange.getRequestURI().toString().split("/");
-            String guildId = args[args.length - 1];
-
-            Guild guild = jdaSupplier.get().getGuildById(guildId);
-            if (guild != null) {
-                GuildService service = guildServices.get(guild);
-                Map<String, String> settings = service.getGuildSettingService().getSettings();
-                JSONObject setting = new JSONObject(settings);
-
-                json.put("status", "ok");
-                json.put("settings", setting);
-            } else {
-                json.put("status", "error");
-            }
-
-            sendJsonResponse(exchange, json.toString());
-            return;
-        }
-
-        if (path.startsWith("/actions/settings/reload/")) {
-            TreeMap<String, String> json = new TreeMap<>();
-            String[] args = exchange.getRequestURI().toString().split("/");
-            String guildId = args[args.length - 1];
-
-            boolean ok = true; //TODO: add bool
-            guildServices.get(guildId).getGuildSettingService().reloadSettingsCache();
-
-            json.put("status", String.valueOf(ok));
-            sendJsonResponse(exchange, new Gson().toJson(json));
-
-            return;
-        }
-
-        sendStringResponse(exchange, path);
-
-    }
-}

src/main/java/me/bobert/netneutrality/http/server/ActionRoutes.java

@@ -0,0 +1,82 @@
+package me.bobert.netneutrality.http.server;
+
+/*
+ * Copyright (c) anthorob
+ *
+ * https://discord.gg/qUa6zNFZsd
+ */
+
+import io.javalin.Javalin;
+import io.javalin.http.Handler;
+import me.bobert.netneutrality.db.service.GuildServiceProvider;
+import net.dv8tion.jda.api.JDA;
+import net.dv8tion.jda.api.entities.Guild;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.util.Map;
+import java.util.function.Supplier;
+
+/**
+ * Registers the {@code /actions/*} endpoints on a {@link Javalin} instance.
+ */
+public final class ActionRoutes {
+
+    private static final Logger logger = LogManager.getLogger(ActionRoutes.class);
+    private static final long SHUTDOWN_DELAY_MILLIS = 500;
+
+    private ActionRoutes() {
+    }
+
+    public static void register(
+        Javalin app,
+        Supplier<JDA> jdaSupplier,
+        GuildServiceProvider guildServices,
+        Runnable shutdownHook
+    ) {
+        app.get("/actions/status", ctx -> {
+            JDA jda = GuildRoutes.jda(jdaSupplier);
+            ctx.json(Map.of(
+                "health", String.valueOf(jda.getStatus()),
+                "ping", String.valueOf(jda.getGatewayPing())
+            ));
+        });
+
+        Handler shutdown = ctx -> {
+            logger.info("Request to shutdown received");
+            ctx.result("Shutting down..");
+            scheduleShutdown(shutdownHook);
+        };
+        app.post("/actions/shutdown", shutdown);
+        app.get("/actions/shutdown", shutdown);
+
+        app.get("/actions/settings/current/{guildId}", ctx -> {
+            Guild guild = GuildRoutes.guild(jdaSupplier, ctx);
+            Map<String, String> settings = guildServices.get(guild).getGuildSettingService().getSettings();
+
+            ctx.json(Map.of("status", "ok", "settings", settings));
+        });
+
+        app.post("/actions/settings/reload/{guildId}", ctx -> {
+            Guild guild = GuildRoutes.guild(jdaSupplier, ctx);
+            guildServices.get(guild).getGuildSettingService().reloadSettingsCache();
+
+            ctx.json(Map.of("status", "true"));
+        });
+    }
+
+    /**
+     * Runs the shutdown hook off the request thread so the response can be flushed first.
+     */
+    private static void scheduleShutdown(Runnable shutdownHook) {
+        Thread.ofPlatform().name("web-api-shutdown").start(() -> {
+            try {
+                Thread.sleep(SHUTDOWN_DELAY_MILLIS);
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt();
+            }
+            shutdownHook.run();
+            System.exit(0);
+        });
+    }
+}

src/main/java/me/bobert/netneutrality/http/server/GsonJsonMapper.java

@@ -0,0 +1,33 @@
+package me.bobert.netneutrality.http.server;
+
+/*
+ * Copyright (c) anthorob
+ *
+ * https://discord.gg/qUa6zNFZsd
+ */
+
+import com.google.gson.Gson;
+import io.javalin.json.JsonMapper;
+import org.jetbrains.annotations.NotNull;
+
+import java.lang.reflect.Type;
+
+/**
+ * Javalin {@link JsonMapper} backed by a shared {@link Gson} instance.
+ */
+public class GsonJsonMapper implements JsonMapper {
+
+    private static final Gson GSON = new Gson();
+
+    @NotNull
+    @Override
+    public String toJsonString(@NotNull Object obj, @NotNull Type type) {
+        return GSON.toJson(obj, type);
+    }
+
+    @NotNull
+    @Override
+    public <T> T fromJsonString(@NotNull String json, @NotNull Type targetType) {
+        return GSON.fromJson(json, targetType);
+    }
+}

src/main/java/me/bobert/netneutrality/http/server/GuildHandler.java

@@ -1,100 +0,0 @@
-package me.bobert.netneutrality.http.server;
-
-/*
- * Copyright (c) anthorob
- *
- * https://discord.gg/qUa6zNFZsd
- */
-
-import com.sun.net.httpserver.HttpExchange;
-import net.dv8tion.jda.api.JDA;
-import org.json.JSONArray;
-import org.json.JSONObject;
-
-import java.io.IOException;
-import java.util.Objects;
-import java.util.function.Supplier;
-
-public class GuildHandler extends AbstractHandler {
-    private final Supplier<JDA> jdaSupplier;
-
-    public GuildHandler(Supplier<JDA> jdaSupplier) {
-        this.jdaSupplier = Objects.requireNonNull(jdaSupplier, "jdaSupplier");
-    }
-
-    @Override
-    public void handle(HttpExchange exchange) throws IOException {
-
-        String path = exchange.getRequestURI().getRawPath();
-
-        if (path.equals("/guilds/owner")) {
-
-            JSONArray array = new JSONArray();
-
-            JDA jda = jdaSupplier.get();
-
-            jda.getGuilds().forEach(guild -> {
-                JSONObject obj = new JSONObject();
-                obj.put("guild_id", guild.getId());
-                obj.put("owner_id", guild.getOwnerId());
-                array.put(obj);
-            });
-
-            sendJsonResponse(exchange, array.toString());
-            return;
-
-        }
-
-        if (path.startsWith("/guilds/channels/")) {
-
-            String[] args = exchange.getRequestURI().toString().split("/");
-            String guild = args[args.length - 1];
-            JSONArray array = new JSONArray();
-
-            JDA jda = jdaSupplier.get();
-
-            if (jda.getGuildById(guild) == null) {
-                sendStringResponse(exchange, path);
-                return;
-            }
-
-            jda.getGuildById(guild).getTextChannels().forEach(channel -> {
-                JSONObject obj = new JSONObject();
-                obj.put("channel_id", channel.getId());
-                obj.put("channel_name", channel.getName());
-                array.put(obj);
-            });
-
-            sendJsonResponse(exchange, array.toString());
-            return;
-
-        }
-
-        if (path.startsWith("/guilds/roles/")) {
-
-            String[] args = exchange.getRequestURI().toString().split("/");
-            String guild = args[args.length - 1];
-            JSONArray array = new JSONArray();
-            JDA jda = jdaSupplier.get();
-
-            if (jda.getGuildById(guild) == null) {
-                sendStringResponse(exchange, path);
-                return;
-            }
-
-            jda.getGuildById(guild).getRoles().forEach(role -> {
-                JSONObject obj = new JSONObject();
-                obj.put("channel_id", role.getId());
-                obj.put("channel_name", role.getName());
-                array.put(obj);
-            });
-
-            sendJsonResponse(exchange, array.toString());
-            return;
-
-        }
-
-        sendStringResponse(exchange, path);
-
-    }
-}

src/main/java/me/bobert/netneutrality/http/server/GuildRoutes.java

@@ -0,0 +1,79 @@
+package me.bobert.netneutrality.http.server;
+
+/*
+ * Copyright (c) anthorob
+ *
+ * https://discord.gg/qUa6zNFZsd
+ */
+
+import io.javalin.Javalin;
+import io.javalin.http.Context;
+import io.javalin.http.NotFoundResponse;
+import io.javalin.http.ServiceUnavailableResponse;
+import net.dv8tion.jda.api.JDA;
+import net.dv8tion.jda.api.entities.Guild;
+
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.function.Supplier;
+
+/**
+ * Registers the read-only {@code /guilds/*} endpoints on a {@link Javalin} instance.
+ */
+public final class GuildRoutes {
+
+    private GuildRoutes() {
+    }
+
+    public static void register(Javalin app, Supplier<JDA> jdaSupplier) {
+        app.get("/guilds/owner", ctx -> ctx.json(
+            jda(jdaSupplier).getGuilds().stream()
+                .map(guild -> ordered("guild_id", guild.getId(), "owner_id", guild.getOwnerId()))
+                .toList()
+        ));
+
+        app.get("/guilds/channels/{guildId}", ctx -> ctx.json(
+            guild(jdaSupplier, ctx).getTextChannels().stream()
+                .map(channel -> ordered("channel_id", channel.getId(), "channel_name", channel.getName()))
+                .toList()
+        ));
+
+        app.get("/guilds/roles/{guildId}", ctx -> ctx.json(
+            guild(jdaSupplier, ctx).getRoles().stream()
+                .map(role -> ordered("channel_id", role.getId(), "channel_name", role.getName()))
+                .toList()
+        ));
+    }
+
+    /**
+     * Builds a two entry map with a stable key order for JSON serialization.
+     */
+    private static Map<String, String> ordered(String firstKey, String firstValue, String secondKey, String secondValue) {
+        Map<String, String> map = new LinkedHashMap<>();
+        map.put(firstKey, firstValue);
+        map.put(secondKey, secondValue);
+        return map;
+    }
+
+    /**
+     * Resolves the JDA client or fails with 503 while it is not ready yet.
+     */
+    static JDA jda(Supplier<JDA> jdaSupplier) {
+        JDA jda = jdaSupplier.get();
+        if (jda == null) {
+            throw new ServiceUnavailableResponse("Discord client is not ready");
+        }
+        return jda;
+    }
+
+    /**
+     * Resolves the {@code guildId} path parameter or fails with 404.
+     */
+    static Guild guild(Supplier<JDA> jdaSupplier, Context ctx) {
+        Guild guild = jda(jdaSupplier).getGuildById(ctx.pathParam("guildId"));
+        if (guild == null) {
+            throw new NotFoundResponse("Unknown guild");
+        }
+        return guild;
+    }
+}

src/main/java/me/bobert/netneutrality/http/server/RootHandler.java

@@ -1,22 +0,0 @@
-package me.bobert.netneutrality.http.server;
-
-/*
- * Copyright (c) anthorob
- *
- * https://discord.gg/qUa6zNFZsd
- */
-
-import com.sun.net.httpserver.HttpExchange;
-
-import java.io.IOException;
-
-public class RootHandler extends AbstractHandler {
-
-    @Override
-    public void handle(HttpExchange exchange) throws IOException {
-
-        String response = "<h1>Server start success if you see this message</h1>";
-
-        sendStringResponse(exchange, response);
-    }
-}

src/main/java/me/bobert/netneutrality/http/server/WebApi.java

@@ -6,20 +6,16 @@ package me.bobert.netneutrality.http.server;
  * https://discord.gg/qUa6zNFZsd
  */
 
-import com.sun.net.httpserver.HttpServer;
+import io.javalin.Javalin;
+import io.javalin.http.HttpResponseException;
 import me.bobert.netneutrality.bootstrap.Lifecycle;
-import me.bobert.netneutrality.core.thread.BaseThreadFactory;
 import me.bobert.netneutrality.db.service.GuildServiceProvider;
 import me.bobert.netneutrality.utils.SettingsProvider;
 import net.dv8tion.jda.api.JDA;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
-import java.io.IOException;
-import java.net.InetSocketAddress;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-import java.util.function.IntSupplier;
+import java.util.Map;
 import java.util.function.Supplier;
 
 /**
@@ -28,13 +24,13 @@ import java.util.function.Supplier;
 public class WebApi implements Lifecycle {
 
     private static final Logger logger = LogManager.getLogger(WebApi.class);
+    private static final String LIVENESS_HTML = "<h1>Server start success if you see this message</h1>";
 
     private final SettingsProvider settings;
     private final GuildServiceProvider guildServices;
     private final Supplier<JDA> jdaSupplier;
     private final Runnable shutdownHook;
-    private HttpServer server;
-    private ExecutorService executor;
+    private Javalin app;
 
     public WebApi(
         SettingsProvider settings,
@@ -59,33 +55,36 @@ public class WebApi implements Lifecycle {
         int port = Integer.parseInt(settings.get("NETNEUTRALITY_API_PORT", "9000"));
         logger.info("Starting web server...");
 
-        try {
-            InetSocketAddress sockAddr = new InetSocketAddress(port);
-            server = HttpServer.create(sockAddr, 0);
-        } catch (IOException e) {
-            logger.error("Failed to create HTTP server", e);
-            return;
-        }
+        app = Javalin.create(config -> {
+            config.jsonMapper(new GsonJsonMapper());
+            config.showJavalinBanner = false;
+        });
 
-        server.createContext("/", new RootHandler());
-        server.createContext("/actions", new ActionHandler(jdaSupplier, guildServices, shutdownHook));
-        server.createContext("/guilds", new GuildHandler(jdaSupplier));
-        executor = Executors.newFixedThreadPool(10, new BaseThreadFactory("web-api"));
-        server.setExecutor(executor);
-        server.start();
-        logger.info("Web server started at [{}]", server.getAddress());
+        app.get("/", ctx -> ctx.html(LIVENESS_HTML));
+        GuildRoutes.register(app, jdaSupplier);
+        ActionRoutes.register(app, jdaSupplier, guildServices, shutdownHook);
+
+        app.exception(HttpResponseException.class, (e, ctx) ->
+            ctx.status(e.getStatus()).json(Map.of("status", "error", "message", e.getMessage()))
+        );
+
+        app.exception(Exception.class, (e, ctx) -> {
+            logger.error("Unhandled error while serving [{}]", ctx.path(), e);
+            ctx.status(500).json(Map.of("status", "error"));
+        });
+
+        app.error(404, ctx -> ctx.json(Map.of("status", "error", "message", "Not found")));
+
+        app.start(port);
+        logger.info("Web server started on port [{}]", port);
     }
 
     @Override
     public void stop() {
-        if (server != null) {
+        if (app != null) {
             logger.info("Stopping web server...");
-            server.stop(0);
-            server = null;
-        }
-        if (executor != null) {
-            executor.shutdownNow();
-            executor = null;
+            app.stop();
+            app = null;
         }
     }
 }

src/test/java/me/bobert/netneutrality/http/WebModuleTest.java

@@ -0,0 +1,88 @@
+package me.bobert.netneutrality.http;
+
+/*
+ * Copyright (c) anthorob
+ *
+ * https://discord.gg/qUa6zNFZsd
+ */
+
+import io.javalin.Javalin;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.util.Map;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+class WebModuleTest {
+
+    private Javalin server;
+    private int port;
+    private final AtomicInteger hits = new AtomicInteger();
+
+    @BeforeEach
+    void setUp() {
+        server = Javalin.create(config -> config.showJavalinBanner = false);
+        server.get("/counter", ctx -> ctx.result("{\"hits\":" + hits.incrementAndGet() + "}"));
+        server.post("/counter", ctx -> ctx.result("{\"hits\":" + hits.incrementAndGet() + "}"));
+        server.start(0);
+        port = server.port();
+    }
+
+    @AfterEach
+    void tearDown() {
+        server.stop();
+    }
+
+    @Test
+    void getRequestsAreServedFromTheCache() {
+        String url = url("cache-hit");
+
+        assertEquals(1, new WebModule.Builder(url).get().cache(1, TimeUnit.MINUTES).build().request()
+            .getAsObject().getInt("hits"));
+        assertEquals(1, new WebModule.Builder(url).get().cache(1, TimeUnit.MINUTES).build().request()
+            .getAsObject().getInt("hits"));
+
+        assertEquals(1, hits.get());
+    }
+
+    @Test
+    void expiredEntriesAreRefetched() throws Exception {
+        String url = url("cache-expiry");
+
+        new WebModule.Builder(url).get().cache(1, TimeUnit.MILLISECONDS).build().request();
+        Thread.sleep(20);
+        new WebModule.Builder(url).get().cache(1, TimeUnit.MILLISECONDS).build().request();
+
+        assertEquals(2, hits.get());
+    }
+
+    @Test
+    void invalidateCacheForcesANewRequest() {
+        String url = url("cache-invalidate");
+
+        new WebModule.Builder(url).get().cache(1, TimeUnit.MINUTES).build().request();
+        WebModule.invalidateCache(url);
+        new WebModule.Builder(url).get().cache(1, TimeUnit.MINUTES).build().request();
+
+        assertEquals(2, hits.get());
+    }
+
+    @Test
+    void postRequestsBypassTheCache() {
+        String url = url("cache-post");
+
+        assertTrue(new WebModule.Builder(url).post(Map.of("a", "b")).build().request().isSuccess());
+        new WebModule.Builder(url).post(Map.of("a", "b")).build().request();
+
+        assertEquals(2, hits.get());
+    }
+
+    private String url(String marker) {
+        return "http://localhost:" + port + "/counter?marker=" + marker + "-" + System.nanoTime();
+    }
+}

src/test/java/me/bobert/netneutrality/http/server/WebApiTest.java

@@ -0,0 +1,172 @@
+package me.bobert.netneutrality.http.server;
+
+/*
+ * Copyright (c) anthorob
+ *
+ * https://discord.gg/qUa6zNFZsd
+ */
+
+import me.bobert.netneutrality.db.service.GuildService;
+import me.bobert.netneutrality.db.service.GuildServiceProvider;
+import me.bobert.netneutrality.db.service.GuildSettingService;
+import me.bobert.netneutrality.utils.SettingsProvider;
+import net.dv8tion.jda.api.JDA;
+import net.dv8tion.jda.api.entities.Guild;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.util.List;
+import java.util.Map;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+class WebApiTest {
+
+    private static final String GUILD_ID = "1234567890";
+
+    private WebApi webApi;
+    private int port;
+    private GuildSettingService settingService;
+    private final HttpClient http = HttpClient.newHttpClient();
+
+    @BeforeEach
+    void setUp() throws IOException {
+        port = freePort();
+
+        Guild guild = mock(Guild.class);
+        when(guild.getId()).thenReturn(GUILD_ID);
+        when(guild.getOwnerId()).thenReturn("42");
+
+        JDA jda = mock(JDA.class);
+        when(jda.getGuilds()).thenReturn(List.of(guild));
+        when(jda.getGuildById(GUILD_ID)).thenReturn(guild);
+        when(jda.getGuildById(any(String.class))).thenAnswer(inv ->
+            GUILD_ID.equals(inv.getArgument(0)) ? guild : null);
+        when(jda.getStatus()).thenReturn(JDA.Status.CONNECTED);
+        when(jda.getGatewayPing()).thenReturn(12L);
+
+        settingService = mock(GuildSettingService.class);
+        when(settingService.getSettings()).thenReturn(Map.of("prefix", "ü!"));
+
+        GuildService guildService = mock(GuildService.class);
+        when(guildService.getGuildSettingService()).thenReturn(settingService);
+
+        GuildServiceProvider provider = mock(GuildServiceProvider.class);
+        when(provider.get(guild)).thenReturn(guildService);
+
+        SettingsProvider settings = mock(SettingsProvider.class);
+        when(settings.get("NETNEUTRALITY_API_PORT", "9000")).thenReturn(String.valueOf(port));
+
+        webApi = new WebApi(settings, provider, () -> jda, () -> { });
+        webApi.start();
+    }
+
+    @AfterEach
+    void tearDown() {
+        webApi.stop();
+    }
+
+    @Test
+    void rootReturnsLivenessHtml() throws Exception {
+        HttpResponse<String> response = get("/");
+
+        assertEquals(200, response.statusCode());
+        assertTrue(response.body().contains("Server start success"));
+    }
+
+    @Test
+    void statusReturnsHealthAndPing() throws Exception {
+        HttpResponse<String> response = get("/actions/status");
+
+        assertEquals(200, response.statusCode());
+        assertTrue(response.body().contains("\"health\":\"CONNECTED\""));
+        assertTrue(response.body().contains("\"ping\":\"12\""));
+    }
+
+    @Test
+    void ownerReturnsGuildOwners() throws Exception {
+        HttpResponse<String> response = get("/guilds/owner");
+
+        assertEquals(200, response.statusCode());
+        assertEquals("[{\"guild_id\":\"" + GUILD_ID + "\",\"owner_id\":\"42\"}]", response.body());
+    }
+
+    @Test
+    void currentSettingsAreReturnedForKnownGuild() throws Exception {
+        HttpResponse<String> response = get("/actions/settings/current/" + GUILD_ID);
+
+        assertEquals(200, response.statusCode());
+        assertTrue(response.body().contains("\"status\":\"ok\""));
+        assertTrue(response.body().contains("ü!"));
+    }
+
+    @Test
+    void unknownGuildReturnsNotFound() throws Exception {
+        HttpResponse<String> response = get("/guilds/channels/999");
+
+        assertEquals(404, response.statusCode());
+        assertTrue(response.body().contains("\"status\":\"error\""));
+    }
+
+    @Test
+    void unknownPathReturnsNotFound() throws Exception {
+        assertEquals(404, get("/nope").statusCode());
+    }
+
+    @Test
+    void wrongMethodIsNotRouted() throws Exception {
+        HttpRequest request = HttpRequest.newBuilder(uri("/guilds/owner"))
+            .POST(HttpRequest.BodyPublishers.noBody())
+            .build();
+
+        assertEquals(404, http.send(request, HttpResponse.BodyHandlers.ofString()).statusCode());
+    }
+
+    @Test
+    void reloadRefreshesTheSettingCache() throws Exception {
+        HttpRequest request = HttpRequest.newBuilder(uri("/actions/settings/reload/" + GUILD_ID))
+            .POST(HttpRequest.BodyPublishers.noBody())
+            .build();
+        HttpResponse<String> response = http.send(request, HttpResponse.BodyHandlers.ofString());
+
+        assertEquals(200, response.statusCode());
+        assertTrue(response.body().contains("\"status\":\"true\""));
+        verify(settingService).reloadSettingsCache();
+    }
+
+    @Test
+    void stopReleasesThePort() throws Exception {
+        webApi.stop();
+
+        try (ServerSocket socket = new ServerSocket(port)) {
+            assertEquals(port, socket.getLocalPort());
+        }
+    }
+
+    private HttpResponse<String> get(String path) throws Exception {
+        HttpRequest request = HttpRequest.newBuilder(uri(path)).GET().build();
+        return http.send(request, HttpResponse.BodyHandlers.ofString());
+    }
+
+    private URI uri(String path) {
+        return URI.create("http://localhost:" + port + path);
+    }
+
+    private static int freePort() throws IOException {
+        try (ServerSocket socket = new ServerSocket(0)) {
+            return socket.getLocalPort();
+        }
+    }
+}