Migrate from Gson and org.json to Jackson

Replaced Gson and org.json usage across the codebase with a unified Jackson-based implementation through a shared `Json` utility. Updated all JSON serialization and deserialization logic (`GsonJsonMapper`, HTTP client, task persistence, command handling, tests) to use Jackson's `ObjectMapper`. Removed the outdated dependencies from `pom.xml` and verified symmetry in payload serialization.

src/main/java/me/bobert/netneutrality/bootstrap/BotState.java

@@ -5,13 +5,14 @@ package me.bobert.netneutrality.bootstrap;
  * https://discord.gg/qUa6zNFZsd
  */
 
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import me.bobert.netneutrality.db.service.GuildServiceProvider;
 import me.bobert.netneutrality.db.service.GuildService;
 import me.bobert.netneutrality.music.MusicService;
 import me.bobert.netneutrality.music.MusicManager;
 import me.bobert.netneutrality.music.TrackScheduler;
-import org.json.JSONArray;
-import org.json.JSONObject;
+import me.bobert.netneutrality.utils.Json;
 
 import java.io.File;
 import java.io.FileWriter;
@@ -43,8 +44,8 @@ public class BotState {
 
         Map<String, GuildService> services = guildServices.getServices();
 
-        JSONObject main = new JSONObject();
-        JSONArray guildsArray = new JSONArray();
+        ObjectNode main = Json.object();
+        ArrayNode guildsArray = Json.array();
 
         for (MusicManager manager : musicService.getManagers()) {
             TrackScheduler trackScheduler = manager.getScheduler();
@@ -53,8 +54,8 @@ public class BotState {
         for (GuildService service : services.values()) {
 
 
-            JSONObject guild = new JSONObject();
-            JSONObject music = new JSONObject();
+            ObjectNode guild = Json.object();
+            ObjectNode music = Json.object();
             guild.put("id", service.getEntity().getGuildId());
 
 //            MessageChannel currentChannel = trackScheduler.getTextChannel();
@@ -64,12 +65,12 @@ public class BotState {
 //                music.put("current_channel", currentChannel.getId());
 //            }
 
-            guild.put("music", music);
+            guild.set("music", music);
 
-            guildsArray.put(guild);
+            guildsArray.add(guild);
         }
 
-        main.put("guilds", guildsArray);
+        main.set("guilds", guildsArray);
 
         File state = new File("state.json");
         try {

src/main/java/me/bobert/netneutrality/command/crypto/CryptoPriceCommand.java

@@ -5,6 +5,8 @@ package me.bobert.netneutrality.command.crypto;
  * https://discord.gg/qUa6zNFZsd
  */
 
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import me.bobert.netneutrality.core.LogHandler;
 import me.bobert.netneutrality.core.command.CommandCategory;
 import me.bobert.netneutrality.core.command.CommandExecutionResult;
@@ -15,7 +17,6 @@ import me.bobert.netneutrality.core.context.CommandContext;
 import me.bobert.netneutrality.http.WebModule;
 import net.dv8tion.jda.api.interactions.commands.OptionType;
 import net.dv8tion.jda.api.interactions.commands.build.OptionData;
-import org.json.JSONObject;
 
 import java.text.NumberFormat;
 import java.util.Currency;
@@ -91,14 +92,19 @@ public class CryptoPriceCommand extends AbstractCommand {
                 }
 
                 WebModule http = new WebModule.Builder(String.format(baseURL, symbol, finalCurrency)).cache(30, TimeUnit.MINUTES).build().request();
-                JSONObject json = http.getAsObject();
+                ObjectNode json = http.getAsObject();
 
-                if (json.isEmpty() || (json.has("Response") && json.getString("Response").equalsIgnoreCase("Error"))) {
+                if (json.isEmpty() || json.path("Response").asText("").equalsIgnoreCase("Error")) {
                     asyncMessage.edit("Crypto doesn't exist.. yet");
                     return;
                 }
 
-                double value = json.getDouble(finalCurrency);
+                JsonNode priceNode = json.path(finalCurrency);
+                if (!priceNode.isNumber()) {
+                    throw new IllegalStateException("Missing price for currency " + finalCurrency);
+                }
+
+                double value = priceNode.asDouble();
                 String price = dollarFormat.format(value);
 
                 asyncMessage.edit(String.format("The current price of %s in %s is %s", symbol, finalCurrency, price));
@@ -115,12 +121,12 @@ public class CryptoPriceCommand extends AbstractCommand {
     private boolean validateSymbol(String symbol) {
         try {
             WebModule http = new WebModule.Builder(exchangeApi).get().cache(1, TimeUnit.DAYS).build().request();
-            JSONObject json = http.getAsObject();
+            ObjectNode json = http.getAsObject();
 
-            JSONObject pairs = json.getJSONObject("Data")
-                .getJSONObject("exchanges")
-                .getJSONObject(exchange)
-                .getJSONObject("pairs");
+            JsonNode pairs = json.path("Data")
+                .path("exchanges")
+                .path(exchange)
+                .path("pairs");
 
             return pairs.has(symbol);
 

src/main/java/me/bobert/netneutrality/core/tasks/PersistableTask.java

@@ -5,8 +5,8 @@ package me.bobert.netneutrality.core.tasks;
  * https://discord.gg/qUa6zNFZsd
  */
 
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import me.bobert.netneutrality.core.context.CommandContext;
-import org.json.JSONObject;
 
 /**
  * Represents a task that can be persisted and restored later.
@@ -29,7 +29,7 @@ public interface PersistableTask extends Task {
      *
      * @param payload the persisted payload, must not be {@code null}
      */
-    void restore(JSONObject payload);
+    void restore(ObjectNode payload);
 
     void insert(CommandContext context);
 

src/main/java/me/bobert/netneutrality/core/tasks/impl/AbstractPersistableTask.java

@@ -5,10 +5,11 @@ package me.bobert.netneutrality.core.tasks.impl;
  * https://discord.gg/qUa6zNFZsd
  */
 
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import me.bobert.netneutrality.core.context.CommandContext;
 import me.bobert.netneutrality.core.tasks.PersistableTask;
 import me.bobert.netneutrality.core.tasks.TaskManager;
-import org.json.JSONObject;
+import me.bobert.netneutrality.utils.Json;
 
 public abstract class AbstractPersistableTask extends AbstractTask implements PersistableTask {
 
@@ -66,15 +67,27 @@ public abstract class AbstractPersistableTask extends AbstractTask implements Pe
      * @param payload the persisted payload
      */
     @Override
-    public void restore(JSONObject payload) {
+    public void restore(ObjectNode payload) {
         // Nothing to restore by default
     }
 
+    /**
+     * No-op default: only tasks carrying extra state need to override this.
+     *
+     * @param payload the payload being written
+     */
+    protected void writePayload(ObjectNode payload) {
+        // Nothing extra to write by default
+    }
+
     @Override
     public String toPayload() {
-        JSONObject payload = new JSONObject(this);
+        ObjectNode payload = Json.object();
         payload.put("id", getId());
         payload.put("lockId", getLockId());
+        payload.put("name", getName());
+
+        writePayload(payload);
 
         return payload.toString();
     }

src/main/java/me/bobert/netneutrality/core/tasks/impl/EmojiTask.java

@@ -5,9 +5,10 @@ package me.bobert.netneutrality.core.tasks.impl;
  * https://discord.gg/qUa6zNFZsd
  */
 
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import me.bobert.netneutrality.context.tasks.EmojiTaskContext;
 import me.bobert.netneutrality.core.tasks.TaskManager;
-import org.json.JSONObject;
 
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
@@ -27,7 +28,7 @@ public abstract class EmojiTask extends AbstractPersistableTask {
 
     /**
      * Constructor used by the persistable task registry: the message coordinates and the emoji
-     * mapping are hydrated afterwards by {@link #restore(JSONObject)}.
+     * mapping are hydrated afterwards by {@link #restore(ObjectNode)}.
      *
      * @param taskManager the application task manager, must not be {@code null}
      */
@@ -36,17 +37,31 @@ public abstract class EmojiTask extends AbstractPersistableTask {
     }
 
     @Override
-    public void restore(JSONObject payload) {
-        this.guildId = payload.optString("guildId", null);
-        this.channelId = payload.optString("channelId", null);
-        this.messageId = payload.optString("messageId", null);
+    public void restore(ObjectNode payload) {
+        this.guildId = payload.path("guildId").asText(null);
+        this.channelId = payload.path("channelId").asText(null);
+        this.messageId = payload.path("messageId").asText(null);
 
         emojiMapping.clear();
-        JSONObject mapping = payload.optJSONObject("emojiMapping");
-        if (mapping != null) {
-            for (String emoji : mapping.keySet()) {
-                emojiMapping.put(emoji, mapping.getString(emoji));
-            }
+        JsonNode mapping = payload.path("emojiMapping");
+        if (mapping.isObject()) {
+            mapping.properties().forEach(entry -> emojiMapping.put(entry.getKey(), entry.getValue().asText()));
+        }
+    }
+
+    @Override
+    protected void writePayload(ObjectNode payload) {
+        putIfPresent(payload, "guildId", guildId);
+        putIfPresent(payload, "channelId", channelId);
+        putIfPresent(payload, "messageId", messageId);
+
+        ObjectNode mapping = payload.putObject("emojiMapping");
+        emojiMapping.forEach(mapping::put);
+    }
+
+    private static void putIfPresent(ObjectNode payload, String key, String value) {
+        if (value != null) {
+            payload.put(key, value);
         }
     }
 

src/main/java/me/bobert/netneutrality/core/tasks/persistence/PersistableTaskRegistry.java

@@ -5,12 +5,12 @@ package me.bobert.netneutrality.core.tasks.persistence;
  * https://discord.gg/qUa6zNFZsd
  */
 
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import me.bobert.netneutrality.bootstrap.ApplicationContext;
 import me.bobert.netneutrality.bootstrap.ReflectionHelper;
 import me.bobert.netneutrality.core.tasks.PersistableTask;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.json.JSONObject;
 
 import java.util.Collections;
 import java.util.Map;
@@ -88,7 +88,7 @@ public final class PersistableTaskRegistry {
      * @throws IllegalArgumentException if no task type is registered under {@code typeId}
      * @throws ReflectiveOperationException if the task type cannot be instantiated
      */
-    public PersistableTask create(String typeId, JSONObject payload) throws ReflectiveOperationException {
+    public PersistableTask create(String typeId, ObjectNode payload) throws ReflectiveOperationException {
         Class<? extends PersistableTask> type = typesById.get(typeId);
         if (type == null) {
             throw new IllegalArgumentException("No persistable task type registered for id: " + typeId);

src/main/java/me/bobert/netneutrality/db/service/TaskService.java

@@ -5,14 +5,15 @@ package me.bobert.netneutrality.db.service;
  * https://discord.gg/qUa6zNFZsd
  */
 
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import me.bobert.netneutrality.core.tasks.PersistableTask;
 import me.bobert.netneutrality.core.tasks.TaskManager;
 import me.bobert.netneutrality.core.tasks.persistence.PersistableTaskRegistry;
 import me.bobert.netneutrality.db.entities.OTask;
 import me.bobert.netneutrality.db.repository.TaskRepository;
+import me.bobert.netneutrality.utils.Json;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.json.JSONObject;
 
 import java.util.List;
 import java.util.Objects;
@@ -42,7 +43,7 @@ public class TaskService {
             String payload = oTask.getPayload();
 
             try {
-                JSONObject json = new JSONObject(payload);
+                ObjectNode json = Json.readObject(payload);
                 PersistableTask task = registry.create(typeId, json);
 
                 validateTask(task, oTask);
@@ -61,13 +62,13 @@ public class TaskService {
             throw new IllegalArgumentException("Task ID mismatch, expected: " + task.getId());
         }
 
-        JSONObject json = new JSONObject(payload);
-        String payloadId = json.getString("id");
+        ObjectNode json = Json.readObject(payload);
+        String payloadId = json.path("id").asText(null);
         if (!Objects.equals(payloadId, task.getId())) {
             throw new IllegalArgumentException("Task payload ID mismatch, expected: " + task.getId());
         }
 
-        String payloadLockId = json.getString("lockId");
+        String payloadLockId = json.path("lockId").asText(null);
         if (!Objects.equals(payloadLockId, task.getLockId())) {
             throw new IllegalArgumentException("Task lock ID mismatch, expected: " + task.getLockId());
         }

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

@@ -6,17 +6,17 @@ package me.bobert.netneutrality.http;
  * https://discord.gg/qUa6zNFZsd
  */
 
-import com.google.gson.Gson;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import io.sentry.Breadcrumb;
 import io.sentry.Sentry;
 import me.bobert.netneutrality.http.ResponseCache.CachedResponse;
+import me.bobert.netneutrality.utils.Json;
 import okhttp3.MediaType;
 import okhttp3.OkHttpClient;
 import okhttp3.Request;
 import okhttp3.RequestBody;
 import okhttp3.Response;
-import org.json.JSONArray;
-import org.json.JSONObject;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -130,15 +130,15 @@ public class WebModule {
         return keyBuilder.toString();
     }
 
-    public JSONObject getAsObject() {
+    public ObjectNode getAsObject() {
         return cachedResponse.getBody()
-            .map(JSONObject::new)
+            .map(Json::readObject)
             .orElseThrow(() -> new IllegalStateException("No body available for this response"));
     }
 
-    public JSONArray getAsArray() {
+    public ArrayNode getAsArray() {
         return cachedResponse.getBody()
-            .map(JSONArray::new)
+            .map(Json::readArray)
             .orElseThrow(() -> new IllegalStateException("No body available for this response"));
     }
 
@@ -253,7 +253,7 @@ public class WebModule {
             }
 
             if (method == Method.POST && !params.isEmpty()) {
-                RequestBody body = RequestBody.create(new Gson().toJson(params), MediaType.parse("application/json; charset=utf-8"));
+                RequestBody body = RequestBody.create(Json.write(params), MediaType.parse("application/json; charset=utf-8"));
                 builder.post(body);
             }
 

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

@@ -1,33 +0,0 @@
-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/WebApi.java

@@ -57,7 +57,6 @@ public class WebApi implements Lifecycle {
 
         // Javalin 7 requires routes, exception and error handlers to be registered upfront.
         app = Javalin.create(config -> {
-            config.jsonMapper(new GsonJsonMapper());
             config.startup.showJavalinBanner = false;
 
             config.routes.get("/", ctx -> ctx.html(LIVENESS_HTML));

src/main/java/me/bobert/netneutrality/utils/Json.java

@@ -0,0 +1,99 @@
+package me.bobert.netneutrality.utils;
+
+/*
+ * Copyright (c) anthorob
+ *
+ * https://discord.gg/qUa6zNFZsd
+ */
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+
+/**
+ * Process-wide JSON entry point backed by a single shared {@link ObjectMapper}.
+ */
+public final class Json {
+
+    private static final ObjectMapper MAPPER = new ObjectMapper();
+
+    private Json() {
+    }
+
+    public static ObjectMapper mapper() {
+        return MAPPER;
+    }
+
+    public static ObjectNode object() {
+        return MAPPER.createObjectNode();
+    }
+
+    public static ArrayNode array() {
+        return MAPPER.createArrayNode();
+    }
+
+    /**
+     * Parses a JSON document expected to be an object.
+     *
+     * @param json the raw JSON document
+     * @return the parsed object node
+     * @throws JsonException if the document is malformed or is not an object
+     */
+    public static ObjectNode readObject(String json) {
+        JsonNode node = read(json);
+
+        if (!(node instanceof ObjectNode objectNode)) {
+            throw new JsonException("Expected a JSON object but got: " + node.getNodeType());
+        }
+
+        return objectNode;
+    }
+
+    /**
+     * Parses a JSON document expected to be an array.
+     *
+     * @param json the raw JSON document
+     * @return the parsed array node
+     * @throws JsonException if the document is malformed or is not an array
+     */
+    public static ArrayNode readArray(String json) {
+        JsonNode node = read(json);
+
+        if (!(node instanceof ArrayNode arrayNode)) {
+            throw new JsonException("Expected a JSON array but got: " + node.getNodeType());
+        }
+
+        return arrayNode;
+    }
+
+    public static JsonNode read(String json) {
+        try {
+            return MAPPER.readTree(json);
+        } catch (JsonProcessingException e) {
+            throw new JsonException("Cannot parse JSON document", e);
+        }
+    }
+
+    public static String write(Object value) {
+        try {
+            return MAPPER.writeValueAsString(value);
+        } catch (JsonProcessingException e) {
+            throw new JsonException("Cannot serialize value to JSON", e);
+        }
+    }
+
+    /**
+     * Unchecked wrapper around Jackson's checked processing exceptions.
+     */
+    public static class JsonException extends RuntimeException {
+        public JsonException(String message) {
+            super(message);
+        }
+
+        public JsonException(String message, Throwable cause) {
+            super(message, cause);
+        }
+    }
+}

src/main/java/me/bobert/netneutrality/utils/Settings.java

@@ -6,9 +6,9 @@ package me.bobert.netneutrality.utils;
  * https://discord.gg/qUa6zNFZsd
  */
 
+import com.fasterxml.jackson.databind.node.ArrayNode;
 import me.bobert.netneutrality.http.WebModule;
 import org.apache.logging.log4j.LogManager;
-import org.json.JSONArray;
 
 import java.io.File;
 import java.io.FileInputStream;
@@ -101,11 +101,11 @@ public class Settings implements SettingsProvider {
         String gitlabProjectId = "22";
         String latestReleaseUrl = String.format("%s/api/v4/projects/%s/releases/", gitlabHost, gitlabProjectId);
 
-        JSONArray json = new WebModule.Builder(latestReleaseUrl).cache(1, TimeUnit.DAYS).build().request().getAsArray();
-        if (json.isNull(0)) {
+        ArrayNode json = new WebModule.Builder(latestReleaseUrl).cache(1, TimeUnit.DAYS).build().request().getAsArray();
+        if (json.isEmpty() || !json.get(0).hasNonNull("tag_name")) {
             return "0.0.0";
         }
 
-        return json.getJSONObject(0).getString("tag_name");
+        return json.get(0).get("tag_name").asText();
     }
 }