fix: Vendor in fml ModMetadata parsing to avoid unnecessary classloading

Author: FalsePattern

src/deploader/java/com/falsepattern/deploader/DependencyLoaderImpl.java

@@ -40,8 +40,6 @@
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
-import cpw.mods.fml.common.MetadataCollection;
-import cpw.mods.fml.common.ModMetadata;
 import cpw.mods.fml.fpdeploader.SystemExitBypassHelper;
 
 import javax.swing.JFrame;
@@ -58,7 +56,6 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
-import java.lang.reflect.Field;
 import java.net.MalformedURLException;
 import java.net.URISyntaxException;
 import java.net.URL;
@@ -103,7 +100,7 @@ public class DependencyLoaderImpl {
     private static final Map<String, String> loadedModIdMods = new ConcurrentHashMap<>();
     private static final Set<String> remoteMavenRepositories = new ConcurrentSet<>();
     private static final Set<String> localMavenRepositories = new ConcurrentSet<>();
-    static final Logger LOG = LogManager.getLogger("FalsePatternLib DepLoader");
+    public static final Logger LOG = LogManager.getLogger("FalsePatternLib DepLoader");
 
     private static final AtomicLong counter = new AtomicLong(0);
     private static final ExecutorService executor = Executors.newCachedThreadPool(r -> {
@@ -115,21 +112,11 @@ public class DependencyLoaderImpl {
     private static final Path libDir;
     private static final Path modsDir;
     private static final Path tempDir;
-    private static final Field metadataCollectionModListAccessor;
 
     private static final AtomicBoolean needReboot = new AtomicBoolean(false);
     private static final Set<String> downloadedMods = new ConcurrentSet<>();
     private static final Set<String> downloadFailed = new ConcurrentSet<>();
 
-    static {
-        try {
-            metadataCollectionModListAccessor = MetadataCollection.class.getDeclaredField("modList");
-        } catch (NoSuchFieldException e) {
-            throw new RuntimeException(e);
-        }
-        metadataCollectionModListAccessor.setAccessible(true);
-    }
-
     private static void ensureExists(Path directory) {
         if (!Files.exists(directory)) {
             try {
@@ -300,8 +287,7 @@ public static CompletableFuture<Void> loadLibrariesAsync(Library... libraries) {
     private static void readMCMod(InputStream input, String name) {
         try {
             val meta = MetadataCollection.from(input, name);
-            val modList = (ModMetadata[]) metadataCollectionModListAccessor.get(meta);
-            for (val mod : modList) {
+            for (val mod : meta.modList) {
                 val id = mod.modId;
                 if (id != null) {
                     val versionStr = mod.version;

src/deploader/java/com/falsepattern/deploader/MetadataCollection.java

@@ -0,0 +1,97 @@
+/*
+ * This file is part of FalsePatternLib.
+ *
+ * Copyright (C) 2022-2025 FalsePattern
+ * All Rights Reserved
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * FalsePatternLib is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, only version 3 of the License.
+ *
+ * FalsePatternLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with FalsePatternLib. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.falsepattern.deploader;
+
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.Map;
+
+import com.google.common.base.Throwables;
+import com.google.common.collect.Maps;
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonArray;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonParseException;
+import com.google.gson.JsonParser;
+
+class MetadataCollection
+{
+    @SuppressWarnings("unused")
+    private String modListVersion;
+    ModMetadata[] modList;
+    private Map<String, ModMetadata> metadatas = Maps.newHashMap();
+
+    public static MetadataCollection from(InputStream inputStream, String sourceName)
+    {
+        if (inputStream == null)
+        {
+            return new MetadataCollection();
+        }
+
+        InputStreamReader reader = new InputStreamReader(inputStream);
+        try
+        {
+            MetadataCollection collection;
+            Gson gson = new GsonBuilder().create();
+            JsonParser parser = new JsonParser();
+            JsonElement rootElement = parser.parse(reader);
+            if (rootElement.isJsonArray())
+            {
+                collection = new MetadataCollection();
+                JsonArray jsonList = rootElement.getAsJsonArray();
+                collection.modList = new ModMetadata[jsonList.size()];
+                int i = 0;
+                for (JsonElement mod : jsonList)
+                {
+                    collection.modList[i++]=gson.fromJson(mod, ModMetadata.class);
+                }
+            }
+            else
+            {
+                collection = gson.fromJson(rootElement, MetadataCollection.class);
+            }
+            collection.parseModMetadataList();
+            return collection;
+        }
+        catch (JsonParseException e)
+        {
+            DependencyLoaderImpl.LOG.error(e);
+            DependencyLoaderImpl.LOG.error("The mcmod.info file in {} cannot be parsed as valid JSON. It will be ignored", sourceName);
+            return new MetadataCollection();
+        }
+        catch (Exception e)
+        {
+            throw Throwables.propagate(e);
+        }
+    }
+
+
+    private void parseModMetadataList()
+    {
+        for (ModMetadata modMetadata : modList)
+        {
+            metadatas.put(modMetadata.modId, modMetadata);
+        }
+    }
+}

src/deploader/java/com/falsepattern/deploader/ModMetadata.java

@@ -0,0 +1,41 @@
+/*
+ * This file is part of FalsePatternLib.
+ *
+ * Copyright (C) 2022-2025 FalsePattern
+ * All Rights Reserved
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * FalsePatternLib is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, only version 3 of the License.
+ *
+ * FalsePatternLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with FalsePatternLib. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.falsepattern.deploader;
+
+import com.google.gson.annotations.SerializedName;
+
+/**
+ * @author cpw
+ *
+ */
+class ModMetadata
+{
+    @SerializedName("modid")
+    public String modId;
+
+    public String version = "";
+
+    public ModMetadata()
+    {
+    }
+}