fix: fix resource isolate

Author: MC-XiaoHei

java21/src/main/java/org/leavesmc/leavesclip/Leavesclip.java

@@ -59,21 +59,21 @@ public static void main(final String[] args) {
             final URL[] classpathUrls = Arrays.copyOf(setupClasspathUrls, setupClasspathUrls.length + MixinJarResolver.jarUrls.length);
             System.arraycopy(MixinJarResolver.jarUrls, 0, classpathUrls, setupClasspathUrls.length, MixinJarResolver.jarUrls.length);
 
-            final ClassLoader parentClassLoader = Leavesclip.class.getClassLoader(); // remove .getParent(), hope no side-effect
+            final ClassLoader parentClassLoader = Leavesclip.class.getClassLoader();
             MixinServiceKnot.classLoader = Leavesclip.class.getClassLoader();
 
             MixinBootstrap.init();
             MixinEnvironment.getDefaultEnvironment().setSide(MixinEnvironment.Side.SERVER);
 
             classLoader = new MixinURLClassLoader(classpathUrls, parentClassLoader);
             ConditionChecker.setClassLoader(classLoader);
-            MixinServiceKnot.classLoader = classLoader;
             Mixins.addConfiguration("mixin-extras.init.mixins.json");
+            MixinServiceKnot.classLoader = classLoader;
             MixinJarResolver.mixinConfigs.forEach(Mixins::addConfiguration);
             decorateMixinConfigWithPluginId();
             AccessWidenerManager.initAccessWidener(classLoader);
         } else {
-            classLoader = new URLClassLoader(setupClasspathUrls);
+            classLoader = new URLClassLoader(setupClasspathUrls, Leavesclip.class.getClassLoader().getParent());
         }
 
         final String mainClassName = findMainClass();

java21/src/main/java/org/leavesmc/leavesclip/mixin/MixinURLClassLoader.java

@@ -1,12 +1,14 @@
 package org.leavesmc.leavesclip.mixin;
 
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 import org.spongepowered.asm.mixin.MixinEnvironment;
 import org.spongepowered.asm.mixin.transformer.IMixinTransformer;
 
 import java.io.InputStream;
 import java.net.URL;
 import java.net.URLClassLoader;
+import java.util.Objects;
 
 public class MixinURLClassLoader extends URLClassLoader {
     private final IMixinTransformer transformer;
@@ -20,6 +22,16 @@ public MixinURLClassLoader(URL[] urls, ClassLoader parent) {
         this.transformer = (IMixinTransformer) active;
     }
 
+    @Override
+    public @Nullable URL getResource(String name) {
+        Objects.requireNonNull(name);
+        if (name.endsWith(".class")) {
+            return super.getResource(name);
+        } else {
+            return findResource(name);
+        }
+    }
+
     @Override
     protected Class<?> findClass(@NotNull String name) throws ClassNotFoundException {
         String path = name.replace('.', '/') + ".class";