fix(java): copy non-serializable JDK objects by reference

java/fory-core/src/main/java/org/apache/fory/platform/GraalvmSupport.java

@@ -39,6 +39,7 @@
 import org.apache.fory.serializer.JavaSerializer;
 import org.apache.fory.serializer.JdkProxySerializer;
 import org.apache.fory.serializer.LambdaSerializer;
+import org.apache.fory.serializer.NonSerializableSerializer;
 import org.apache.fory.serializer.ObjectSerializer;
 import org.apache.fory.serializer.ObjectStreamSerializer;
 import org.apache.fory.serializer.PrimitiveArraySerializers;
@@ -137,6 +138,7 @@ public class GraalvmSupport {
     registerDefaultSerializerClass(ObjectStreamSerializer.class);
     registerDefaultSerializerClass(JavaSerializer.class);
     registerDefaultSerializerClass(ObjectSerializer.class);
+    registerDefaultSerializerClass(NonSerializableSerializer.class);
   }
 
   /** Returns true if current process is running in graalvm native image build stage. */

java/fory-core/src/main/java/org/apache/fory/resolver/ClassResolver.java

@@ -124,6 +124,7 @@
 import org.apache.fory.serializer.JdkProxySerializer;
 import org.apache.fory.serializer.LambdaSerializer;
 import org.apache.fory.serializer.LocaleSerializer;
+import org.apache.fory.serializer.NonSerializableSerializer;
 import org.apache.fory.serializer.NoneSerializer;
 import org.apache.fory.serializer.ObjectSerializer;
 import org.apache.fory.serializer.OptionalSerializers;
@@ -1502,8 +1503,7 @@ public Class<? extends Serializer> getSerializerClass(Class<?> cls, boolean code
       }
       if (config.checkJdkClassSerializable()) {
         if (cls.getName().startsWith("java") && !(Serializable.class.isAssignableFrom(cls))) {
-          throw new UnsupportedOperationException(
-              String.format("Class %s doesn't support serialization.", cls));
+          return NonSerializableSerializer.class;
         }
       }
       if (ScalaTypes.SCALA_AVAILABLE && ReflectionUtils.isScalaSingletonObject(cls)) {

java/fory-core/src/main/java/org/apache/fory/serializer/NonSerializableSerializer.java

@@ -0,0 +1,50 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.fory.serializer;
+
+import org.apache.fory.config.Config;
+import org.apache.fory.context.ReadContext;
+import org.apache.fory.context.WriteContext;
+
+/**
+ * Serializer for non-serializable JDK types that are retained by reference during copy.
+ *
+ * <p>These objects can contain JVM-managed state, so copying their fields is unsupported.
+ */
+public final class NonSerializableSerializer<T> extends Serializer<T> {
+  public NonSerializableSerializer(Config config, Class<T> type) {
+    super(config, type, true);
+  }
+
+  @Override
+  public void write(WriteContext writeContext, T value) {
+    throw unsupportedOperation();
+  }
+
+  @Override
+  public T read(ReadContext readContext) {
+    throw unsupportedOperation();
+  }
+
+  private UnsupportedOperationException unsupportedOperation() {
+    return new UnsupportedOperationException(
+        String.format("Class %s doesn't support serialization.", type));
+  }
+}

java/fory-core/src/test/java/org/apache/fory/ForyCopyTest.java

@@ -79,10 +79,12 @@
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.regex.Pattern;
 import org.apache.fory.collection.LazyMap;
+import org.apache.fory.config.Language;
 import org.apache.fory.context.CopyContext;
 import org.apache.fory.context.ReadContext;
 import org.apache.fory.context.WriteContext;
 import org.apache.fory.exception.ForyException;
+import org.apache.fory.exception.SerializationException;
 import org.apache.fory.resolver.TypeResolver;
 import org.apache.fory.serializer.EnumSerializerTest;
 import org.apache.fory.serializer.EnumSerializerTest.EnumFoo;
@@ -210,6 +212,35 @@ public void testCopyOnlySerializerStillRejectsSerialize() {
     Assert.assertThrows(ForyException.class, () -> fory.serialize(beanA));
   }
 
+  @Test
+  public void testCopyNonSerializableJdkObject() {
+    Fory fory =
+        builder()
+            .withLanguage(Language.JAVA)
+            .withRefTracking(true)
+            .withRefCopy(true)
+            .requireClassRegistration(false)
+            .build();
+    Package packageValue = String.class.getPackage();
+
+    Assert.assertSame(fory.copy(packageValue), packageValue);
+
+    Object[] values = new Object[] {packageValue};
+    Object[] copiedValues = fory.copy(values);
+    Assert.assertNotSame(copiedValues, values);
+    Assert.assertSame(copiedValues[0], packageValue);
+  }
+
+  @Test
+  public void testSerializeNonSerializableJdkObjectStillFails() {
+    Fory fory = builder().withLanguage(Language.JAVA).requireClassRegistration(false).build();
+    Package packageValue = String.class.getPackage();
+
+    SerializationException exception =
+        Assert.expectThrows(SerializationException.class, () -> fory.serialize(packageValue));
+    Assert.assertTrue(exception.getCause() instanceof UnsupportedOperationException);
+  }
+
   @Test
   public void testCopyFailureDoesNotLeakCopyDepth() {
     Fory fory =