fix(java): support copy of non-serializable JDK classes such as java.lang.Package

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;
@@ -140,6 +141,7 @@ 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

@@ -116,7 +116,6 @@
 import org.apache.fory.reflect.ReflectionUtils;
 import org.apache.fory.serializer.ArraySerializers;
 import org.apache.fory.serializer.BufferSerializers;
-import org.apache.fory.serializer.CodegenSerializer.LazyInitBeanSerializer;
 import org.apache.fory.serializer.CompatibleSerializer;
 import org.apache.fory.serializer.CopyOnlyObjectSerializer;
 import org.apache.fory.serializer.EnumSerializer;
@@ -127,6 +126,8 @@
 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.CodegenSerializer.LazyInitBeanSerializer;
 import org.apache.fory.serializer.NoneSerializer;
 import org.apache.fory.serializer.ObjectSerializer;
 import org.apache.fory.serializer.OptionalSerializers;
@@ -1498,9 +1499,10 @@ 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));
+        if (cls.getName().startsWith("java") && !Serializable.class.isAssignableFrom(cls)){
+            // Route to a serializer that still refuses binary serialization (write/read throw) but
+            // supports field copy via AbstractObjectSerializer
+            return NonSerializableSerializer.class;
         }
       }
       if (ScalaTypes.SCALA_AVAILABLE && ReflectionUtils.isScalaSingletonObject(cls)) {

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

@@ -0,0 +1,52 @@
+/*
+ * 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.context.ReadContext;
+import org.apache.fory.context.WriteContext;
+import org.apache.fory.resolver.TypeResolver;
+
+/**
+ * Serializer for non-Serializable JDK classes. Binary serialization is unsupported —
+ * {@link #write}/{@link #read} throw {@link UnsupportedOperationException} — while copy
+ * reuses {@link AbstractObjectSerializer}'s field-copy implementation.
+ *
+ * <p>Distinct from {@link CopyOnlyObjectSerializer}, which blocks serialization for
+ * registration-security reasons (remediable by registering the class). Here serialization
+ * is intrinsically unsupported and not remediable by registration, so the failure semantics
+ * differ deliberately.
+ */
+public final class NonSerializableSerializer<T> extends AbstractObjectSerializer<T> {
+  public NonSerializableSerializer(TypeResolver typeResolver, Class<T> type) {
+      super(typeResolver, type);
+  }
+
+  @Override
+  public void write(WriteContext writeContext, T value) {
+      throw new UnsupportedOperationException(
+              String.format("Class %s doesn't support serialization.", type.getName()));
+  }
+
+  @Override
+  public T read(ReadContext readContext) {
+      throw new UnsupportedOperationException(
+              String.format("Class %s doesn't support serialization.", type.getName()));
+  }
+}

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;
@@ -454,4 +456,36 @@ public void testComplexCollectionCopy() {
       assertEquals(fory.copy(collectionFields).toCanEqual(), collectionFields.toCanEqual());
     }
   }
+
+  @Test
+  public void testCopyNonSerializableJdkClass(){
+
+    Fory fory = Fory.builder()
+            .withLanguage(Language.JAVA)
+            .requireClassRegistration(false)
+            .build();
+    Package pkg = String.class.getPackage();
+    Package copy = fory.copy(pkg);
+    Assert.assertNotNull(copy);
+    Assert.assertEquals(copy.getName(), pkg.getName());
+  }
+
+
+  @Test
+  public void testSerializeNonSerializableJdkClassStillThrows() {
+      // Serializing anon-serializable JDK class must still throw, just deferred to write time.
+
+      Fory fory = Fory.builder()
+              .withLanguage(Language.JAVA)
+              .requireClassRegistration(false)
+              .build();
+      try {
+          fory.serialize(String.class.getPackage());
+          Assert.fail("Expected serialization of java.lang.Package to fail");
+      } catch (SerializationException e) {
+          Assert.assertTrue(e.getCause() instanceof UnsupportedOperationException);
+          Assert.assertTrue(e.getMessage().contains("doesn't support serialization"));
+      }
+  }
+
 }