chore(java): move ClassDef to meta package (#1515)

## What does this PR do?

This PR moved ClassDef from `type` to `meta` package for bettern manage
meta related classes

## Related issues

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## Does this PR introduce any user-facing change?

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- [ ] Does this PR introduce any public API change?
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## Benchmark

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java/fury-core/src/main/java/org/apache/fury/builder/CodecUtils.java

@@ -24,10 +24,10 @@
 import org.apache.fury.Fury;
 import org.apache.fury.codegen.CodeGenerator;
 import org.apache.fury.codegen.CompileUnit;
+import org.apache.fury.meta.ClassDef;
 import org.apache.fury.resolver.ClassResolver;
 import org.apache.fury.resolver.FieldResolver;
 import org.apache.fury.serializer.Serializer;
-import org.apache.fury.type.ClassDef;
 import org.apache.fury.util.Preconditions;
 
 /** Codec util to create and load jit serializer class. */

java/fury-core/src/main/java/org/apache/fury/builder/Generated.java

@@ -25,6 +25,7 @@
 import java.util.Objects;
 import org.apache.fury.Fury;
 import org.apache.fury.memory.MemoryBuffer;
+import org.apache.fury.meta.ClassDef;
 import org.apache.fury.serializer.CompatibleSerializerBase;
 import org.apache.fury.serializer.Serializer;
 import org.apache.fury.util.Preconditions;
@@ -99,7 +100,7 @@ public GeneratedObjectSerializer(Fury fury, Class<?> cls) {
     }
   }
 
-  /** Base class for all serializers with meta shared by {@link org.apache.fury.type.ClassDef}. */
+  /** Base class for all serializers with meta shared by {@link ClassDef}. */
   abstract class GeneratedMetaSharedSerializer extends GeneratedSerializer implements Generated {
     public static final String SERIALIZER_FIELD_NAME = "serializer";
 

java/fury-core/src/main/java/org/apache/fury/builder/MetaSharedCodecBuilder.java

@@ -32,12 +32,12 @@
 import org.apache.fury.config.CompatibleMode;
 import org.apache.fury.config.FuryBuilder;
 import org.apache.fury.memory.MemoryBuffer;
+import org.apache.fury.meta.ClassDef;
 import org.apache.fury.serializer.CodegenSerializer;
 import org.apache.fury.serializer.MetaSharedSerializer;
 import org.apache.fury.serializer.ObjectSerializer;
 import org.apache.fury.serializer.Serializer;
 import org.apache.fury.serializer.Serializers;
-import org.apache.fury.type.ClassDef;
 import org.apache.fury.type.Descriptor;
 import org.apache.fury.type.DescriptorGrouper;
 import org.apache.fury.util.Preconditions;

java/fury-core/src/main/java/org/apache/fury/type/ClassDef.java → java/fury-core/src/main/java/org/apache/fury/meta/ClassDef.java

@@ -17,7 +17,7 @@
  * under the License.
  */
 
-package org.apache.fury.type;
+package org.apache.fury.meta;
 
 import static org.apache.fury.type.TypeUtils.COLLECTION_TYPE;
 import static org.apache.fury.type.TypeUtils.MAP_TYPE;
@@ -48,6 +48,10 @@
 import org.apache.fury.memory.MemoryUtils;
 import org.apache.fury.resolver.ClassResolver;
 import org.apache.fury.serializer.CompatibleSerializer;
+import org.apache.fury.type.Descriptor;
+import org.apache.fury.type.DescriptorGrouper;
+import org.apache.fury.type.FinalObjectTypeStub;
+import org.apache.fury.type.GenericType;
 import org.apache.fury.util.MurmurHash3;
 import org.apache.fury.util.Platform;
 import org.apache.fury.util.Preconditions;
@@ -634,7 +638,7 @@ public int hashCode() {
   static FieldType buildFieldType(ClassResolver classResolver, Field field) {
     Preconditions.checkNotNull(field);
     Class<?> rawType = field.getType();
-    boolean isFinal = GenericType.defaultFinalPredicate.test(rawType);
+    boolean isFinal = GenericType.isFinalByDefault(rawType);
     if (Collection.class.isAssignableFrom(rawType)) {
       GenericType genericType = GenericType.build(field.getGenericType());
       return new CollectionFieldType(
@@ -672,15 +676,15 @@ static FieldType buildFieldType(ClassResolver classResolver, Field field) {
   private static FieldType buildFieldType(ClassResolver classResolver, GenericType genericType) {
     Preconditions.checkNotNull(genericType);
     boolean isFinal = genericType.isMonomorphic();
-    if (COLLECTION_TYPE.isSupertypeOf(genericType.typeToken)) {
+    if (COLLECTION_TYPE.isSupertypeOf(genericType.getTypeToken())) {
       return new CollectionFieldType(
           isFinal,
           buildFieldType(
               classResolver,
               genericType.getTypeParameter0() == null
                   ? GenericType.build(Object.class)
                   : genericType.getTypeParameter0()));
-    } else if (MAP_TYPE.isSupertypeOf(genericType.typeToken)) {
+    } else if (MAP_TYPE.isSupertypeOf(genericType.getTypeToken())) {
       return new MapFieldType(
           isFinal,
           buildFieldType(
@@ -694,7 +698,7 @@ private static FieldType buildFieldType(ClassResolver classResolver, GenericType
                   ? GenericType.build(Object.class)
                   : genericType.getTypeParameter1()));
     } else {
-      Short classId = classResolver.getRegisteredClassId(genericType.cls);
+      Short classId = classResolver.getRegisteredClassId(genericType.getCls());
       if (classId != null && classId != ClassResolver.NO_CLASS_ID) {
         return new RegisteredFieldType(isFinal, classId);
       } else {

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

@@ -97,6 +97,7 @@
 import org.apache.fury.logging.Logger;
 import org.apache.fury.logging.LoggerFactory;
 import org.apache.fury.memory.MemoryBuffer;
+import org.apache.fury.meta.ClassDef;
 import org.apache.fury.serializer.ArraySerializers;
 import org.apache.fury.serializer.BufferSerializers;
 import org.apache.fury.serializer.CodegenSerializer.LazyInitBeanSerializer;
@@ -133,7 +134,6 @@
 import org.apache.fury.serializer.scala.SingletonMapSerializer;
 import org.apache.fury.serializer.scala.SingletonObjectSerializer;
 import org.apache.fury.serializer.shim.ShimDispatcher;
-import org.apache.fury.type.ClassDef;
 import org.apache.fury.type.Descriptor;
 import org.apache.fury.type.GenericType;
 import org.apache.fury.type.ScalaTypes;

java/fury-core/src/main/java/org/apache/fury/resolver/MetaContext.java

@@ -23,7 +23,7 @@
 import java.util.List;
 import org.apache.fury.collection.IdentityObjectIntMap;
 import org.apache.fury.memory.MemoryBuffer;
-import org.apache.fury.type.ClassDef;
+import org.apache.fury.meta.ClassDef;
 
 /**
  * Context for sharing class meta across multiple serialization. Class name, field name and field

java/fury-core/src/main/java/org/apache/fury/serializer/MetaSharedSerializer.java

@@ -36,10 +36,10 @@
 import org.apache.fury.config.CompatibleMode;
 import org.apache.fury.config.FuryBuilder;
 import org.apache.fury.memory.MemoryBuffer;
+import org.apache.fury.meta.ClassDef;
 import org.apache.fury.resolver.ClassInfoHolder;
 import org.apache.fury.resolver.ClassResolver;
 import org.apache.fury.resolver.RefResolver;
-import org.apache.fury.type.ClassDef;
 import org.apache.fury.type.Descriptor;
 import org.apache.fury.type.DescriptorGrouper;
 import org.apache.fury.type.Generics;

java/fury-core/src/main/java/org/apache/fury/serializer/UnexistedClassSerializers.java

@@ -32,12 +32,12 @@
 import org.apache.fury.config.CompatibleMode;
 import org.apache.fury.config.Config;
 import org.apache.fury.memory.MemoryBuffer;
+import org.apache.fury.meta.ClassDef;
 import org.apache.fury.resolver.ClassInfo;
 import org.apache.fury.resolver.ClassInfoHolder;
 import org.apache.fury.resolver.ClassResolver;
 import org.apache.fury.resolver.MetaContext;
 import org.apache.fury.resolver.RefResolver;
-import org.apache.fury.type.ClassDef;
 import org.apache.fury.type.Descriptor;
 import org.apache.fury.type.DescriptorGrouper;
 import org.apache.fury.type.Generics;

java/fury-core/src/main/java/org/apache/fury/type/GenericType.java

@@ -36,9 +36,8 @@
 
 /** GenericType for building java generics as a tree and binding with fury serializers. */
 // TODO(chaokunyang) refine generics which can be inspired by spring ResolvableType.
-@SuppressWarnings("UnstableApiUsage")
 public class GenericType {
-  static final Predicate<Type> defaultFinalPredicate =
+  private static final Predicate<Type> defaultFinalPredicate =
       type -> {
         if (type.getClass() == Class.class) {
           return ReflectionUtils.isMonomorphic(((Class<?>) type));
@@ -215,4 +214,8 @@ public boolean hasGenericParameters() {
   public String toString() {
     return "GenericType{" + typeToken.toString() + '}';
   }
+
+  public static boolean isFinalByDefault(Class<?> cls) {
+    return defaultFinalPredicate.test(cls);
+  }
 }

java/fury-core/src/test/java/org/apache/fury/type/ClassDefTest.java

@@ -32,6 +32,7 @@
 import org.apache.fury.Fury;
 import org.apache.fury.FuryTestBase;
 import org.apache.fury.memory.MemoryBuffer;
+import org.apache.fury.meta.ClassDef;
 import org.apache.fury.util.ReflectionUtils;
 import org.testng.annotations.Test;