fix(java): References within InvocationHandler, Issue #1364 - optimiz…

…ations from discussion

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

@@ -20,6 +20,7 @@
 package org.apache.fury.serializer;
 
 import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.Method;
 import java.lang.reflect.Proxy;
 import org.apache.fury.Fury;
 import org.apache.fury.memory.MemoryBuffer;
@@ -33,16 +34,15 @@
 public class JdkProxySerializer extends Serializer {
 
   // Make offset compatible with graalvm native image.
-  private static final long PROXY_HANDLER_FIELD_OFFSET;
-
-  static {
-    try {
-      // Make offset compatible with graalvm native image.
-      PROXY_HANDLER_FIELD_OFFSET = Platform.objectFieldOffset(Proxy.class.getDeclaredField("h"));
-    } catch (NoSuchFieldException e) {
-      throw new RuntimeException(e);
-    }
-  }
+  private static final long PROXY_HANDLER_FIELD_OFFSET =
+      Platform.objectFieldOffset(Proxy.class, InvocationHandler.class);
+  private static final InvocationHandler STUB_HANDLER =
+      new InvocationHandler() {
+        @Override
+        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
+          throw new IllegalStateException("Deserialization stub handler still active");
+        }
+      };
 
   public JdkProxySerializer(Fury fury, Class cls) {
     super(fury, cls);
@@ -63,8 +63,7 @@ public Object read(MemoryBuffer buffer) {
     final int refId = resolver.lastPreservedRefId();
     final Class<?>[] interfaces = (Class<?>[]) fury.readRef(buffer);
     Preconditions.checkNotNull(interfaces);
-    final Class<?> proxyClass = Proxy.getProxyClass(fury.getClassLoader(), interfaces);
-    Object proxy = Platform.newInstance(proxyClass);
+    Object proxy = Proxy.newProxyInstance(fury.getClassLoader(), interfaces, STUB_HANDLER);
     resolver.setReadObject(refId, proxy);
     InvocationHandler invocationHandler = (InvocationHandler) fury.readRef(buffer);
     Preconditions.checkNotNull(invocationHandler);

java/fury-core/src/main/java/org/apache/fury/util/Platform.java

@@ -143,6 +143,39 @@ public static long objectFieldOffset(Field f) {
     return UNSAFE.objectFieldOffset(f);
   }
 
+  /**
+   * Gets the offset of the only field in the class matching the required type
+   *
+   * @param clazz the class in which the field should be declared
+   * @param fieldType the required type of the field
+   * @return
+   * @throws IllegalStateException if there are multiple fields of the required type
+   * @throws IllegalArgumentException if there are no fields of the required type
+   */
+  public static long objectFieldOffset(Class<?> clazz, Class<?> fieldType) {
+    Field f = null;
+    for (Field fi : clazz.getDeclaredFields()) {
+      if (fieldType.equals(fi.getType())) {
+        if (f != null)
+          throw new IllegalStateException(
+              "Found multiple field s matching "
+                  + fieldType
+                  + " in "
+                  + clazz
+                  + ": "
+                  + f
+                  + " and "
+                  + fi);
+
+        f = fi;
+      }
+    }
+    if (f == null)
+      throw new IllegalArgumentException(
+          "Found no field matching " + fieldType.getName() + " in " + clazz + "!");
+    return objectFieldOffset(f);
+  }
+
   public static int getInt(Object object, long offset) {
     return UNSAFE.getInt(object, offset);
   }