From a3ce9a307cd38355e5827aa50b9125c032be6831 Mon Sep 17 00:00:00 2001
From: LiangliangSui <coolsui.coding@gmail.com>
Date: Mon, 1 Jul 2024 11:51:42 +0800
Subject: [PATCH] update

Signed-off-by: LiangliangSui <coolsui.coding@gmail.com>
---
 .../src/main/java/org/apache/fury/Fury.java   | 22 +++++++++++--------
 .../apache/fury/resolver/ClassResolver.java   |  4 ++++
 .../test/java/org/apache/fury/FuryTest.java   | 13 +++++++++++
 3 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/java/fury-core/src/main/java/org/apache/fury/Fury.java b/java/fury-core/src/main/java/org/apache/fury/Fury.java
index ccef2aaa3d..94e75e4a39 100644
--- a/java/fury-core/src/main/java/org/apache/fury/Fury.java
+++ b/java/fury-core/src/main/java/org/apache/fury/Fury.java
@@ -45,6 +45,7 @@
 import org.apache.fury.resolver.ClassInfoHolder;
 import org.apache.fury.resolver.ClassResolver;
 import org.apache.fury.resolver.MapRefResolver;
+import org.apache.fury.resolver.MetaContext;
 import org.apache.fury.resolver.MetaStringResolver;
 import org.apache.fury.resolver.NoRefResolver;
 import org.apache.fury.resolver.RefResolver;
@@ -310,12 +311,14 @@ private void write(MemoryBuffer buffer, Object obj) {
       buffer.writeInt32(-1); // preserve 4-byte for nativeObjects start offsets.
     }
     // reduce caller stack
-    if (!refResolver.writeRefOrNull(buffer, obj)) {
+    boolean isNull = refResolver.writeRefOrNull(buffer, obj);
+    if (!isNull) {
       ClassInfo classInfo = classResolver.getOrUpdateClassInfo(obj.getClass());
       classResolver.writeClass(buffer, classInfo);
       writeData(buffer, classInfo, obj);
     }
-    if (shareMeta) {
+    MetaContext metaContext = getSerializationContext().getMetaContext();
+    if (shareMeta && !isNull && !metaContext.writingClassDefs.isEmpty()) {
       buffer.putInt32(startOffset, buffer.writerIndex());
       classResolver.writeClassDefs(buffer);
     }
@@ -1031,14 +1034,15 @@ public void serializeJavaObject(MemoryBuffer buffer, Object obj) {
         if (!refResolver.writeRefOrNull(buffer, obj)) {
           ClassInfo classInfo = classResolver.getOrUpdateClassInfo(obj.getClass());
           writeData(buffer, classInfo, obj);
+          MetaContext metaContext = getSerializationContext().getMetaContext();
+          if (!metaContext.writingClassDefs.isEmpty()) {
+            buffer.putInt32(startOffset, buffer.writerIndex());
+            classResolver.writeClassDefs(buffer);
+          }
         }
-        buffer.putInt32(startOffset, buffer.writerIndex());
-        classResolver.writeClassDefs(buffer);
-      } else {
-        if (!refResolver.writeRefOrNull(buffer, obj)) {
-          ClassInfo classInfo = classResolver.getOrUpdateClassInfo(obj.getClass());
-          writeData(buffer, classInfo, obj);
-        }
+      } else if (!refResolver.writeRefOrNull(buffer, obj)) {
+        ClassInfo classInfo = classResolver.getOrUpdateClassInfo(obj.getClass());
+        writeData(buffer, classInfo, obj);
       }
     } catch (StackOverflowError t) {
       throw processStackOverflowError(t);
diff --git a/java/fury-core/src/main/java/org/apache/fury/resolver/ClassResolver.java b/java/fury-core/src/main/java/org/apache/fury/resolver/ClassResolver.java
index 58ea84aadb..ec16655918 100644
--- a/java/fury-core/src/main/java/org/apache/fury/resolver/ClassResolver.java
+++ b/java/fury-core/src/main/java/org/apache/fury/resolver/ClassResolver.java
@@ -1423,6 +1423,10 @@ public void writeClassDefs(MemoryBuffer buffer) {
   public void readClassDefs(MemoryBuffer buffer) {
     MetaContext metaContext = fury.getSerializationContext().getMetaContext();
     int classDefOffset = buffer.readInt32();
+    if (classDefOffset == -1) {
+      // -1 means no ClassDefs are available to read.
+      return;
+    }
     int readerIndex = buffer.readerIndex();
     buffer.readerIndex(classDefOffset);
     int numClassDefs = buffer.readVarUint32Small14();
diff --git a/java/fury-core/src/test/java/org/apache/fury/FuryTest.java b/java/fury-core/src/test/java/org/apache/fury/FuryTest.java
index 072ff9f6cc..0178128fd5 100644
--- a/java/fury-core/src/test/java/org/apache/fury/FuryTest.java
+++ b/java/fury-core/src/test/java/org/apache/fury/FuryTest.java
@@ -560,4 +560,17 @@ public void testPrintReadObjectsWhenFailed() {
       Assert.assertTrue(e.getMessage().contains("[a, b]"));
     }
   }
+
+  @Test
+  public void testNullObjSerAndDe() {
+    Fury fury =
+        Fury.builder()
+            .withRefTracking(true)
+            .requireClassRegistration(false)
+            .withMetaShare(true)
+            .build();
+    byte[] bytes = fury.serializeJavaObjectAndClass(null);
+    Object obj = fury.deserializeJavaObjectAndClass(bytes);
+    assertNull(obj);
+  }
 }