From 46a5d693a379df194765d327dfbf4bff3436eae7 Mon Sep 17 00:00:00 2001
From: Cooper <12110517@mail.sustech.edu.cn>
Date: Sun, 28 Jul 2024 22:13:06 +0800
Subject: [PATCH] fix JSONObject ClassCastException, for issue #2762

---
 .../main/java/com/alibaba/fastjson/JSONObject.java |  4 ++++
 .../com/alibaba/fastjson/v2issues/Issue2762.java   | 14 ++++++++++++++
 2 files changed, 18 insertions(+)
 create mode 100644 fastjson1-compatible/src/test/java/com/alibaba/fastjson/v2issues/Issue2762.java

diff --git a/fastjson1-compatible/src/main/java/com/alibaba/fastjson/JSONObject.java b/fastjson1-compatible/src/main/java/com/alibaba/fastjson/JSONObject.java
index b0f17e26f7..f749e85a36 100755
--- a/fastjson1-compatible/src/main/java/com/alibaba/fastjson/JSONObject.java
+++ b/fastjson1-compatible/src/main/java/com/alibaba/fastjson/JSONObject.java
@@ -127,6 +127,10 @@ public Object get(Object key) {
             val = map.get(key.toString());
         }
 
+        if (val instanceof com.alibaba.fastjson2.JSONObject) {
+            val = new com.alibaba.fastjson.JSONObject((com.alibaba.fastjson2.JSONObject) val);
+        }
+
         return val;
     }
 
diff --git a/fastjson1-compatible/src/test/java/com/alibaba/fastjson/v2issues/Issue2762.java b/fastjson1-compatible/src/test/java/com/alibaba/fastjson/v2issues/Issue2762.java
new file mode 100644
index 0000000000..22881213e6
--- /dev/null
+++ b/fastjson1-compatible/src/test/java/com/alibaba/fastjson/v2issues/Issue2762.java
@@ -0,0 +1,14 @@
+package com.alibaba.fastjson.v2issues;
+
+import com.alibaba.fastjson.JSONObject;
+import org.json.JSONException;
+import org.junit.jupiter.api.Test;
+
+public class Issue2762 {
+    @Test
+    public void test() throws JSONException {
+        String jsonString = "{\"this0\":{\"$ref\":\"1\"}}";
+        JSONObject jsonObject = JSONObject.parseObject(jsonString, JSONObject.class);
+        JSONObject innerObject1 = (JSONObject) jsonObject.get("this0");
+    }
+}