fix not root class name when specified in @jsontype, for issue #2662

core/src/main/java/com/alibaba/fastjson2/writer/ObjectWriterCreatorASM.java

@@ -739,7 +739,7 @@ private static void isWriteTypeInfo(
             int FEILD_FEATURE,
             Label notWriteType
     ) {
-        if ((objectFeatures & JSONWriter.Feature.WriteClassName.mask) == 0) {
+        if ((objectFeatures & JSONWriter.Feature.WriteClassName.mask) == 0 || (objectFeatures & NotWriteRootClassName.mask) != 0) {
             mw.visitVarInsn(Opcodes.ALOAD, OBJECT);
             mw.visitJumpInsn(Opcodes.IFNULL, notWriteType);
 

core/src/test/java/com/alibaba/fastjson2/issues_2600/Issue2662.java

@@ -0,0 +1,59 @@
+package com.alibaba.fastjson2.issues_2600;
+
+import com.alibaba.fastjson2.JSON;
+import com.alibaba.fastjson2.JSONWriter;
+import com.alibaba.fastjson2.annotation.JSONType;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class Issue2662 {
+    @Test
+    public void test() {
+        final WrapperClassA wrapperClassA = new WrapperClassA();
+        final PojoClassC pojoClassC = new PojoClassC();
+        pojoClassC.setInt1(1);
+        pojoClassC.setStr2("str");
+        wrapperClassA.setPojo(pojoClassC);
+        final String jsonStr = JSON.toJSONString(wrapperClassA);
+        assertEquals("{\"pojo\":{\"@type\":\"com.alibaba.fastjson2.issues_2600.Issue2662$PojoClassC\",\"int1\":1,\"str2\":\"str\"}}", jsonStr);
+    }
+
+    @JSONType(serializeFeatures = {JSONWriter.Feature.WriteClassName, JSONWriter.Feature.NotWriteRootClassName})
+    public static class WrapperClassA {
+        private AbsPojoClassB pojo;
+
+        public AbsPojoClassB getPojo() {
+            return pojo;
+        }
+
+        public void setPojo(AbsPojoClassB pojo) {
+            this.pojo = pojo;
+        }
+    }
+
+    public static class AbsPojoClassB {
+        private Integer int1;
+        private String str2;
+
+        public Integer getInt1() {
+            return int1;
+        }
+
+        public void setInt1(Integer int1) {
+            this.int1 = int1;
+        }
+
+        public String getStr2() {
+            return str2;
+        }
+
+        public void setStr2(String str2) {
+            this.str2 = str2;
+        }
+    }
+
+    public static class PojoClassC
+            extends AbsPojoClassB {
+    }
+}