Fix issue#3601

src/main/java/com/alibaba/fastjson/serializer/SerializeConfig.java

@@ -77,7 +77,7 @@ public class SerializeConfig {
             };
 
     private List<Module>                                    modules                = new ArrayList<Module>();
-    
+
 	public String getTypeKey() {
 		return typeKey;
 	}
@@ -852,12 +852,9 @@ private static Member getEnumValueField(Class clazz) {
         for (Field field : clazz.getFields()) {
             JSONField jsonField = field.getAnnotation(JSONField.class);
 
+            // Returns null if @JSONField is on the enumeration field
             if (jsonField != null) {
-                if (member != null) {
-                    return null;
-                }
-
-                member = field;
+                return null;
             }
         }
 

src/test/java/com/alibaba/fastjson/serializer/issues3601/TestEntity.java

@@ -0,0 +1,9 @@
+package com.alibaba.fastjson.serializer.issues3601;
+
+import lombok.Data;
+
+@Data
+public class TestEntity {
+    private TestEnum testEnum;
+    private String testName;
+}

src/test/java/com/alibaba/fastjson/serializer/issues3601/TestEnum.java

@@ -0,0 +1,32 @@
+package com.alibaba.fastjson.serializer.issues3601;
+
+import com.alibaba.fastjson.annotation.JSONField;
+
+public enum TestEnum {
+
+    @JSONField
+    test1("1"),
+//    @JSONField
+    test2("2");
+
+    private String title;
+
+    TestEnum(String title) {
+        this.title = title;
+    }
+
+//    @JSONField
+    public String getTitle() {
+        return title;
+    }
+
+    private Integer i = 100;
+
+    @JSONField
+    public Integer getI() {
+        return i;
+    }
+
+}
+
+

src/test/java/com/alibaba/fastjson/serializer/issues3601/TestIssue3601.java

@@ -0,0 +1,19 @@
+package com.alibaba.fastjson.serializer.issues3601;
+
+import com.alibaba.fastjson.JSON;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TestIssue3601 {
+
+    @Test
+    public void enumTest() {
+        TestEntity testEntity = new TestEntity();
+        testEntity.setTestName("ganyu");
+        testEntity.setTestEnum(TestEnum.test1);
+        String json = JSON.toJSONString(testEntity);
+        System.out.println(json);
+        Assert.assertEquals("{\"testEnum\":\"test1\",\"testName\":\"ganyu\"}", json);
+    }
+
+}