fix serialize field priority, for issue #1727

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

@@ -402,11 +402,17 @@ public int compareTo(Object o) {
             }
         }
 
-        if (thisMember instanceof Field && otherMember instanceof Method) {
+        if (thisMember instanceof Field
+                && otherMember instanceof Method
+                && ((Field) thisMember).getType() == ((Method) otherMember).getReturnType()
+        ) {
             return -1;
         }
 
-        if (thisMember instanceof Method && otherMember instanceof Field) {
+        if (thisMember instanceof Method
+                && otherMember instanceof Field
+                && ((Method) thisMember).getReturnType() == ((Field) otherMember).getType()
+        ) {
             return 1;
         }
 
@@ -454,6 +460,22 @@ public int compareTo(Object o) {
             }
         }
 
+        if (thisFieldClass.isPrimitive() && !otherFieldClass.isPrimitive()) {
+            return -1;
+        }
+
+        if (!thisFieldClass.isPrimitive() && otherFieldClass.isPrimitive()) {
+            return 1;
+        }
+
+        if (thisFieldClass.getName().startsWith("java.") && !otherFieldClass.getName().startsWith("java.")) {
+            return -1;
+        }
+
+        if (!thisFieldClass.getName().startsWith("java.") && otherFieldClass.getName().startsWith("java.")) {
+            return 1;
+        }
+
         return nameCompare;
     }
 

core/src/test/java/com/alibaba/fastjson2/issues_1700/Issue1727.java

@@ -0,0 +1,55 @@
+package com.alibaba.fastjson2.issues_1700;
+
+import com.alibaba.fastjson2.JSON;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class Issue1727 {
+    @Test
+    public void test() {
+        final Bean bean = new Bean();
+        bean.color = Color.BLUE;
+
+        assertEquals("{\"color\":5}", JSON.toJSONString(bean));
+    }
+
+    public enum Color {
+        RED(1),
+        YELLOW(3),
+        BLUE(5);
+
+        final Integer value;
+
+        Color(Integer value) {
+            this.value = value;
+        }
+    }
+
+    @Getter
+    public static class Bean {
+        public Color color;
+
+        public Integer getColor() {
+            return color.value;
+        }
+    }
+
+    @Test
+    public void test1() {
+        final Bean1 bean = new Bean1();
+        bean.color = Color.BLUE;
+
+        assertEquals("{\"color\":5}", JSON.toJSONString(bean));
+    }
+
+    @Getter
+    public static class Bean1 {
+        public Color color;
+
+        public int getColor() {
+            return color.value;
+        }
+    }
+}