improved fastjson 1.x compatible, support SerializerFeature.WriteEnumUsingName, fix issue #859

Author: wenshao

core/src/test/java/com/alibaba/fastjson2/issues/Issue859.java

@@ -0,0 +1,37 @@
+package com.alibaba.fastjson2.issues;
+
+import com.alibaba.fastjson2.JSON;
+import com.alibaba.fastjson2.JSONWriter;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class Issue859 {
+    @Test
+    public void test() {
+        PayoutBill payoutBill = PayoutBill.builder().currency(Currency.CNY).build();
+        String str = JSON.toJSONString(payoutBill, JSONWriter.Feature.WriteEnumsUsingName);
+        assertEquals("{\"currency\":\"CNY\"}", str);
+    }
+
+    @Getter
+    @AllArgsConstructor
+    public enum Currency {
+        CNY("人民币"),
+        USD("美元"),
+        EUR("欧元"),
+        GBP("英镑"),
+        HKD("港币");
+
+        private final String desc;
+    }
+
+    @Builder
+    @Getter
+    public static class PayoutBill{
+        private Currency currency;
+    }
+}

fastjson1-compatible/src/main/java/com/alibaba/fastjson/JSON.java

@@ -693,6 +693,10 @@ public static JSONWriter.Context createWriteContext(SerializeConfig config, int
             context.config(JSONWriter.Feature.WriteEnumUsingToString);
         }
 
+        if ((featuresValue & SerializerFeature.WriteEnumUsingName.mask) != 0) {
+            context.config(JSONWriter.Feature.WriteEnumsUsingName);
+        }
+
         if ((featuresValue & SerializerFeature.NotWriteRootClassName.mask) != 0) {
             context.config(JSONWriter.Feature.NotWriteRootClassName);
         }

fastjson1-compatible/src/test/java/com/alibaba/fastjson/issues_compatible/Issue859.java

@@ -0,0 +1,37 @@
+package com.alibaba.fastjson.issues_compatible;
+
+import com.alibaba.fastjson.JSON;
+import com.alibaba.fastjson.serializer.SerializerFeature;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Getter;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class Issue859 {
+    @Test
+    public void test() {
+        PayoutBill payoutBill = PayoutBill.builder().currency(Currency.CNY).build();
+        String str = JSON.toJSONString(payoutBill, SerializerFeature.WriteEnumUsingName);
+        assertEquals("{\"currency\":\"CNY\"}", str);
+    }
+
+    @Getter
+    @AllArgsConstructor
+    public enum Currency {
+        CNY("人民币"),
+        USD("美元"),
+        EUR("欧元"),
+        GBP("英镑"),
+        HKD("港币");
+
+        private final String desc;
+    }
+
+    @Builder
+    @Getter
+    public static class PayoutBill{
+        private Currency currency;
+    }
+}