流量统计，修复问题

util/json_util/json.go

@@ -0,0 +1,37 @@
+package json_util
+
+import (
+	"encoding/json"
+	"reflect"
+	"x-ui/util/reflect_util"
+)
+
+/*
+MarshalJSON 特殊处理 json.RawMessage
+
+当 json.RawMessage 不为 nil 且 len() 为 0 时，MarshalJSON 将会解析报错
+*/
+func MarshalJSON(i interface{}) ([]byte, error) {
+	m := map[string]interface{}{}
+	t := reflect.TypeOf(i).Elem()
+	v := reflect.ValueOf(i).Elem()
+	fields := reflect_util.GetFields(t)
+	for _, field := range fields {
+		key := field.Tag.Get("json")
+		if key == "" || key == "-" {
+			continue
+		}
+		fieldV := v.FieldByName(field.Name)
+		value := fieldV.Interface()
+		switch value.(type) {
+		case json.RawMessage:
+			value := value.(json.RawMessage)
+			if len(value) > 0 {
+				m[key] = value
+			}
+		default:
+			m[key] = value
+		}
+	}
+	return json.Marshal(m)
+}