支持空类型（默认DEFAULT）

src/main/java/cn/quantgroup/xyqb/model/sms/SmsMerchant.java

 package cn.quantgroup.xyqb.model.sms;
 
 import lombok.extern.slf4j.Slf4j;
+import org.apache.commons.lang3.StringUtils;
 
 import java.util.Optional;
 
@@ -54,7 +55,9 @@ public enum SmsMerchant {
      * @return
      */
     public static SmsMerchant of(String name){
-        name = Optional.ofNullable(name).orElse("");
+        if(StringUtils.isBlank(name)){
+            return DEFAULT;
+        }
         SmsMerchant merchant = null;
         try{
             merchant = SmsMerchant.valueOf(name.toUpperCase());