极验异常时，处理空指针问题

src/main/java/cn/quantgroup/xyqb/service/captcha/GeetestLib.java

@@ -7,6 +7,7 @@ import com.alibaba.fastjson.JSONException;
 import com.alibaba.fastjson.JSONObject;
 
 import lombok.extern.slf4j.Slf4j;
+import org.apache.commons.lang3.StringUtils;
 import org.apache.http.HttpStatus;
 
 import java.io.IOException;
@@ -297,17 +298,21 @@ public class GeetestLib {
         }
         String return_seccode = "";
         try {
+            if (StringUtils.isNotEmpty(response)) {
+                return val;
+            }
             JSONObject return_map = JSONObject.parseObject(response);
             return_seccode = return_map.getString("seccode");
             gtlog("md5: " + Md5Util.build(return_seccode));
             if (return_seccode.equals(Md5Util.build(seccode))) {
-                gtlog("validateMethod: "+ return_map.getString("challenge_type"));
+                gtlog("validateMethod: " + return_map.getString("challenge_type"));
                 val.put("validataMethod", return_map.getString("challenge_type"));
                 val.put("bl", 1);
                 return val;
             } else {
                 return val;
             }
+
         } catch (JSONException e) {
             gtlog("json load error");
             return val;
@@ -348,7 +353,7 @@ public class GeetestLib {
     protected boolean checkResultByPrivate(String challenge, String validate) {
         gtlog("privateKey: " + privateKey);
         String encodeStr = Md5Util.build(privateKey + "geetest" + challenge);
-        gtlog("encodeStr: "+ encodeStr);
+        gtlog("encodeStr: " + encodeStr);
         gtlog("valdate: " + validate);
         return validate.equals(encodeStr);
     }