diff --git a/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/manager/EnterpriseWeChatManager.java b/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/manager/EnterpriseWeChatManager.java
index 510d73b9f78dbaa95093608955cfaee25ab43537..9bcad56c24876939a116710a4f936952e6f41002 100644
--- a/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/manager/EnterpriseWeChatManager.java
+++ b/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/manager/EnterpriseWeChatManager.java
@@ -32,7 +32,7 @@ import java.util.Map;
  * Enterprise WeChat Manager
  */
 public class EnterpriseWeChatManager {
-    private static final Logger logger = LoggerFactory.getLogger(MsgManager.class);
+    private static final Logger logger = LoggerFactory.getLogger(EnterpriseWeChatManager.class);
     /**
      * Enterprise We Chat send
      * @param alert the alert
diff --git a/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/runner/AlertSender.java b/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/runner/AlertSender.java
index 718ef5094803a53f44c850ea816cb1b5739df063..d54c2327be2ab97cf6f58699d8e18b3dbaf042c7 100644
--- a/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/runner/AlertSender.java
+++ b/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/runner/AlertSender.java
@@ -65,7 +65,7 @@ public class AlertSender{
             users = alertDao.listUserByAlertgroupId(alert.getAlertGroupId());
 
             // receiving group list
-            List<String> receviersList = new ArrayList<String>();
+            List<String> receviersList = new ArrayList<>();
             for(User user:users){
                 receviersList.add(user.getEmail());
             }
@@ -77,7 +77,7 @@ public class AlertSender{
             }
 
             // copy list
-            List<String> receviersCcList = new ArrayList<String>();
+            List<String> receviersCcList = new ArrayList<>();
 
 
             // Custom Copier
diff --git a/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/template/AlertTemplate.java b/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/template/AlertTemplate.java
index cc74ff71ee09f33ba969131b40643f9425537e58..81b5e65f274f5c81b264a37ea9612e6757df0b18 100644
--- a/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/template/AlertTemplate.java
+++ b/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/template/AlertTemplate.java
@@ -34,6 +34,9 @@ public interface AlertTemplate {
 
     /**
      * default showAll is true
+     * @param content alert message content
+     * @param showType show type
+     * @return a message from a specified alert template
      */
     default String getMessageFromTemplate(String content,ShowType showType){
         return getMessageFromTemplate(content,showType,true);
diff --git a/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/EnterpriseWeChatUtils.java b/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/EnterpriseWeChatUtils.java
index a4c372058110b3ca00c18578ee8fcfbb19bb87f1..ff8822421a7f1f76b47d4023ffcfc6f4d4a4c776 100644
--- a/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/EnterpriseWeChatUtils.java
+++ b/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/EnterpriseWeChatUtils.java
@@ -201,22 +201,22 @@ public class EnterpriseWeChatUtils {
     public static String markdownTable(String title,String content){
         List<LinkedHashMap> mapItemsList = JSONUtils.toList(content, LinkedHashMap.class);
         StringBuilder contents = new StringBuilder(200);
-        for (LinkedHashMap mapItems : mapItemsList){
 
-            Set<Map.Entry<String, String>> entries = mapItems.entrySet();
+        if (null != mapItemsList) {
+            for (LinkedHashMap mapItems : mapItemsList){
+                Set<Map.Entry<String, String>> entries = mapItems.entrySet();
+                Iterator<Map.Entry<String, String>> iterator = entries.iterator();
+                StringBuilder t = new StringBuilder(String.format("`%s`%s",title,Constants.MARKDOWN_ENTER));
 
-            Iterator<Map.Entry<String, String>> iterator = entries.iterator();
+                while (iterator.hasNext()){
 
-            StringBuilder t = new StringBuilder(String.format("`%s`%s",title,Constants.MARKDOWN_ENTER));
-            while (iterator.hasNext()){
-
-                Map.Entry<String, String> entry = iterator.next();
-                t.append(Constants.MARKDOWN_QUOTE);
-                t.append(entry.getKey()).append(":").append(entry.getValue());
-                t.append(Constants.MARKDOWN_ENTER);
+                    Map.Entry<String, String> entry = iterator.next();
+                    t.append(Constants.MARKDOWN_QUOTE);
+                    t.append(entry.getKey()).append(":").append(entry.getValue());
+                    t.append(Constants.MARKDOWN_ENTER);
+                }
+                contents.append(t);
             }
-
-            contents.append(t);
         }
         return contents.toString();
     }
diff --git a/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/MailUtils.java b/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/MailUtils.java
index e911817354025321b5fc6af980c2f55c31a3745e..7ebe6a786338b27cf82014a7c7719290028109c7 100644
--- a/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/MailUtils.java
+++ b/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/MailUtils.java
@@ -96,7 +96,7 @@ public class MailUtils {
             return retMap;
         }
 
-        receivers.removeIf((from) -> (StringUtils.isEmpty(from)));
+        receivers.removeIf(StringUtils::isEmpty);
         
         if (showType == ShowType.TABLE || showType == ShowType.TEXT){
             // send email
@@ -185,7 +185,7 @@ public class MailUtils {
 
     /**
      * get MimeMessage
-     * @param receivers
+     * @param receivers receivers
      * @return the MimeMessage
      * @throws MessagingException
      */
@@ -229,8 +229,7 @@ public class MailUtils {
             }
         };
 
-        Session session = Session.getInstance(props, auth);
-        return session;
+        return Session.getInstance(props, auth);
     }
 
     /**
diff --git a/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/PropertyUtils.java b/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/PropertyUtils.java
index 4367fbb4a8206e7c4e3286465d23dfae3824215e..c2f479d101f9e013534e79cbb7998b3f37832e67 100644
--- a/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/PropertyUtils.java
+++ b/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/PropertyUtils.java
@@ -205,8 +205,7 @@ public class PropertyUtils {
             return null;
         }
         try {
-            String[] propertyArray = value.split(splitStr);
-            return propertyArray;
+            return value.split(splitStr);
         } catch (PatternSyntaxException e) {
             logger.info(e.getMessage(),e);
         }
diff --git a/dolphinscheduler-api/src/main/java/org/apache/dolphinscheduler/api/utils/FileUtils.java b/dolphinscheduler-api/src/main/java/org/apache/dolphinscheduler/api/utils/FileUtils.java
index f88d26164bb0b9e42dd83a0bfb6ddc0106c3e379..355f6c954eb51b3015ff7a34cd424600e171baa2 100644
--- a/dolphinscheduler-api/src/main/java/org/apache/dolphinscheduler/api/utils/FileUtils.java
+++ b/dolphinscheduler-api/src/main/java/org/apache/dolphinscheduler/api/utils/FileUtils.java
@@ -57,7 +57,7 @@ public class FileUtils {
 
             Files.copy(file.getInputStream(), Paths.get(destFilename));
         } catch (IOException e) {
-            logger.error(String.format("failed to copy file , {} is empty file", file.getOriginalFilename()), e);
+            logger.error("failed to copy file , {} is empty file", file.getOriginalFilename(), e);
         }
     }