diff --git a/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/FuncUtils.java b/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/FuncUtils.java
index e682fde2e7..186a983e05 100644
--- a/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/FuncUtils.java
+++ b/dolphinscheduler-alert/src/main/java/org/apache/dolphinscheduler/alert/utils/FuncUtils.java
@@ -16,9 +16,16 @@
  */
 package org.apache.dolphinscheduler.alert.utils;
 
+import org.apache.commons.lang.StringUtils;
+
 public class FuncUtils {
 
     static public String mkString(Iterable<String> list, String split) {
+
+        if (null == list || StringUtils.isEmpty(split)){
+            return null;
+        }
+
         StringBuilder sb = new StringBuilder();
         boolean first = true;
         for (String item : list) {
diff --git a/dolphinscheduler-alert/src/test/java/org/apache/dolphinscheduler/alert/utils/FuncUtilsTest.java b/dolphinscheduler-alert/src/test/java/org/apache/dolphinscheduler/alert/utils/FuncUtilsTest.java
new file mode 100644
index 0000000000..e2b25d961d
--- /dev/null
+++ b/dolphinscheduler-alert/src/test/java/org/apache/dolphinscheduler/alert/utils/FuncUtilsTest.java
@@ -0,0 +1,60 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.dolphinscheduler.alert.utils;
+
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Arrays;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+public class FuncUtilsTest {
+
+    private static final Logger logger = LoggerFactory.getLogger(FuncUtilsTest.class);
+
+    /**
+     * Test mkString
+     */
+    @Test
+    public void testMKString() {
+
+        //Define users list
+        Iterable<String> users = Arrays.asList("user1", "user2", "user3");
+        //Define split
+        String split = "|";
+
+        //Invoke mkString with correctParams
+        String result = FuncUtils.mkString(users, split);
+        logger.info(result);
+
+        //Expected result string
+        assertEquals(result, "user1|user2|user3");
+
+        //Null list expected return null
+        result = FuncUtils.mkString(null, split);
+        assertNull(result);
+
+        //Null split expected return null
+        result = FuncUtils.mkString(users, null);
+        assertNull(result);
+
+    }
+}
\ No newline at end of file
diff --git a/dolphinscheduler-alert/src/test/java/org/apache/dolphinscheduler/alert/utils/JSONUtilsTest.java b/dolphinscheduler-alert/src/test/java/org/apache/dolphinscheduler/alert/utils/JSONUtilsTest.java
new file mode 100644
index 0000000000..cb63a22d79
--- /dev/null
+++ b/dolphinscheduler-alert/src/test/java/org/apache/dolphinscheduler/alert/utils/JSONUtilsTest.java
@@ -0,0 +1,112 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.dolphinscheduler.alert.utils;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+public class JSONUtilsTest {
+
+    private static final Logger logger = LoggerFactory.getLogger(JSONUtilsTest.class);
+
+    public List<LinkedHashMap<String, Object>> list = new ArrayList<>();
+
+    public String expected = null;
+
+    @Before
+    public void setUp() throws Exception {
+
+        //Define expected json string
+        expected = "[{\"mysql service name\":\"mysql200\",\"mysql address\":\"192.168.xx.xx\",\"port\":\"3306\",\"no index of number\":\"80\",\"database client connections\":\"190\"}]";
+
+        //Initial map
+        LinkedHashMap<String, Object> map = new LinkedHashMap<>();
+        map.put("mysql service name","mysql200");
+        map.put("mysql address","192.168.xx.xx");
+        map.put("port","3306");
+        map.put("no index of number","80");
+        map.put("database client connections","190");
+
+        //Add map into list
+        list.add(map);
+    }
+
+
+    /**
+     * Test toJsonString
+     */
+    @Test
+    public void testToJsonString() {
+
+        //Invoke toJsonString
+        String result = JSONUtils.toJsonString(list);
+        logger.info(result);
+
+        //Equal result with expected string
+        assertEquals(result,expected);
+
+        //If param is null, then return null string
+        result = JSONUtils.toJsonString(null);
+        logger.info(result);
+
+        assertEquals(result,"null");
+
+    }
+
+    /**
+     * Test toList
+     */
+    @Test
+    public void testToList() {
+
+        //Invoke toList
+        List<LinkedHashMap> result = JSONUtils.toList(expected ,LinkedHashMap.class);
+        //Equal list size=1
+        assertEquals(result.size(),1);
+
+        //Transform entity to LinkedHashMap<String, Object>
+        LinkedHashMap<String, Object> entity = result.get(0);
+
+        //Equal expected values
+        assertEquals(entity.get("mysql service name"),"mysql200");
+        assertEquals(entity.get("mysql address"),"192.168.xx.xx");
+        assertEquals(entity.get("port"),"3306");
+        assertEquals(entity.get("no index of number"),"80");
+        assertEquals(entity.get("database client connections"),"190");
+
+        //If param is null, then return null
+        result = JSONUtils.toList(null ,LinkedHashMap.class);
+        assertNull(result);
+
+        //If param is incorrect, then return null and log error message
+        result = JSONUtils.toList("}{" ,LinkedHashMap.class);
+        assertNull(result);
+
+    }
+
+}
diff --git a/pom.xml b/pom.xml
index a56fe6e892..4b10ba9c42 100644
--- a/pom.xml
+++ b/pom.xml
@@ -613,14 +613,15 @@
 				<configuration>
 					<includes>
 						<include>**/common/utils/*.java</include>
-						<include>**/api/utils/CheckUtilsTest.java</include>
-						<include>**/api/utils/FileUtilsTest.java</include>
 
 						<include>**/common/graph/*.java</include>
 						<include>**/common/queue/*.java</include>
 						<include>**/api/utils/CheckUtilsTest.java</include>
 						<include>**/api/utils/FileUtilsTest.java</include>
-            <include>**/alert/utils/ExcelUtilsTest.java</include>
+
+						<include>**/alert/utils/ExcelUtilsTest.java</include>
+						<include>**/alert/utils/FuncUtilsTest.java</include>
+						<include>**/alert/utils/JSONUtilsTest.java</include>
 					</includes>
 					<!-- <skip>true</skip> -->
 				</configuration>