diff --git a/sys/src/test/java/com/alibaba/nacos/sys/env/EnvUtilTest.java b/sys/src/test/java/com/alibaba/nacos/sys/env/EnvUtilTest.java
index e1b2bb9548e..f9fdd2ef216 100644
--- a/sys/src/test/java/com/alibaba/nacos/sys/env/EnvUtilTest.java
+++ b/sys/src/test/java/com/alibaba/nacos/sys/env/EnvUtilTest.java
@@ -1,7 +1,24 @@
+/*
+ * Copyright 1999-2020 Alibaba Group Holding Ltd.
+ *
+ * Licensed 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 com.alibaba.nacos.sys.env;
 
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
+
 import org.junit.jupiter.api.Test;
 import org.mockito.MockedStatic;
 import org.mockito.Mockito;
@@ -25,12 +42,12 @@ void after() {
     }
 
     @Test
-    public void test() {
-        systemBeanManagerMocked.when(() -> OperatingSystemBeanManager.getFreePhysicalMem()).thenReturn(123l);
-        systemBeanManagerMocked.when(() -> OperatingSystemBeanManager.getTotalPhysicalMem()).thenReturn(2048l);
-        assertEquals(EnvUtil.getMem(), 1 - ((double) 123 / (double) 2048));
+    public void testGetMem() {
+        systemBeanManagerMocked.when(() -> OperatingSystemBeanManager.getFreePhysicalMem()).thenReturn(123L);
+        systemBeanManagerMocked.when(() -> OperatingSystemBeanManager.getTotalPhysicalMem()).thenReturn(2048L);
+        assertEquals(EnvUtil.getMem(), 1 - ((double) 123L / (double) 2048L));
 
-        systemBeanManagerMocked.when(() -> OperatingSystemBeanManager.getFreePhysicalMem()).thenReturn(0l);
-        assertEquals(EnvUtil.getMem(), 1 - ((double) 0 / (double) 2048));
+        systemBeanManagerMocked.when(() -> OperatingSystemBeanManager.getFreePhysicalMem()).thenReturn(0L);
+        assertEquals(EnvUtil.getMem(), 1 - ((double) 0L / (double) 2048L));
     }
 }