diff --git a/client/src/main/java/com/alibaba/nacos/client/config/filter/impl/ConfigFilterChainManager.java b/client/src/main/java/com/alibaba/nacos/client/config/filter/impl/ConfigFilterChainManager.java
index 8650a0d73..be55bacc3 100644
--- a/client/src/main/java/com/alibaba/nacos/client/config/filter/impl/ConfigFilterChainManager.java
+++ b/client/src/main/java/com/alibaba/nacos/client/config/filter/impl/ConfigFilterChainManager.java
@@ -22,6 +22,7 @@ import com.alibaba.nacos.api.config.filter.IConfigFilterChain;
 import com.alibaba.nacos.api.config.filter.IConfigRequest;
 import com.alibaba.nacos.api.config.filter.IConfigResponse;
 import com.alibaba.nacos.api.exception.NacosException;
+
 import com.google.common.collect.Lists;
 
 /**
@@ -72,8 +73,7 @@ public class ConfigFilterChainManager implements IConfigFilterChain {
 
         @Override
         public void doFilter(final IConfigRequest request, final IConfigResponse response) throws NacosException {
-            if (this.currentPosition == this.additionalFilters.size()) {
-            } else {
+            if (this.currentPosition != this.additionalFilters.size()) {
                 this.currentPosition++;
                 IConfigFilter nextFilter = this.additionalFilters.get(this.currentPosition - 1);
                 nextFilter.doFilter(request, response, this);
diff --git a/client/src/main/java/com/alibaba/nacos/client/config/impl/ServerListManager.java b/client/src/main/java/com/alibaba/nacos/client/config/impl/ServerListManager.java
index f28c00dde..85bd6282d 100644
--- a/client/src/main/java/com/alibaba/nacos/client/config/impl/ServerListManager.java
+++ b/client/src/main/java/com/alibaba/nacos/client/config/impl/ServerListManager.java
@@ -15,21 +15,31 @@
  */
 package com.alibaba.nacos.client.config.impl;
 
+import java.io.IOException;
+import java.io.StringReader;
+import java.net.HttpURLConnection;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Properties;
+import java.util.Random;
+import java.util.concurrent.Callable;
+import java.util.concurrent.TimeUnit;
+
 import com.alibaba.nacos.api.PropertyKeyConst;
 import com.alibaba.nacos.api.SystemPropertyKeyConst;
 import com.alibaba.nacos.api.exception.NacosException;
 import com.alibaba.nacos.client.config.impl.EventDispatcher.ServerlistChangeEvent;
 import com.alibaba.nacos.client.config.impl.HttpSimpleClient.HttpResult;
 import com.alibaba.nacos.client.config.utils.IOUtils;
-import com.alibaba.nacos.client.utils.*;
-import org.slf4j.Logger;
+import com.alibaba.nacos.client.utils.EnvUtil;
+import com.alibaba.nacos.client.utils.LogUtils;
+import com.alibaba.nacos.client.utils.ParamUtil;
+import com.alibaba.nacos.client.utils.StringUtils;
+import com.alibaba.nacos.client.utils.TemplateUtils;
 
-import java.io.IOException;
-import java.io.StringReader;
-import java.net.HttpURLConnection;
-import java.util.*;
-import java.util.concurrent.Callable;
-import java.util.concurrent.TimeUnit;
+import org.slf4j.Logger;
 
 /**
  * Serverlist Manager
@@ -284,8 +294,7 @@ public class ServerListManager {
                 List<String> lines = IOUtils.readLines(new StringReader(httpResult.content));
                 List<String> result = new ArrayList<String>(lines.size());
                 for (String serverAddr : lines) {
-                    if (null == serverAddr || serverAddr.trim().isEmpty()) {
-                    } else {
+                    if (org.apache.commons.lang3.StringUtils.isNotBlank(serverAddr)) {
                         String[] ipPort = serverAddr.trim().split(":");
                         String ip = ipPort[0].trim();
                         if (ipPort.length == 1) {
diff --git a/client/src/main/java/com/alibaba/nacos/client/config/utils/ParamUtils.java b/client/src/main/java/com/alibaba/nacos/client/config/utils/ParamUtils.java
index 55defb6d2..477db7e27 100644
--- a/client/src/main/java/com/alibaba/nacos/client/config/utils/ParamUtils.java
+++ b/client/src/main/java/com/alibaba/nacos/client/config/utils/ParamUtils.java
@@ -43,9 +43,7 @@ public class ParamUtils {
         int length = param.length();
         for (int i = 0; i < length; i++) {
             char ch = param.charAt(i);
-            if (Character.isLetterOrDigit(ch)) {
-            } else if (isValidChar(ch)) {
-            } else {
+            if (!Character.isLetterOrDigit(ch) && !isValidChar(ch)) {
                 return false;
             }
         }
diff --git a/config/src/main/java/com/alibaba/nacos/config/server/service/ServerListService.java b/config/src/main/java/com/alibaba/nacos/config/server/service/ServerListService.java
index cb60eebe1..0a6f36c1d 100644
--- a/config/src/main/java/com/alibaba/nacos/config/server/service/ServerListService.java
+++ b/config/src/main/java/com/alibaba/nacos/config/server/service/ServerListService.java
@@ -15,6 +15,20 @@
  */
 package com.alibaba.nacos.config.server.service;
 
+import java.io.IOException;
+import java.io.StringReader;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.TimeUnit;
+
+import javax.annotation.PostConstruct;
+import javax.servlet.ServletContext;
+import javax.servlet.http.HttpServletResponse;
+
 import com.alibaba.nacos.config.server.constant.Constants;
 import com.alibaba.nacos.config.server.monitor.MetricsMonitor;
 import com.alibaba.nacos.config.server.service.notify.NotifyService;
@@ -23,6 +37,7 @@ import com.alibaba.nacos.config.server.utils.LogUtil;
 import com.alibaba.nacos.config.server.utils.PropertyUtil;
 import com.alibaba.nacos.config.server.utils.RunningConfigUtils;
 import com.alibaba.nacos.config.server.utils.event.EventDispatcher;
+
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.http.HttpResponse;
@@ -39,20 +54,11 @@ import org.springframework.core.env.Environment;
 import org.springframework.stereotype.Service;
 import org.springframework.util.CollectionUtils;
 
-import javax.annotation.PostConstruct;
-import javax.servlet.ServletContext;
-import javax.servlet.http.HttpServletResponse;
-import java.io.IOException;
-import java.io.StringReader;
-import java.util.*;
-import java.util.concurrent.ThreadFactory;
-import java.util.concurrent.TimeUnit;
-
+import static com.alibaba.nacos.config.server.utils.LogUtil.defaultLog;
+import static com.alibaba.nacos.config.server.utils.LogUtil.fatalLog;
 import static com.alibaba.nacos.core.utils.SystemUtils.LOCAL_IP;
 import static com.alibaba.nacos.core.utils.SystemUtils.STANDALONE_MODE;
 import static com.alibaba.nacos.core.utils.SystemUtils.readClusterConf;
-import static com.alibaba.nacos.config.server.utils.LogUtil.defaultLog;
-import static com.alibaba.nacos.config.server.utils.LogUtil.fatalLog;
 
 /**
  * Serverlist service
@@ -261,8 +267,7 @@ public class ServerListService implements ApplicationListener<WebServerInitializ
                     List<String> lines = IOUtils.readLines(new StringReader(result.content));
                     List<String> ips = new ArrayList<String>(lines.size());
                     for (String serverAddr : lines) {
-                        if (null == serverAddr || serverAddr.trim().isEmpty()) {
-                        } else {
+                        if (StringUtils.isNotBlank(serverAddr)) {
                             ips.add(getFormatServerAddr(serverAddr));
                         }
                     }
diff --git a/config/src/main/java/com/alibaba/nacos/config/server/utils/ParamUtils.java b/config/src/main/java/com/alibaba/nacos/config/server/utils/ParamUtils.java
index 413ef404b..793810ed7 100644
--- a/config/src/main/java/com/alibaba/nacos/config/server/utils/ParamUtils.java
+++ b/config/src/main/java/com/alibaba/nacos/config/server/utils/ParamUtils.java
@@ -15,11 +15,12 @@
  */
 package com.alibaba.nacos.config.server.utils;
 
-import com.alibaba.nacos.config.server.exception.NacosException;
-import org.apache.commons.lang3.StringUtils;
-
 import java.util.Map;
 
+import com.alibaba.nacos.config.server.exception.NacosException;
+
+import org.apache.commons.lang3.StringUtils;
+
 /**
  * 参数合法性检查工具类
  *
@@ -46,9 +47,7 @@ public class ParamUtils {
         int length = param.length();
         for (int i = 0; i < length; i++) {
             char ch = param.charAt(i);
-            if (Character.isLetterOrDigit(ch)) {
-            } else if (isValidChar(ch)) {
-            } else {
+            if (!Character.isLetterOrDigit(ch) && !isValidChar(ch)) {
                 return false;
             }
         }