diff --git a/Dogename/src/main/java/me/lensferno/dogename/data/Data.java b/Dogename/src/main/java/me/lensferno/dogename/data/Data.java
index f3770d2..6d91439 100644
--- a/Dogename/src/main/java/me/lensferno/dogename/data/Data.java
+++ b/Dogename/src/main/java/me/lensferno/dogename/data/Data.java
@@ -13,18 +13,16 @@ public class Data {
     public static final int IGNORELIST_NAME_ONLY = 0;
     public static final int IGNORELIST_NUMBER_ONLY = 1;
     public static final int IGNORELIST_ALL = 2;
-    File dataFile;
-    SecureRandom secRandom = new SecureRandom();
-    Random random = new Random();
+
+    private final File dataFile = new File(FilePath.toSpecificPathForm("files/Namelist.data"));
+    private final SecureRandom secRandom = new SecureRandom();
+    private final Random random = new Random();
+
     private List<String> nameList;
     private final IgnoreList ignoreList = new IgnoreList();
 
     public Data() {
-
-        dataFile = new File(FilePath.toSpecificPathForm("files/Namelist.data"));
-
         try {
-
             if (!dataFile.exists()) {
                 dataFile.getParentFile().mkdirs();
                 dataFile.createNewFile();
@@ -48,7 +46,6 @@ public Data() {
             System.out.println("Failed to load data file.");
             e.printStackTrace();
         }
-
         ignoreList.readIgnoreList();
     }
 
@@ -90,9 +87,7 @@ public void importNameList(File path) {
                 System.out.println("error in import namelist:" + e);
                 e.printStackTrace();
             }
-
         }
-
     }
 
     public void makeMass() {
@@ -209,7 +204,7 @@ public int getNumberIgnoreListSize() {
         return ignoreList.getNumberIgnoreListSize();
     }
 
-    class IgnoreList {
+    static class IgnoreList {
 
         private final File nameIgnoreFile = new File(FilePath.toSpecificPathForm("files/IgnoredNameList.data"));
         private final File numbIgnoreFile = new File(FilePath.toSpecificPathForm("files/IgnoredNumberList.data"));
@@ -251,7 +246,7 @@ private void writeNumberIgnoreList() {
         public void readIgnoreList() {
             readNameIgnoreList();
             readNumberIgnoreList();
-            System.out.println(String.format("There are %d names and %d numbers ignored", ignoreNameList.size(), ignoreNumberList.size()));
+            System.out.printf("There are %d names and %d numbers ignored", ignoreNameList.size(), ignoreNumberList.size());
         }
 
         private void readNameIgnoreList() {
diff --git a/Dogename/src/main/java/me/lensferno/dogename/data/History.java b/Dogename/src/main/java/me/lensferno/dogename/data/History.java
index 8997b2d..017728f 100644
--- a/Dogename/src/main/java/me/lensferno/dogename/data/History.java
+++ b/Dogename/src/main/java/me/lensferno/dogename/data/History.java
@@ -16,7 +16,6 @@ public void loadHistory() {
         File historyFile = new File(HISTORY_FILE);
 
         try {
-
             if (!historyFile.exists()) {
                 historyFile.getParentFile().mkdirs();
                 historyFile.createNewFile();
@@ -57,7 +56,6 @@ private void writeHistory() {
         File historyFile = new File(HISTORY_FILE);
 
         try {
-
             if (!historyFile.exists()) {
                 historyFile.createNewFile();
             }
diff --git a/Dogename/src/main/java/me/lensferno/dogename/voice/TokenManager.java b/Dogename/src/main/java/me/lensferno/dogename/voice/TokenManager.java
index 0bf53b6..ab54d4d 100644
--- a/Dogename/src/main/java/me/lensferno/dogename/voice/TokenManager.java
+++ b/Dogename/src/main/java/me/lensferno/dogename/voice/TokenManager.java
@@ -32,7 +32,6 @@ private void updateTokenStatus(int statusCode) {
                 if (netAvailable()) {
                     refreshToken();
                 }
-
                 if (checkTokenAvailable() != 0) {
                     tokenStatus = TOKEN_BAD;
                 }
@@ -55,19 +54,13 @@ public void init() {
         if (tokenFile.exists()) {
             loadToken();
             updateTokenStatus(checkTokenAvailable());
-
         } else {
-
             if (netAvailable()) {
-
                 refreshToken();
-
                 updateTokenStatus(checkTokenAvailable());
-
             } else {
                 tokenStatus = TOKEN_BAD;
             }
-
         }
     }
 
@@ -98,17 +91,10 @@ private int checkTokenAvailable() {
         return 0;
     }
 
-
     void fetchToken() {
         try {
             token = new Gson().fromJson(
-                    NetworkUtil.getHtml(
-                            TOKEN_API_URL
-                                    + "?grant_type=client_credentials&client_id=" + API_KEY
-                                    + "&client_secret=" + SEC_KEY,
-                            true)
-                    , Token.class);
-
+                NetworkUtil.getHtml(String.format("%s?grant_type=client_credentials&client_id=%s&client_secret=%s", TOKEN_API_URL, API_KEY, SEC_KEY), true), Token.class);
             token.setExpTime();
         } catch (Exception e) {
             System.out.println("Error to get Token:" + e);
@@ -118,7 +104,6 @@ void fetchToken() {
 
     private boolean netAvailable() {
         try {
-
             URL sourcesURL = new URL("http://www.baidu.com");
             HttpURLConnection connection = (HttpURLConnection) sourcesURL.openConnection();
             connection.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.132 Safari/537.36");
@@ -136,9 +121,8 @@ private boolean netAvailable() {
     }
 
     private void loadToken() {
-        ObjectInputStream ois;
         try {
-            ois = new ObjectInputStream(new FileInputStream(tokenFile));
+            ObjectInputStream ois = new ObjectInputStream(new FileInputStream(tokenFile));
             this.token = (Token) ois.readObject();
             ois.close();
         } catch (Exception e) {
@@ -148,7 +132,6 @@ private void loadToken() {
     }
 
     private void writeToken() {
-
         try {
             ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(tokenFile));
             oos.writeObject(token);
diff --git a/Dogename/src/main/java/me/lensferno/dogename/voice/VoicePlayer.java b/Dogename/src/main/java/me/lensferno/dogename/voice/VoicePlayer.java
index 46e0126..c7ea28b 100644
--- a/Dogename/src/main/java/me/lensferno/dogename/voice/VoicePlayer.java
+++ b/Dogename/src/main/java/me/lensferno/dogename/voice/VoicePlayer.java
@@ -18,7 +18,7 @@ public class VoicePlayer {
 
     Token token;
     StreamPlayer streamPlayer = new StreamPlayer();
-    private VoiceConfig voiceConfig = null;
+    private final VoiceConfig voiceConfig;
 
     public VoicePlayer(Token token, VoiceConfig voiceConfig) {
         this.token = token;