所有设备指令执行流程修改，保证指令在执行过程中各缓存不会被更改

app/src/main/java/com/bgycc/smartcanteen/command/LogCommandHandler.java

@@ -51,18 +51,14 @@ public class LogCommandHandler extends CommandHandler {
 
     private static LogCommandHandler instance;
 
-    public static LogCommandHandler getInstance(Command command, Gson gson, String deviceSN, CommandProgressCallback callback) {
-        if (instance == null) {
-            synchronized (LogCommandHandler.class) {
+    public static synchronized LogCommandHandler getInstance(Command command, Gson gson, String deviceSN, CommandProgressCallback callback) {
         if (instance == null) {
             instance = new LogCommandHandler(command, gson, deviceSN, callback);
         } else {
+            if (!instance.start) {
                 instance.init(command, gson, deviceSN, callback);
             }
         }
-        } else {
-            instance.init(command, gson, deviceSN, callback);
-        }
         return instance;
     }
 

app/src/main/java/com/bgycc/smartcanteen/command/UpdateCommandHandler.java

@@ -53,18 +53,14 @@ public class UpdateCommandHandler extends CommandHandler {
 
     private static UpdateCommandHandler instance;
 
-    public static UpdateCommandHandler getInstance(Command command, Gson gson, CommandProgressCallback callback) {
-        if (instance == null) {
-            synchronized (UpdateCommandHandler.class) {
+    public static synchronized UpdateCommandHandler getInstance(Command command, Gson gson, CommandProgressCallback callback) {
         if (instance == null) {
             instance = new UpdateCommandHandler(command, gson, callback);
         } else {
+            if (!instance.start) {
                 instance.init(command, gson, callback);
             }
         }
-        } else {
-            instance.init(command, gson, callback);
-        }
         return instance;
     }
 

app/src/main/java/com/bgycc/smartcanteen/command/WifiConfigCommandHandler.java

@@ -19,18 +19,14 @@ public class WifiConfigCommandHandler extends CommandHandler {
     private volatile boolean start = false;
     private static WifiConfigCommandHandler instance;
 
-    public static WifiConfigCommandHandler getInstance(Command command, Gson gson, CommandProgressCallback callback) {
-        if (instance == null) {
-            synchronized (WifiConfigCommandHandler.class) {
+    public static synchronized WifiConfigCommandHandler getInstance(Command command, Gson gson, CommandProgressCallback callback) {
         if (instance == null) {
             instance = new WifiConfigCommandHandler(command, gson, callback);
         } else {
+            if (!instance.start) {
                 instance.init(command, gson, callback);
             }
         }
-        } else {
-            instance.init(command, gson, callback);
-        }
         return instance;
     }