Replace TimerTask with ScheduledExecutorService

Author: Noah Andrews

src/main/java/org/java_websocket/AbstractWebSocket.java

@@ -31,8 +31,10 @@
 
 importjava.util.ArrayList;
 importjava.util.Collection;
-importjava.util.Timer;
-importjava.util.TimerTask;
+importjava.util.concurrent.Executors;
+importjava.util.concurrent.ScheduledExecutorService;
+importjava.util.concurrent.ScheduledFuture;
+importjava.util.concurrent.TimeUnit;
 
 
 /**
@@ -60,15 +62,15 @@ public abstract class AbstractWebSocket extends WebSocketAdapter{
 privatebooleanreuseAddr;
 
 /**
- * Attribute for a timer allowing to check for lost connections
- * @since 1.3.4
+ * Attribute for a service that triggers lost connection checking
+ * @since 1.4.1
  */
-privateTimerconnectionLostTimer;
+privateScheduledExecutorServiceconnectionLostCheckerService;
 /**
- * Attribute for a timertask allowing to check for lost connections
- * @since 1.3.4
+ * Attribute for a task that checks for lost connections
+ * @since 1.4.1
  */
-privateTimerTaskconnectionLostTimerTask;
+privateScheduledFutureconnectionLostCheckerFuture;
 
 /**
  * Attribute for the lost connection check interval
@@ -139,7 +141,7 @@ public void setConnectionLostTimeout( int connectionLostTimeout ){
  */
 protectedvoidstopConnectionLostTimer(){
 synchronized (syncConnectionLost){
-if (connectionLostTimer != null || connectionLostTimerTask != null){
+if (connectionLostCheckerService != null || connectionLostCheckerFuture != null){
 this.websocketRunning = false;
 log.trace("Connection lost timer stopped");
 cancelConnectionLostTimer();
@@ -168,8 +170,8 @@ protected void startConnectionLostTimer(){
  */
 privatevoidrestartConnectionLostTimer(){
 cancelConnectionLostTimer();
-connectionLostTimer = newTimer("WebSocketTimer");
-connectionLostTimerTask= newTimerTask(){
+connectionLostCheckerService = Executors.newSingleThreadScheduledExecutor();
+RunnableconnectionLostChecker= newRunnable(){
 
 /**
  * Keep the connections in a separate list to not cause deadlocks
@@ -190,8 +192,8 @@ public void run(){
 connections.clear();
  }
  };
-connectionLostTimer.scheduleAtFixedRate( connectionLostTimerTask,1000L*connectionLostTimeout , 1000L*connectionLostTimeout );
 
+connectionLostCheckerFuture = connectionLostCheckerService.scheduleAtFixedRate(connectionLostChecker, connectionLostTimeout, connectionLostTimeout, TimeUnit.SECONDS);
  }
 
 /**
@@ -228,13 +230,13 @@ private void executeConnectionLostDetection(WebSocket webSocket, long current){
  * @since 1.3.4
  */
 privatevoidcancelConnectionLostTimer(){
-if( connectionLostTimer != null ){
-connectionLostTimer.cancel();
-connectionLostTimer = null;
+if( connectionLostCheckerService != null ){
+connectionLostCheckerService.shutdownNow();
+connectionLostCheckerService = null;
  }
-if( connectionLostTimerTask != null ){
-connectionLostTimerTask.cancel();
-connectionLostTimerTask = null;
+if( connectionLostCheckerFuture != null ){
+connectionLostCheckerFuture.cancel(false);
+connectionLostCheckerFuture = null;
  }
  }