Fix issue #834 by starting WebSocketWorker of the WebSocketServer in the start function

src/main/java/org/java_websocket/server/WebSocketServer.java

@@ -211,7 +211,6 @@ public WebSocketServer( InetSocketAddress address , int decodercount , List<Draf
 		for( int i = 0 ; i < decodercount ; i++ ) {
 			WebSocketWorker ex = new WebSocketWorker();
 			decoders.add( ex );
-			ex.start();
 		}
 	}
 
@@ -229,6 +228,10 @@ public void start() {
 		if( selectorthread != null )
 			throw new IllegalStateException( getClass().getName() + " can only be started once." );
 		new Thread( this ).start();
+
+		for( WebSocketWorker ex : decoders ){
+			ex.start();
+		}
 	}
 
 	/**

src/test/java/org/java_websocket/issues/AllIssueTests.java

@@ -41,7 +41,8 @@
 		org.java_websocket.issues.Issue732Test.class,
 		org.java_websocket.issues.Issue764Test.class,
 		org.java_websocket.issues.Issue765Test.class,
-		org.java_websocket.issues.Issue825Test.class
+		org.java_websocket.issues.Issue825Test.class,
+		org.java_websocket.issues.Issue834Test.class
 })
 /**
  * Start all tests for issues

src/test/java/org/java_websocket/issues/Issue834Test.java

@@ -0,0 +1,50 @@
+package org.java_websocket.issues;
+
+import org.java_websocket.WebSocket;
+import org.java_websocket.handshake.ClientHandshake;
+import org.java_websocket.server.WebSocketServer;
+import org.java_websocket.util.SocketUtil;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.util.Set;
+
+public class Issue834Test {
+
+    @Test(timeout = 1000)
+    public void testNoNewThreads() throws IOException {
+
+        Set<Thread> threadSet1 = Thread.getAllStackTraces().keySet();
+
+        new WebSocketServer(new InetSocketAddress(SocketUtil.getAvailablePort())) {
+            @Override
+            public void onOpen(WebSocket conn, ClientHandshake handshake) {
+            }
+
+            @Override
+            public void onClose(WebSocket conn, int code, String reason, boolean remote) {
+            }
+
+            @Override
+            public void onMessage(WebSocket conn, String message) {
+            }
+
+            @Override
+            public void onError(WebSocket conn, Exception ex) {
+            }
+
+            @Override
+            public void onStart() {
+            }
+        };
+
+        Set<Thread> threadSet2 = Thread.getAllStackTraces().keySet();
+
+        //checks that no threads are started in the constructor
+        Assert.assertEquals(threadSet1, threadSet2);
+
+    }
+
+}