--- a/src/main/java/jp/ac/u_ryukyu/treevnc/CreateConnectionParam.java	Thu May 01 10:20:11 2014 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/treevnc/CreateConnectionParam.java	Thu May 01 18:04:39 2014 +0900
@@ -27,7 +27,7 @@
 		portNumber = 0;
 		do {
 		    try {
-		        Thread runBcast = new Thread(getBcast);
+		        Thread runBcast = new Thread(getBcast, "TreeVNC-root-finder");
 		        runBcast.start();
 		        hostName = getBcast.textAddress(); // wait for root reply to our broadcast
 		        portNumber = Integer.parseInt(getBcast.textPort());

--- a/src/main/java/jp/ac/u_ryukyu/treevnc/client/GetHostClient.java	Thu May 01 10:20:11 2014 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/treevnc/client/GetHostClient.java	Thu May 01 18:04:39 2014 +0900
@@ -30,7 +30,10 @@
 
 	public GetHostClient(String _str) {
 		str = _str;
+	}
 
+	public void createSocket() {
+		
         do {
             try {
                 server = new ServerSocket(port);
@@ -40,9 +43,7 @@
                 // can't open socket
             }
         } while (server == null);
-	}
-
-	public void createSocket() {
+		
 		try {
 			mAddr = InetAddress.getByName(GetBroadCastProxy.McastAddr);
 			soc = new MulticastSocket();
@@ -52,6 +53,10 @@
 		}
 	}
 
+	/**
+	 * send find root message.
+	 * 
+	 */
 	public void sendData() {
 	    String s = str + Integer.toString(port);
 		buf = s.getBytes();
@@ -68,7 +73,13 @@
 		sendData();
 	}
 
+
     
+    /**
+     * @return
+     * reply to findRootMassage
+     * 
+     */
     public String textAddress() {
         return text.getAddress();
     }
@@ -115,9 +126,8 @@
                 text.setButton();
                 text.visible();
             }
-            System.out.println("stop");
+            System.err.println("stop");
         } catch (IOException e) {
-            e.printStackTrace();
         }
     }
 
@@ -127,6 +137,12 @@
     }
     
     public void interrupt() {
+    	stopFlag = true;
+		try {
+			server.close();
+	    	soc.close();
+		} catch (IOException e) {
+		}
         Thread.currentThread().interrupt();
     }