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Can I clean the value of the map in the Netty's ChannelHandler with a periodic timer task?

I define a schedule task in the main thread, I want to clean the value of the map which caches my project's client information in ChannelHandler. But it doesn't work. What did I do wrong?
This is main app code where I schedule a task.
public class Server {
public static void main(String[] args) throws Exception {
EventLoopGroup boss = new NioEventLoopGroup();
EventLoopGroup work = new NioEventLoopGroup();
final ScheduledExecutorService scheduled = Executors.newScheduledThreadPool(1);
ServerBootstrap b = new ServerBootstrap();
//init() code Omitted
ScheduledFuture<?> sf = ctx.executor().scheduleAtFixedRate(new Runnable() {
#Override
public void run() {
HashSet<String> clients = new HashSet<>();
Map<String,String> map = LoginAuthRespHandler.getNodeCheck();
System.out.println(map.size());
for (String key:map.keySet()) {
clients.add(map.get(key));
}
try{
//doSomething();
}catch (Exception e){
e.printStackTrace();
}
map.clear();
clients.clear();
}
},10,10,TimeUnit.SECONDS);
ChannelFuture cf = b.bind(NettyConstant.REMOTEIP,NettyConstant.PORT).sync();
System.out.println("Netty server start ok on: "
+ (NettyConstant.REMOTEIP + " : " + NettyConstant.PORT));
cf.channel().closeFuture().sync();
work.shutdownGracefully();
boss.shutdownGracefully();
}
}
And this is the ChannelHandler code.
public class LoginAuthRespHandler extends ChannelInboundHandlerAdapter {
private static final Logger LOGGER = LoggerFactory.getLogger(LoginAuthRespHandler.class);
private static Map<String, String> nodeCheck = new ConcurrentHashMap<String, String>();
private String[] whiteList = { "127.0.0.1", "192.168.56.1" };
#Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
AlarmMessage message = (AlarmMessage) msg;
if (message.getHeader() != null && message.getHeader().getType() == MessageType.LOGIN_REQ.value()) {
String nodeIndex = ctx.channel().remoteAddress().toString();
AlarmMessage loginResp = null;
if (nodeCheck.containsKey(nodeIndex)) {
loginResp = buildResponse(ResultType.FAIL);
} else {
InetSocketAddress address = (InetSocketAddress) ctx.channel().remoteAddress();
String ip = address.getAddress().getHostAddress();
boolean isOK = false;
for (String WIP : whiteList) {
if (WIP.equals(ip)) {
isOK = true;
break;
}
}
loginResp = isOK ? buildResponse(ResultType.SUCCESS) : buildResponse(ResultType.FAIL);
if (isOK)
//add a client value to the map
nodeCheck.put(nodeIndex, message.getBody().toString());
}
ctx.writeAndFlush(loginResp);
} else {
ctx.fireChannelRead(msg);
}
}
private AlarmMessage buildResponse(ResultType result) {
AlarmMessage message = new AlarmMessage();
Header header = new Header();
header.setType(MessageType.LOGIN_RESP.value());
message.setHeader(header);
message.setBody(result.value());
return message;
}
#Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
String nodeIndex = ctx.channel().remoteAddress().toString();
ctx.close();
if(nodeCheck.containsKey(nodeIndex)){
nodeCheck.remove(nodeIndex);
}
}
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
cause.printStackTrace();
//nodeCheck.remove(ctx.channel().remoteAddress().toString());
ctx.close();
ctx.fireExceptionCaught(cause);
}
public synchronized static Map<String, String> getNodeCheck() {
return nodeCheck;
}
}

FileZilla won't react on commands from my java FTP server

I write my own Java FTP server. Until recently I used PUttY to debug my control telnet connection and everything seemed fine - I had successful two-way communication. Now I try to debug my server with FileZilla, but it does not seem to read my text, nor to send some to server, so it just hangs and wait for something.
Control connection class
public class ControlConnection extends Thread {
private enum OperationMode {
ACTIVE, PASSIVE
}
private final Map<String, Supplier<String>> COMMANDS;
private String[] userTokens;
private User user;
private String userLogin;
private boolean authenticated;
private boolean dataConnected;
private boolean userExists;
private final Socket socket;
private DataInputStream inputStream;
private DataOutputStream outputStream;
private DataConnection ftpSession;
private OperationMode operationMode;
private String errorMessage;
public ControlConnection(Socket socket) {
super(ControlConnection.class.toString());
this.socket = socket;
// constants initialization
authenticated = false;
dataConnected = false;
// commands initialization
COMMANDS = new HashMap<>();
// commands init
}
#Override
public void run() {
try {
inputStream = new DataInputStream(socket.getInputStream());
outputStream = new DataOutputStream(socket.getOutputStream());
sendGreetings();
IOProcessing.writeBytes(outputStream, pasvCommand());;
boolean running = true;
while (running) {
sendGreetings();
String input = IOProcessing.readBytes(inputStream);
if (!(input.equals("")))
System.out.println(input);
if (!checkInput(input))
continue;
userTokens = input.split(" ");
String command = userTokens[0].toUpperCase();
String answer = COMMANDS.get(command).get();
outputStream.writeBytes(answer);
}
}
catch (IOException e) {
System.err.println(e);
System.exit(-1);
}
}
private boolean commonCheck() {
// some checks
return true;
}
private String getErrorMessage() {
return errorMessage;
}
public void sendGreetings() {
String greetings = String.format("220 Control connection established: %s", getConnectionInfo());
IOProcessing.writeBytes(outputStream, greetings);
}
public String getConnectionInfo() {
String info = String.format("%s: %d %s",
socket.getInetAddress().toString(), socket.getPort(), user != null ? user.getUsername(): "");
return info;
}
// input/output proccessing functions
public boolean checkInput(String input) {
// checks
return true;
}
// commands functions
private String pasvCommand() {
if (operationMode == OperationMode.PASSIVE) {
errorMessage = "Already in passive mode.%n";
return errorMessage;
}
String answer;
new ListenToSocket().start();
answer = String.format("227 Entering Passive Mode (%s, %d)",
"127.0.0.1", DataConnection.PORT);
operationMode = OperationMode.PASSIVE;
return answer;
}
private class ListenToSocket extends Thread {
public ListenToSocket() {
}
#Override
public void run() {
try {
ServerSocket ftpSocket =
new ServerSocket(DataConnection.PORT);
ftpSession =
DataConnection.getDataConnection(ftpSocket.accept());
if (ftpSession != null) {
ftpSession.start();
dataConnected = true;
String greetings = "Data connection established: " + ftpSession.getConnectionInfo();
IOProcessing.writeBytes(outputStream, greetings);
} else {
dataConnected = false;
}
} catch (IOException e) {
System.out.print(e);
}
}
}
also, server does not get user credentials, entered in FileZilla - input from server is always empty
IOProcessing class
public class IOProcessing {
private static final Charset UTF8_CHARSET;
static {
UTF8_CHARSET = Charset.forName("UTF-8");
}
public static String readBytes(DataInputStream inputStream) {
String result = "";
try {
int len = inputStream.available();
if (len == 0) {
return result;
}
byte[] byteInput = new byte[len];
inputStream.readFully(byteInput, 0, len);
result = new String(byteInput, "UTF-8").trim();
} catch (IOException e) {
System.err.println(e);
}
return result;
}
output FileZlla log
Status: Resolving address of localhost
Status: Connecting to [::1]:21...
Status: Connection established, waiting for welcome message.

You didn't show us the writeBytes. So I can only guess that you are not sending \r\n after the messages sent to the client. Particularly after the welcome message. So FileZilla keeps waiting forever for it, as any FTP client would do.

how to receive source IP address from multiple snmp traps with snmp4j

i'm using snmp4j to capture trap data from multiple routers,but i don't know how to receive the source IP address from these routers, which router is the sender. That's my code below, maybe it's useful:
public class SNMPTrapReceiver implements CommandResponder {
private MultiThreadedMessageDispatcher dispatcher;
private Snmp snmp = null;
private Address listenAddress;
private ThreadPool threadPool;
private int n = 0;
public SNMPTrapReceiver() {
}
public static void main(String[] args) {
new SNMPTrapReceiver().run();
}
private void run() {
try {
init();
snmp.addCommandResponder(this);
} catch (Exception ex) {
ex.printStackTrace();
}
}
private void init() throws UnknownHostException, IOException {
threadPool = ThreadPool.create("Trap", 10);
dispatcher = new MultiThreadedMessageDispatcher(threadPool,
new MessageDispatcherImpl());
listenAddress = GenericAddress.parse(System.getProperty(
"snmp4j.listenAddress", "udp:0.0.0.0/162"));
TransportMapping<?> transport;
if (listenAddress instanceof UdpAddress) {
transport = new DefaultUdpTransportMapping(
(UdpAddress) listenAddress);
} else {
transport = new DefaultTcpTransportMapping(
(TcpAddress) listenAddress);
}
USM usm = new USM(SecurityProtocols.getInstance(), new OctetString(
MPv3.createLocalEngineID()), 0);
usm.setEngineDiscoveryEnabled(true);
snmp = new Snmp(dispatcher, transport);
snmp.getMessageDispatcher().addMessageProcessingModel(new MPv1());
snmp.getMessageDispatcher().addMessageProcessingModel(new MPv2c());
snmp.getMessageDispatcher().addMessageProcessingModel(new MPv3(usm));
SecurityModels.getInstance().addSecurityModel(usm);
snmp.getUSM().addUser(
new OctetString("MD5DES"),
new UsmUser(new OctetString("MD5DES"), AuthMD5.ID,
new OctetString("UserName"), PrivDES.ID,
new OctetString("PasswordUser")));
snmp.getUSM().addUser(new OctetString("MD5DES"),
new UsmUser(new OctetString("MD5DES"), null, null, null, null));
snmp.listen();
}
public void processPdu(CommandResponderEvent event) {
StringBuffer msg = new StringBuffer();
msg.append(event.toString());
Vector<? extends VariableBinding> varBinds = event.getPDU()
.getVariableBindings();
if (varBinds != null && !varBinds.isEmpty()) {
Iterator<? extends VariableBinding> varIter = varBinds.iterator();
while (varIter.hasNext()) {
VariableBinding var = varIter.next();
msg.append(var.toString()).append(";");
}
}
System.out.println("Message Received: " + msg.toString());
}
}

The CommandResponderEvent contains the sender address in the getPeerAddress() member:
See http://www.snmp4j.org/doc/org/snmp4j/CommandResponderEvent.html#getPeerAddress()
If the trap was forwarded by a proxy, the snmpTrapAddress.0 variable binding (defined in the SNMP-COMMUNITY-MIB, RFC3584) will contain the address of the original trap sender.

JAVA Send an object to all clients

I try to make a chat. When a client send a message to the server, it is working, the server receives the message. So I would like to send this message all the clients. I tried many things but they are not working... Just the client which sends the message, it receives this message
Can You help me please ?
Thanks in advance
PS : Sorry for my bad English
This is the result in the console :
http://i.stack.imgur.com/VS2wf.png
MainClient
public class MainClient {
/**
* #param args the command line arguments
* #throws java.io.IOException
* #throws java.lang.ClassNotFoundException
*/
public static void main(String[] args) throws IOException, ClassNotFoundException {
boolean stop = false;
Socket socket;
Scanner nickScan;
String nick;
socket = new Socket(InetAddress.getLocalHost(), 2009);
System.out.println("Hi, what is your name ?");
nickScan = new Scanner(System.in);
nick = nickScan.nextLine();
User u = new User(nick, false, false, true);
ObjectOutputStream oos = new ObjectOutputStream(socket.getOutputStream());
oos.writeObject(u);
EmissionThread e = new EmissionThread(u, socket);
e.start();
while(!stop){
ObjectInputStream ois = new ObjectInputStream(socket.getInputStream());
Message m = (Message)ois.readObject();
System.out.println(m.getNick() + " : " + m.getMsg());
}
//socket.close();//On ferme les connexions
}
}
MainServer
public class MainServer extends Thread {
public static void main(String[] args) throws InterruptedException, IOException {
// TODO code application logic here
ConnectionThread c = new ConnectionThread();
c.start();
}
}
ConnectionThread
public class ConnectionThread extends Thread {
private static final boolean stop = false;
Socket socketduserveur;
ServerSocket socketserver;
Session s = new Session("#upec");
public ConnectionThread() throws IOException {
this.socketserver = new ServerSocket(2009);
}
public ServerSocket getSocketserver() {
return socketserver;
}
#Override
public void run() {
while (!stop) {
try {
socketduserveur = socketserver.accept(); //On accepte les connexions
ObjectInputStream ois = new ObjectInputStream(socketduserveur.getInputStream());
User u = (User)ois.readObject();
System.out.println(u.getNick() + " c'est connecté");
s.addUserList(u);
if (s.listAlone()) {
System.out.println("Vous etes admin");
u.setAdmin(true);
}
ReceptionThread r = new ReceptionThread(socketduserveur);
r.start();
} catch (ClassNotFoundException ex) {
Logger.getLogger(MainServer.class.getName()).log(Level.SEVERE, null, ex);
} catch (IOException ex) {
Logger.getLogger(ConnectionThread.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
}
ReceptionThread
public class ReceptionThread extends Thread {
private static final boolean stop = false;
Socket socketduserveur;
ServerSocket socketserver;
public ReceptionThread(Socket socketduserveur) {
this.socketduserveur = socketduserveur;
}
#Override
public void run() {
while (!stop) {
try {
ObjectInputStream ois = new ObjectInputStream(socketduserveur.getInputStream());
Message m = (Message)ois.readObject();
System.out.println(m.getNick() + " : " + m.getMsg());
ObjectOutputStream oos = new ObjectOutputStream(socketduserveur.getOutputStream());
oos.writeObject(m);
} catch (IOException | ClassNotFoundException ex) {
Logger.getLogger(ReceptionThread.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
}
EmissionThread
public class EmissionThread extends Thread {
private User u;
private Socket socketduserveur;
private static final boolean stop = false;
public EmissionThread(User u, Socket socketduserveur) {
this.u = u;
this.socketduserveur = socketduserveur;
}
#Override
public void run() {
while (!stop) {
try {
Scanner msgScan;
String msg;
msgScan = new Scanner(System.in);
msg = msgScan.nextLine();
Message m = new Message(u.getNick(), msg);
ObjectOutputStream oos = new ObjectOutputStream(socketduserveur.getOutputStream());
oos.writeObject(m);
} catch (IOException ex) {
Logger.getLogger(EmissionThread.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
}
Message
public class Message implements Serializable {
private String nick;
private String msg;
public Message(String nick, String msg) {
this.nick = nick;
this.msg = msg;
}
}
Session
public class Session implements Serializable {
private String name;
private ArrayList<String> listSession = new ArrayList();
private ArrayList<User> listUser = new ArrayList();
public Session(String name) {
this.name = name;
}
public void addSession(String name){
listSession.add(name);
}
public void deleteSession(String name){
for(String s : listSession){
if(name.equals(s)){
listSession.remove(s);
}
}
}
public boolean existSession(String name){
for(String s : listSession){
if(name.equals(s)){
return true;
}
}
return false;
}
public void addUserList(User u){
listUser.add(u);
}
public boolean listAlone(){
int compteur = 0;
for(User u : listUser){
compteur++;
}
return compteur == 1;
}
}
User
public class User implements Serializable {
private String nick;
private final Session session;
private boolean admin, moderator, voice;
public User(String nick, boolean admin, boolean moderator, boolean voice) {
this.nick = nick;
this.admin = admin;
this.moderator = moderator;
this.voice = voice;
this.session = new Session("#upec");
}
}

You can use websockets on tomcat for this. If you download tomcat there is a chat app already built as an example

JSch upload with progress monitor

I try to implement a SFTP upload with a progress bar.
Unfortunately the progress bar is not updated...
Here is a part of my code:
public class MainView extends JFrame implements SftpProgressMonitor {
private static final Logger LOG = Logger.getLogger(MainView.class);
private String _source;
private JProgressBar _progressBar;
private JButton _button;
public MainView() {
initComponents();
}
void initComponents() {
_button = new JButton("Send");
_button.addActionListener(new ActionListener() {
// If clicked, send event to controller...
});
_progressBar = new JProgressBar();
// Do init stuff here
// ...
}
#Override
public boolean count(long byteTransfered) {
int transfered = _progressBar.getValue();
transfered += byteTransfered;
_progressBar.setValue(transfered);
return true;
}
#Override
public void end() {
LOG.info("Transfer of "+_source+" finished!");
}
#Override
public void init(int op, String src, String dest, long max) {
_progressBar.setValue(0);
_progressBar.setMinimum(0);
_progressBar.setMaximum((int) max);
_source = src;
}
}
public class Controller {
private final MainView _view;
private final SftpClient _ftp;
private final Server _server;
public Controller() {
_server = new Server("192.168.0.1");
_view = new MainView();
_ftp = new SftpClient(_server);
_view.setVisible(true);
}
public void send() {
Executor executor = Executors.newSingleThreadExecutor();
executor.execute(new Runnable() {
public void run() {
File testFile = new File("/PathToFile/file.txt");
String remoteDir = "/MyRemoteDir/";
_ftp.put(testFile, remoteDir, testFile.getName(), _view);
}
});
}
public static void main(String[] args) {
Controller controller = new Controller();
}
}
public class SftpClient {
private static final Logger LOG = Logger.getLogger(SftpClient.class);
/** Connection port number */
public static final int PORT = 22;
/** SECURED protocol name */
public static final String PROTOCOL = "sftp";
/** Connection time out in milliseconds */
public static final int TIME_OUT = 3000;
private Server _server;
/** This class serves as a central configuration point, and as a factory for Session objects configured with these settings */
private JSch _client;
/** A session represents a connection to a SSH server */
private Session _session;
/** Channel connected to a SECURED server (as a subsystem of the SSH server) */
private ChannelSftp _channelSftp;
/**
* Value returned by the last executed command.
*/
private int _exitValue;
public SftpClient(Server server) {
_client = new JSch();
_server = server;
}
protected void connect() throws AuthenticationException, Exception {
try {
if (_client == null) {
_client = new JSch();
}
if (_session == null) {
_session = _client.getSession(_server.getLogin(), _server.getAddress(), PORT);
_session.setConfig("StrictHostKeyChecking", "no");
_session.setPassword(_server.getPassword());
if (LOG.isDebugEnabled()) {
LOG.debug("Connecting to "+_server.getAddress()+" with login "+_server.getLogin()+"...");
}
}
if (!_session.isConnected()) {
_session.connect(TIME_OUT);
}
if(_channelSftp == null || _channelSftp.isConnected() == false) {
Channel c = _session.openChannel(PROTOCOL);
c.connect();
// disconnect previous channel if it has not been killed properly
if (_channelSftp != null && _channelSftp.isConnected()) {
_channelSftp.disconnect();
}
_channelSftp = (ChannelSftp) c;
}
if (LOG.isInfoEnabled()) {
LOG.info("Connected to "+_server.getAddress()+" with login "+_server.getLogin());
}
} catch(JSchException e) {
if ("Auth fail".equals(e.getMessage())) {
throw new AuthenticationException(e);
} else {
throw new Exception(e);
}
}
}
protected void connect(String path) throws AuthenticationException, Exception {
connect();
if (_channelSftp != null && _channelSftp.isConnected()) {
_channelSftp.cd(path);
}
}
#Override
public void disconnect() {
if (_channelSftp != null && _channelSftp.isConnected()) {
_channelSftp.disconnect();
_channelSftp.exit();
}
if (_session != null && _session.isConnected()) {
_session.disconnect();
if (LOG.isInfoEnabled()) {
LOG.info("SECURED FTP disconnected");
}
}
}
#Override
public void put(File localFile, String destPath, SftpProgressMonitor monitor) throws Exception {
put(localFile, destPath, localFile.getName(), monitor);
}
#Override
public void put(File localFile, String destPath, String remoteFileName, SftpProgressMonitor monitor) throws Exception {
if (LOG.isInfoEnabled()) {
LOG.info("Send file "+localFile+" to "+_server+" in "+destPath);
}
if (localFile == null) {
_exitValue = -1;
LOG.error("The given local file is null. Aborting tranfer.");
return;
}
if (!localFile.exists()) {
_exitValue = -1;
LOG.error("'"+localFile+"' doesn't exist. Aborting tranfer.");
return;
}
if(!localFile.canRead()) {
_exitValue = -1;
LOG.error("Cannot read '"+localFile+"'. Aborting tranfer.");
return;
}
final InputStream input = new BufferedInputStream(new FileInputStream(localFile));
if (input == null || input.available() <= 0) {
_exitValue = -1;
LOG.error("Cannot read file "+localFile);
return;
}
try {
connect(destPath);
_channelSftp.put(input, remoteFileName, monitor);
_exitValue = _channelSftp.getExitStatus();
} catch(SftpException e){
throw new IOException(e);
} finally {
if (_channelSftp != null && _channelSftp.isConnected()) {
_channelSftp.disconnect();
_channelSftp.exit();
}
IOUtils.closeQuietly(input);
}
}
}
The count() method is never called. And the source and destination strings of the init contain both -. Am I doing it wrong?

I've changed my code and it works now. I don't use put(InputStream src, String dst, int mode) anymore but put(String src, String dst, SftpProgressMonitor monitor).
I've also implemented a DefaultBoundedRangeModel class. It modifies directly the JProgressBar and it is more interesting for me because I have several files to transfer.
public class ProgressModel extends DefaultBoundedRangeModel implements SftpProgressMonitor {
/** Logger */
private static Logger LOG = Logger.getLogger(ProgressModel.class);
private String _fileBeingTransfered;
/**
* Constructs the model.
*/
public ProgressModel() {
_fileBeingTransfered = "";
}
#Override
public boolean count(long count) {
int value = (int) (getValue() + count);
setValue(value);
fireStateChanged();
if(value < getMaximum()) {
return true;
} else {
return false;
}
}
#Override
public void end() {
LOG.info(_fileBeingTransfered+" transfert finished.");
if(getValue() == getMaximum()) {
LOG.info("All transfers are finished!");
}
}
#Override
public void init(int op, String src, String dest, long max) {
LOG.info("Transfering "+src+" to "+dest+" | size: "+max);
_fileBeingTransfered = src;
}
}
I don't know what caused my problem. Maybe it was the put method.

In order to get updates you have to send reference to monitor to FTP client. And you do this:
_ftp.put(testFile, remoteDir, testFile.getName(), _view);
However what _view is? It is a private final field of class Controller that is never initialized. Therefore it is null. You implemented your callback method count() into class MainView but do not send reference to it to the FTP client. I do not know where do you create instance of Controller but you should pass reference to instance of MainView to it.