Guys am having some difficulty figuring this out:
I am trying to test whether the code(in c#) to broadcast a message and receiving the message works:
The code to send the datagram(in this case its the hostname) is:
public partial class Form1 : Form
{
String hostName;
byte[] hostBuffer = new byte[1024];
public Form1()
{
InitializeComponent();
StartNotification();
}
public void StartNotification()
{
IPEndPoint notifyIP = new IPEndPoint(IPAddress.Broadcast, 6000);
hostName = Dns.GetHostName();
hostBuffer = Encoding.ASCII.GetBytes(hostName);
UdpClient newUdpClient = new UdpClient();
newUdpClient.Send(hostBuffer, hostBuffer.Length, notifyIP);
}
}
And the code to receive the datagram is:
public partial class Form1 : Form
{
byte[] receivedNotification = new byte[1024];
String notificationReceived;
StringBuilder listBox;
UdpClient udpServer;
IPEndPoint remoteEndPoint;
public Form1()
{
InitializeComponent();
udpServer = new UdpClient(new IPEndPoint(IPAddress.Any, 1234));
remoteEndPoint=null;
startUdpListener1();
}
public void startUdpListener1()
{
receivedNotification = udpServer.Receive(ref remoteEndPoint);
notificationReceived = Encoding.ASCII.GetString(receivedNotification);
listBox = new StringBuilder(this.listBox1.Text);
listBox.AppendLine(notificationReceived);
this.listBox1.Items.Add(listBox.ToString());
}
}
For the reception of the code I have a form that has only a listbox(listBox1).
The problem here is that when i execute the code to receive, the program runs but the form isnt visible.
However when I comment the function call( startUdpListener1() ), the purpose isnt served but the form is visible.
Whats going wrong?
udpServer.Receive() is probably a blocking call, waiting for data (that it isn't getting)
Related
I am new to Spring framework. We have a requirement where our application is acting as a client and needs to integrate with another application using TCP. We will be sending them fixed length requests and we will receive response for the same. We have been asked to use the same TCP connection for each request. Using the same open connection, our application will also be receiving heartbeat messages from server application and we do not need to send any response for them.
The request messages that we need to send is header + body where header has message type and length details.
We will be using SSL. When we try to test with SSL, it does not show any exception during getConnection but is not able to receive any heartbeat messages.
When we test without SSL, it is able to send requests and receive response as well as heartbeat messages. But after the first request response, it sends partial request text to server application for subsequent messages which is causing issues and connections are being reset by peer due to unexpected message received at their end.
I have tried many things referring to online documents available but not able to successfully implement the requirement.
Please find below code. Thanks in advance.
public class ClientConfig implements ApplicationEventPublisherAware{
protected String port;
protected String host;
protected String connectionTimeout;
protected String keyStorePath;
protected String trustStorePath;
protected String keyStorePassword;
protected String trustStorePassword;
protected String protocol;
private ApplicationEventPublisher applicationEventPublisher;
#Override
public void setApplicationEventPublisher(ApplicationEventPublisher applicationEventPublisher) {
this.applicationEventPublisher = applicationEventPublisher;
}
#Bean
public DefaultTcpNioSSLConnectionSupport connectionSupport() {
if("SSL".equalsIgnoreCase(getProtocol())) {
DefaultTcpSSLContextSupport sslContextSupport =
new DefaultTcpSSLContextSupport(getKeyStorePath(),
getTrustStorePath(), getKeyStorePassword(), getTrustStorePassword());
sslContextSupport.setProtocol(getProtocol());
DefaultTcpNioSSLConnectionSupport tcpNioConnectionSupport =
new DefaultTcpNioSSLConnectionSupport(sslContextSupport);
return tcpNioConnectionSupport;
}
return null;
}
#Bean
public AbstractClientConnectionFactory clientConnectionFactory() {
if(StringUtils.isNullOrEmptyTrim(getHost()) || StringUtils.isNullOrEmptyTrim(getPort())) {
return null;
}
TcpNioClientConnectionFactory tcpNioClientConnectionFactory =
new TcpNioClientConnectionFactory(getHost(), Integer.valueOf(getPort()));
tcpNioClientConnectionFactory.setApplicationEventPublisher(applicationEventPublisher);
tcpNioClientConnectionFactory.setSoKeepAlive(true);
tcpNioClientConnectionFactory.setDeserializer(new CustomSerializerDeserializer());
tcpNioClientConnectionFactory.setSerializer(new CustomSerializerDeserializer());
tcpNioClientConnectionFactory.setLeaveOpen(true);
tcpNioClientConnectionFactory.setSingleUse(false);
if("SSL".equalsIgnoreCase(getProtocol())) {
tcpNioClientConnectionFactory.setSslHandshakeTimeout(60);
tcpNioClientConnectionFactory.setTcpNioConnectionSupport(connectionSupport());
}
return tcpNioClientConnectionFactory;
}
#Bean
public MessageChannel outboundChannel() {
return new DirectChannel();
}
#Bean
public PollableChannel receiverChannel() {
return new QueueChannel();
}
#Bean
#ServiceActivator(inputChannel = "outboundChannel")
public TcpSendingMessageHandler outboundClient
(AbstractClientConnectionFactory clientConnectionFactory) {
TcpSendingMessageHandler outbound = new TcpSendingMessageHandler();
outbound.setConnectionFactory(clientConnectionFactory);
if(!StringUtils.isNullOrEmpty(getConnectionTimeout())) {
long timeout = Long.valueOf(getConnectionTimeout());
outbound.setRetryInterval(TimeUnit.SECONDS.toMillis(timeout));
}
outbound.setClientMode(true);
return outbound;
}
#Bean
public TcpReceivingChannelAdapter inboundClient(TcpNioClientConnectionFactory connectionFactory) {
TcpReceivingChannelAdapter inbound = new TcpReceivingChannelAdapter();
inbound.setConnectionFactory(connectionFactory);
if(!StringUtils.isNullOrEmpty(getConnectionTimeout())) {
long timeout = Long.valueOf(getConnectionTimeout());
inbound.setRetryInterval(TimeUnit.SECONDS.toMillis(timeout));
}
inbound.setOutputChannel(receiverChannel());
inbound.setClientMode(true);
return inbound;
}
}
public class CustomSerializerDeserializer implements Serializer<String>, Deserializer<String> {
#Override
public String deserialize(InputStream inputStream) throws IOException {
int i = 0;
byte[] lenbuf = new byte[8];
String message = null;
while ((i = inputStream.read(lenbuf)) != -1) {
String messageType = new String(lenbuf);
if(messageType.contains(APP_DATA_LEN)){
byte byteResp[] = new byte[RESP_MSG_LEN-8];
inputStream.read(byteResp, 0, RESP_MSG_LEN-8);
String readMsg = new String(byteResp);
message = messageType + readMsg;
}else {
byte byteResp[] = new byte[HANDSHAKE_LEN-8];
inputStream.read(byteResp, 0, HANDSHAKE_LEN-8);
String readMsg = new String(byteResp);
message = messageType + readMsg;
}
}
return message;
}
#Override
public void serialize(String object, OutputStream outputStream) throws IOException {
outputStream.write(object.getBytes());
outputStream.flush();
}
}
#Override
public String sendMessage(String message) {
Message<String> request = MessageBuilder.withPayload(message).build();
DirectChannel outboundChannel = (DirectChannel) applicationContext.getBean(DirectChannel.class);
outboundChannel.send(request);
}
//Below code is being used to open connection
TcpNioClientConnectionFactory cf = (TcpNioClientConnectionFactory) applicationContext.getBean(AbstractClientConnectionFactory.class);
if(cf != null) {
TcpNioConnection conn = (TcpNioConnection) cf.getConnection();
}
I have written a netty client code to send some processed data to multiple clients. After running for 3-4 hours I exhaust all sockets and no more connections possible. Also when I check the socket states in the OS a large number of sockets are in TIME_WAIT state.
public class NettyClient {
private static LogHelper logger = new LogHelper(NettyClient.class);
private static EventLoopGroup workerGroup = new NioEventLoopGroup();
private static Bootstrap nettyClient = new Bootstrap()
.group(workerGroup)
.channel(NioSocketChannel.class)
.option(ChannelOption.SO_KEEPALIVE, true)
.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 5000);
private URL url;
private RequestVo Req;
private ChannelFuture chFuture;
private Object ReportData;
private JAXBContext jbContext;
private static final int CHANNEL_READ_TIMEOUT = 5;
public NettyClient() {
// TODO Auto-generated constructor stub
}
public NettyClient(RequestVo Req, JAXBContext jbCtx,Object data) {
this.Req = Req;
this.ReportData = data;
this.jbContext = jbCtx;
}
public void sendRequest() {
logger.debug("In sendRequest()");
//ChannelFuture chFuture = null;
try {
this.url = new URL(Req.getPushAddress());
//add handlers
nettyClient.handler(new ChannelInitializer<SocketChannel>() {
#Override
public void initChannel(SocketChannel ch) {
ch.pipeline()
.addLast("timeout",
new ReadTimeoutHandler(CHANNEL_READ_TIMEOUT, TimeUnit.SECONDS));
ch.pipeline()
.addLast("codec", new HttpClientCodec());
ch.pipeline()
.addLast("inbound",
new NettyClientInBoundHandler(Req, jbContext, ReportData));
}
});
//make a connection to the Client
int port = url.getPort() == -1? url.getDefaultPort():url.getPort();
chFuture = nettyClient.connect(url.getHost(), port);
chFuture.addListener(new NettyClientConnectionListener(this.Req.getRequestId()));
} catch (Exception e) {
logger.error("Exception: Failed to connect to Client ", e);
} finally {
}
}
}
Here are the methods from ChannelInBoundHandler Class
#Override
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception
{
Map<String, String> props = new HashMap<String, String>();
if(msg instanceof HttpResponse) {
logger.debug("channelRead()");
HttpResponse httpRes = (HttpResponse) msg;
HttpResponseStatus httpStatus = httpRes.status();
props.put(REQUEST_ID, this.Request.getRequestId());
props.put(CLIENT_RESPONSE_CODE, String.valueOf(httpStatus.code()));
JmsService.getInstance(DESTINATION).sendTextMessage(props, "");
logger.debug("channelRead() HttpResponse Code: " + httpStatus.code());
ctx.close();
}
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception
{
Map<String, String> props = new HashMap<String, String>();
logger.error("exceptionCaught()", cause);
if(cause instanceof ReadTimeoutException) {
//If read-timeout, send back the response
props.put(REQUEST_ID, this.Request.getRequestId());
props.put(CLIENT_RESPONSE_CODE,
String.valueOf(HttpResponseStatus.REQUEST_TIMEOUT.code()));
JmsService.getInstance(DESTINATION).sendTextMessage(props, "");
ctx.close();
}
else {
logger.error("Exception: ", cause);
}
}
Any idea what is wrong in the code would greatly help me.
Thanks
I'm not familiar with netty, but I think I can explain part of your problem, and hopefully help you along the way:
When you make use of a port and then close it, the port will not automatically be available for use by other processes at once. Instead, it will go into the TIME_WAIT state for a certain period of time. For Windows, I believe this will be 240 seconds (four minutes).
I'd guess that your code is slowly using up all the available ports on your system, due to the release of ports from the TIME_WAIT state is happening too slowly.
It's not entirely clear to me where the actual port numbers are coming from (are they auto-generated by url.getDefaultPort() perhaps?), but perhaps you can find some way to reuse them? If you can keep one or more open connections and somehow reuse these, then you might be able to decrease the frequency of requests for new ports enough for the closed ports to go out of their TIME_WAIT state.
I need to handle emails from about 30 addresses. I implement this in a way where all emails going to one DirectChannel and after to Receiver. In Receiver I can understand from what address is message comes, to do this I create CustomMessageSource that wraps javax.mail.Message to my own type that contains javax.mail.Message and some Enum. Looks like this is not a good decision, cause I can use #Transformer, but how can I use it if I have only 1 channel?
That was the first question.
Second question:
Should I use ONE channel and ONE receiver for all that addresses? Or better to have channel and receiver for each mail address? I don't understand Spring so deeply to feel the difference.
p.s. this question is continuation of Spring multiple imapAdapter
In each child context, you can add a header enricher to set a custom header to the URL from the adapter; with the output channel being the shared channel to the shared service.
In the service, use void foo(Message emailMessage, #Header("myHeader") String url)
I would generally recommend using a single service unless the service needs to do radically different things based on the source.
EDIT:
I modified my answer to your previous question to enhance the original message with the url in a header; each instance has its own header enricher and they all route the enriched message to the common emailChannel.
#Configuration
#EnableIntegration
public class GeneralImapAdapter {
#Value("${imap.url}")
String imapUrl;
#Bean
public static PropertySourcesPlaceholderConfigurer pspc() {
return new PropertySourcesPlaceholderConfigurer();
}
#Bean
#InboundChannelAdapter(value = "enrichHeadersChannel", poller = #Poller(fixedDelay = "10000") )
public MessageSource<javax.mail.Message> mailMessageSource(MailReceiver imapMailReceiver) {
return new MailReceivingMessageSource(imapMailReceiver);
}
#Bean
public MessageChannel enrichHeadersChannel() {
return new DirectChannel();
}
#Bean
#Transformer(inputChannel="enrichHeadersChannel", outputChannel="emailChannel")
public HeaderEnricher enrichHeaders() {
Map<String, ? extends HeaderValueMessageProcessor<?>> headersToAdd =
Collections.singletonMap("emailUrl", new StaticHeaderValueMessageProcessor<>(this.imapUrl));
HeaderEnricher enricher = new HeaderEnricher(headersToAdd);
return enricher;
}
#Bean
public MailReceiver imapMailReceiver() {
MailReceiver receiver = mock(MailReceiver.class);
Message message = mock(Message.class);
when(message.toString()).thenReturn("Message from " + this.imapUrl);
Message[] messages = new Message[] {message};
try {
when(receiver.receive()).thenReturn(messages);
}
catch (MessagingException e) {
e.printStackTrace();
}
return receiver;
}
}
...and I modified the receiving service so it gets access to the header...
#MessageEndpoint
public class EmailReceiverService {
#ServiceActivator(inputChannel="emailChannel")
public void handleMessage(Message message, #Header("emailUrl") String url) {
System.out.println(message + " header:" + url);
}
}
...hope that helps.
EDIT 2:
And this one's a bit more sophisticated; it pulls the from from the payload and puts it in a header; not needed for your use case since you have the full message, but it illustrates the technique...
#Bean
#Transformer(inputChannel="enrichHeadersChannel", outputChannel="emailChannel")
public HeaderEnricher enrichHeaders() {
Map<String, HeaderValueMessageProcessor<?>> headersToAdd = new HashMap<>();
headersToAdd.put("emailUrl", new StaticHeaderValueMessageProcessor<String>(this.imapUrl));
Expression expression = new SpelExpressionParser().parseExpression("payload.from[0].toString()");
headersToAdd.put("from", new ExpressionEvaluatingHeaderValueMessageProcessor<>(expression, String.class));
HeaderEnricher enricher = new HeaderEnricher(headersToAdd);
return enricher;
}
and
#ServiceActivator(inputChannel="emailChannel")
public void handleMessage(Message message, #Header("emailUrl") String url,
#Header("from") String from) {
System.out.println(message + " header:" + url + " from:" + from);
}
I trying to write program, that combines several machines in ring. And after that I send token around this ring. I have a problem: when marker has passed around the ring once and I want to send it second time, machine doesn't want to accept it marker. Sometimes VS rises exception, sort of "... host forcibly closed the connection". Before this problem did not arise at work with asynchronous sockets...
I guess, that problem in listening socket, that work out 1 time and closed. But how can I fix it?
Thanks in advance for your help.
Function, that initializes machines:
private void connectButton_Click(object sender, EventArgs e)
{
if (!connected)
{
//some operation
}
else
{
//some operation
}
try
{
sendS = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
recieveS = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
portFrom = int.Parse(port1TextBox.Text);
portTo = int.Parse(port2TextBox.Text);
}
catch (Exception)
{
port1TextBox.Text = "Incorrect!";
}
IPAddress ipAddressFrom = IPAddress.Parse("192.168.1.122");
IPEndPoint ipEnd = new IPEndPoint(ipAddressFrom, portFrom); //IPAddress.Any
sendS.Bind(ipEnd);
sendS.Listen(1);
sendS.BeginAccept(new AsyncCallback(accept), null);
}
public void accept(IAsyncResult asyn)
{
Socket sock = sendS.EndAccept(asyn);
// Let the worker Socket do the further processing for the just connected client
begin(sock);
// Since the main Socket is now free, it can go back and wait for
// other clients who are attempting to connect
sendS.BeginAccept(new AsyncCallback(accept), null);
}
public class SocketPacket
{
public Socket m_currentSocket;
public byte[] dataBuffer;
// Constructor that takes one argument.
public SocketPacket(int size)
{
dataBuffer = new byte[size];
}
}
public void begin(Socket s)
{
AsyncCallback pfnWorkerCallBack = new AsyncCallback(serialPort1_DataReceived);
SocketPacket theSocPkt = new SocketPacket(15);
theSocPkt.m_currentSocket = s;
s.BeginReceive(theSocPkt.dataBuffer, 0, theSocPkt.dataBuffer.Length, SocketFlags.None, pfnWorkerCallBack, theSocPkt);
}
private void serialPort1_DataReceived(IAsyncResult asyn)
{
SocketPacket socketData = (SocketPacket)asyn.AsyncState;
int iRx = socketData.m_currentSocket.EndReceive(asyn);
byte[] dataBytes = socketData.dataBuffer.ToArray();
for (int i = dataBytes.Length - 1; i > 0; i--)
{
if (dataBytes[i] != 0)
{
Array.Resize(ref dataBytes, i+1);
break;
}
}
Encoding enc = Encoding.GetEncoding(1251);
String text = enc.GetString(dataBytes);
analyze(text);
}
Function, that connects 2 machines:
private void button1_Click(object sender, EventArgs e)
{
if (connected)
{
IPEndPoint ip = new IPEndPoint(IPAddress.Parse(ipTo.Text), System.Convert.ToInt32(portTo));
recieveS.Connect(ip);
}
}
Ok. Solved. I forgot about string
begin(socketData.m_currentSocket);
at the end serialPort1_DataReceived function...
Following the is the code I have for listening to messages from Windows form.
I have noticed that when I click on send it sends a message to MyQueue but at that time I was hoping the event mq_ReceiveCompleted(object sender, ReceiveCompletedEventArgs e) should get called but it is not, in other words I am trying to subscribe to MyQueue from Windows form. Just wondering if I am missing something in the code:
public class Form1 : System.Windows.Forms.Form
{
public System.Messaging.MessageQueue mq;
public static Int32 j=0;
public Form1()
{
// Required for Windows Form Designer support
InitializeComponent();
// Queue Creation
if(MessageQueue.Exists(#".\Private$\MyQueue"))
mq = new System.Messaging.MessageQueue(#".\Private$\MyQueue");
else
mq = MessageQueue.Create(#".\Private$\MyQueue");
mq.ReceiveCompleted += new ReceiveCompletedEventHandler(mq_ReceiveCompleted);
mq.BeginReceive();
}
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
private void btnMsg_Click(object sender, System.EventArgs e)
{
// SendMessage(Handle, 1, 0, IntPtr.Zero);
System.Messaging.Message mm = new System.Messaging.Message();
mm.Body = txtMsg.Text;
mm.Label = "Msg" + j.ToString();
j++;
mq.Send(mm);
}
void mq_ReceiveCompleted(object sender, ReceiveCompletedEventArgs e)
{
//throw new NotImplementedException();
}
private void btnRcv_Click(object sender, System.EventArgs e)
{
System.Messaging.Message mes;
string m;
try
{
mes = mq.Receive(new TimeSpan(0, 0, 3));
mes.Formatter = new XmlMessageFormatter(new String[] {"System.String,mscorlib"});
m = mes.Body.ToString();
}
catch
{
m = "No Message";
}
MsgBox.Items.Add(m.ToString());
}
}
See MSDN's example on how to use the ReceiveCompletedEventHandler .
They have a console app where the Main() does the same as your Form1(), but your handler doesn't have any code. You've said it doesn't call back into your event delegate, but perhaps check your queue name is correct on the constructor.
Consider using MSDN's sample code in a new console app to test your environment first, then go back to your WinForms code with any lessons learned.
private static void MyReceiveCompleted(Object source,
ReceiveCompletedEventArgs asyncResult)
{
MessageQueue mq = (MessageQueue)source;
Message m = mq.EndReceive(asyncResult.AsyncResult);
Console.WriteLine("Message: " + (string)m.Body);
mq.BeginReceive();
return;
}
If you want to inspect the queue and get a message on the click of a button, you can simply move the statement mq.BeginReceive(); to the btnRcv_Click() in place of .Receive();