Class BayeuxClient

All Implemented Interfaces:
org.cometd.bayeux.Bayeux, ClientSession, org.cometd.bayeux.Session, org.eclipse.jetty.util.component.Dumpable

public class BayeuxClient
extends AbstractClientSession
implements org.cometd.bayeux.Bayeux

BayeuxClient is the implementation of a client for the Bayeux protocol.

A BayeuxClient can receive/publish messages from/to a Bayeux server, and it is the counterpart in Java of the JavaScript library used in browsers (and as such it is ideal for Swing applications, load testing tools, etc.).

A BayeuxClient handshakes with a Bayeux server and then subscribes ClientSessionChannel.MessageListener to channels in order to receive messages, and may also publish messages to the Bayeux server.

BayeuxClient relies on pluggable transports for communication with the Bayeux server.

When the communication with the server is finished, the BayeuxClient can be disconnected from the Bayeux server.

Typical usage:

 // Setup Jetty's HttpClient.
 HttpClient httpClient = new HttpClient();
 httpClient.start();

 // Handshake
 String url = "http://localhost:8080/cometd";
 BayeuxClient client = new BayeuxClient(url, new JettyHttpClientTransport(null, httpClient));
 client.handshake();
 client.waitFor(1000, BayeuxClient.State.CONNECTED);

 // Subscription to channels
 ClientSessionChannel channel = client.getChannel("/foo");
 channel.subscribe((channel, message) -> {
     // Handle the message
 });

 // Publishing to channels
 Map<String, Object> data = new HashMap<>();
 data.put("bar", "baz");
 channel.publish(data);

 // Disconnecting
 client.disconnect();
 client.waitFor(1000, BayeuxClient.State.DISCONNECTED);
 
  • Field Details

  • Constructor Details

    • BayeuxClient

      public BayeuxClient​(String url, ClientTransport transport, ClientTransport... transports)

      Creates a BayeuxClient that will connect to the Bayeux server at the given URL and with the given transport(s).

      This constructor allocates a new scheduler; it is recommended that when creating a large number of BayeuxClients a shared scheduler is used.

      Parameters:
      url - the Bayeux server URL to connect to
      transport - the default (mandatory) transport to use
      transports - additional optional transports to use in case the default transport cannot be used
      See Also:
      BayeuxClient(String, ScheduledExecutorService, ClientTransport, ClientTransport...)
    • BayeuxClient

      public BayeuxClient​(String url, ScheduledExecutorService scheduler, ClientTransport transport, ClientTransport... transports)

      Creates a BayeuxClient that will connect to the Bayeux server at the given URL, with the given scheduler and with the given transport(s).

      Parameters:
      url - the Bayeux server URL to connect to
      scheduler - the scheduler to use for scheduling timed operations
      transport - the default (mandatory) transport to use
      transports - additional optional transports to use in case the default transport cannot be used
  • Method Details

    • getURL

      public String getURL()
      Returns:
      the URL passed when constructing this instance
    • getBackOffStrategy

      public BayeuxClient.BackOffStrategy getBackOffStrategy()
    • setBackOffStrategy

      public void setBackOffStrategy​(BayeuxClient.BackOffStrategy backOffStrategy)
    • getCookieStore

      public CookieStore getCookieStore()
    • getCookie

      public HttpCookie getCookie​(String name)

      Retrieves the first cookie with the given name, if available.

      Note that currently only HTTP transports support cookies.

      Parameters:
      name - the cookie name
      Returns:
      the cookie, or null if no such cookie is found
      See Also:
      putCookie(HttpCookie)
    • putCookie

      public void putCookie​(HttpCookie cookie)
    • getId

      public String getId()
      Specified by:
      getId in interface org.cometd.bayeux.Session
    • isHandshook

      public boolean isHandshook()
      Specified by:
      isHandshook in interface org.cometd.bayeux.Session
    • isConnected

      public boolean isConnected()
      Specified by:
      isConnected in interface org.cometd.bayeux.Session
    • isDisconnected

      public boolean isDisconnected()
      Returns:
      whether this BayeuxClient is terminating or disconnected
    • getState

      protected BayeuxClient.State getState()
      Returns:
      the current state of this BayeuxClient
    • handshake

      public void handshake​(ClientSession.MessageListener callback)
      Parameters:
      callback - the message listener to notify of the handshake result
    • handshake

      public void handshake​(Map<String,​Object> fields, ClientSession.MessageListener callback)
      Specified by:
      handshake in interface ClientSession
    • handshake

      public BayeuxClient.State handshake​(long waitMs)

      Performs the handshake and waits at most the given time for the handshake to complete.

      When this method returns, the handshake may have failed (for example because the Bayeux server denied it), so it is important to check the return value to know whether the handshake completed or not.

      Parameters:
      waitMs - the time to wait for the handshake to complete
      Returns:
      the state of this BayeuxClient
      See Also:
      handshake(Map, long)
    • handshake

      public BayeuxClient.State handshake​(Map<String,​Object> template, long waitMs)

      Performs the handshake with the given template and waits at most the given time for the handshake to complete.

      When this method returns, the handshake may have failed (for example because the Bayeux server denied it), so it is important to check the return value to know whether the handshake completed or not.

      Parameters:
      template - the template object to be merged with the handshake message
      waitMs - the time to wait for the handshake to complete
      Returns:
      the state of this BayeuxClient
      See Also:
      handshake(long)
    • sendHandshake

      protected void sendHandshake()
    • waitFor

      public boolean waitFor​(long waitMs, BayeuxClient.State state, BayeuxClient.State... states)

      Waits for this BayeuxClient to reach the given state(s) within the given time.

      Parameters:
      waitMs - the time to wait to reach the given state(s)
      state - the state to reach
      states - additional states to reach in alternative
      Returns:
      true if one of the state(s) has been reached within the given time, false otherwise
    • sendConnect

      protected void sendConnect()
    • newChannelId

      protected org.cometd.bayeux.ChannelId newChannelId​(String channelId)
      Specified by:
      newChannelId in class AbstractClientSession
    • newChannel

      protected AbstractClientSession.AbstractSessionChannel newChannel​(org.cometd.bayeux.ChannelId channelId)
      Specified by:
      newChannel in class AbstractClientSession
    • sendBatch

      protected void sendBatch()
      Specified by:
      sendBatch in class AbstractClientSession
    • sendMessages

      protected void sendMessages​(List<org.cometd.bayeux.Message.Mutable> messages, org.cometd.bayeux.Promise<Boolean> promise)
    • disconnect

      public void disconnect​(ClientSession.MessageListener callback)
      Specified by:
      disconnect in interface ClientSession
    • disconnect

      public boolean disconnect​(long timeout)

      Performs a disconnect and uses the given timeout to wait for the disconnect to complete.

      When a disconnect is sent to the server, the server also wakes up the long poll that may be outstanding, so that a connect reply message may arrive to the client later than the disconnect reply message.

      This method waits for the given timeout for the disconnect reply, but also waits the same timeout for the last connect reply; in the worst case the maximum time waited will therefore be twice the given timeout parameter.

      This method returns true if the disconnect reply message arrived within the given timeout parameter, no matter if the connect reply message arrived or not.

      Parameters:
      timeout - the timeout to wait for the disconnect to complete
      Returns:
      true if the disconnect completed within the given timeout
    • abort

      public void abort()

      Interrupts abruptly the communication with the Bayeux server.

      This method may be useful to simulate network failures.

      See Also:
      ClientSession.disconnect()
    • messagesFailure

      protected void messagesFailure​(Throwable cause, List<? extends org.cometd.bayeux.Message> messages)
    • processHandshake

      protected void processHandshake​(org.cometd.bayeux.Message.Mutable handshake)
    • processConnect

      protected void processConnect​(org.cometd.bayeux.Message.Mutable connect)
    • processDisconnect

      protected void processDisconnect​(org.cometd.bayeux.Message.Mutable disconnect)
    • processMessage

      protected void processMessage​(org.cometd.bayeux.Message.Mutable message)
    • scheduleHandshake

      protected boolean scheduleHandshake​(long interval, long backOff)
    • scheduleConnect

      protected boolean scheduleConnect​(long interval, long backOff)
    • getAllowedTransports

      public List<String> getAllowedTransports()
      Specified by:
      getAllowedTransports in interface org.cometd.bayeux.Bayeux
    • getKnownTransportNames

      public Set<String> getKnownTransportNames()
      Specified by:
      getKnownTransportNames in interface org.cometd.bayeux.Bayeux
    • getTransport

      public ClientTransport getTransport​(String transport)
      Specified by:
      getTransport in interface org.cometd.bayeux.Bayeux
    • getTransport

      public ClientTransport getTransport()
    • initialize

      protected void initialize()
    • terminate

      protected void terminate​(Throwable failure)
    • getOption

      public Object getOption​(String qualifiedName)
      Specified by:
      getOption in interface org.cometd.bayeux.Bayeux
    • setOption

      public void setOption​(String qualifiedName, Object value)
      Specified by:
      setOption in interface org.cometd.bayeux.Bayeux
    • getOptionNames

      public Set<String> getOptionNames()
      Specified by:
      getOptionNames in interface org.cometd.bayeux.Bayeux
    • getOptions

      public Map<String,​Object> getOptions()
      Returns:
      the options that configure with BayeuxClient.
    • send

      protected void send​(org.cometd.bayeux.Message.Mutable message)
      Specified by:
      send in class AbstractClientSession
    • enqueueSend

      protected void enqueueSend​(org.cometd.bayeux.Message.Mutable message)
    • onSending

      public void onSending​(List<? extends org.cometd.bayeux.Message> messages)

      Callback method invoked when the given messages have hit the network towards the Bayeux server.

      The messages may not be modified, and any modification will be useless because the message have already been sent.

      Parameters:
      messages - the messages sent
    • onMessages

      public void onMessages​(List<org.cometd.bayeux.Message.Mutable> messages)

      Callback method invoke when the given messages have just arrived from the Bayeux server.

      The messages may be modified, but it's suggested to use ClientSession.Extensions instead.

      Extensions will be processed after the invocation of this method.

      Parameters:
      messages - the messages arrived
    • onFailure

      public void onFailure​(Throwable failure, List<? extends org.cometd.bayeux.Message> messages)

      Callback method invoked when the given messages have failed to be sent.

      The default implementation logs the failure at DEBUG level.

      Parameters:
      failure - the exception that caused the failure
      messages - the messages being sent
    • onTransportFailure

      protected void onTransportFailure​(org.cometd.bayeux.Message message, ClientTransport.FailureInfo failureInfo, ClientTransport.FailureHandler handler)
    • onTransportFailure

      protected void onTransportFailure​(String oldTransportName, String newTransportName, Throwable failure)
    • toString

      public String toString()
      Overrides:
      toString in class Object