Class BayeuxClient

java.lang.Object
org.cometd.common.AbstractClientSession
org.cometd.client.BayeuxClient
All Implemented Interfaces:
Bayeux, ClientSession, Session, org.eclipse.jetty.util.component.Dumpable
Direct Known Subclasses:
OortComet
public class BayeuxClient extends AbstractClientSession implements 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 uri = "http://localhost:8080/cometd";
BayeuxClient client = new BayeuxClient(uri, 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

      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)

    • getHttpCookieStore

      public org.eclipse.jetty.http.HttpCookieStore getHttpCookieStore()

    • getCookie

      public org.eclipse.jetty.http.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

      public void putCookie(org.eclipse.jetty.http.HttpCookie cookie)

    • getId

      public String getId()
      Description copied from interface: Session

      The clientId of the session.

      This would more correctly be called a "sessionId", but for backwards compatibility with the Bayeux protocol, it is a field called "clientId" that identifies a session.

      Specified by:
      getId in interface Session
      Returns:
      the id of this session

    • isHandshook

      public boolean isHandshook()
      Description copied from interface: Session

      A handshook session is a session where the handshake has successfully completed

      Specified by:
      isHandshook in interface Session
      Returns:
      whether the session is handshook

    • isConnected

      public boolean isConnected()
      Description copied from interface: Session

      A connected session is a session where the link between the client and the server has been established.

      Specified by:
      isConnected in interface Session
      Returns:
      whether the session is connected
      See Also:

    • isDisconnected

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

    • getState

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

    • addTransportListener

      public void addTransportListener(TransportListener listener)
      Parameters:
      listener - the TransportListener to add

    • removeTransportListener

      public void removeTransportListener(TransportListener listener)
      Parameters:
      listener - the TransportListener to remove

    • 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)
      Description copied from interface: ClientSession

      Initiates the bayeux protocol handshake with the server(s).

      The handshake initiated by this method is asynchronous and does not wait for the handshake response.

      Specified by:
      handshake in interface ClientSession
      Parameters:
      fields - additional fields to add to the handshake message.
      callback - the message listener to notify of the handshake result

    • 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

      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:

    • 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 ChannelId newChannelId(String channelId)
      Specified by:
      newChannelId in class AbstractClientSession

    • newChannel

      protected AbstractClientSession.AbstractSessionChannel newChannel(ChannelId channelId)
      Specified by:
      newChannel in class AbstractClientSession

    • sendBatch

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

    • sendMessages

      protected void sendMessages(List<Message.Mutable> messages, Promise<Boolean> promise)

    • disconnect

      public void disconnect(ClientSession.MessageListener callback)
      Description copied from interface: ClientSession

      Disconnects this session, ending the link between the client and the server peers.

      Specified by:
      disconnect in interface ClientSession
      Parameters:
      callback - the message listener to notify of the disconnect result

    • 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:

    • messagesFailure

      protected void messagesFailure(Throwable cause, List<? extends Message> messages)

    • processHandshake

      protected void processHandshake(Message.Mutable handshake)

    • processConnect

      protected void processConnect(Message.Mutable connect)

    • processDisconnect

      protected void processDisconnect(Message.Mutable disconnect)

    • processMessage

      protected void processMessage(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 Bayeux
      Returns:
      the ordered list of transport names that will be used in the negotiation of transports with the other peer.
      See Also:

    • getKnownTransportNames

      public Set<String> getKnownTransportNames()
      Specified by:
      getKnownTransportNames in interface Bayeux
      Returns:
      the set of known transport names of this Bayeux object.
      See Also:

    • getTransport

      public ClientTransport getTransport(String transport)
      Specified by:
      getTransport in interface Bayeux
      Parameters:
      transport - the transport name
      Returns:
      the transport with the given name or null if no such transport exist

    • 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 Bayeux
      Parameters:
      qualifiedName - the configuration option name
      Returns:
      the configuration option with the given qualifiedName
      See Also:

    • setOption

      public void setOption(String qualifiedName, Object value)
      Specified by:
      setOption in interface Bayeux
      Parameters:
      qualifiedName - the configuration option name
      value - the configuration option value
      See Also:

    • getOptionNames

      public Set<String> getOptionNames()
      Specified by:
      getOptionNames in interface Bayeux
      Returns:
      the set of configuration options
      See Also:

    • getOptions

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

    • send

      protected void send(Message.Mutable message)
      Specified by:
      send in class AbstractClientSession

    • enqueueSend

      protected void enqueueSend(Message.Mutable message)

    • onTransportFailure

      protected void onTransportFailure(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