/**
* Connects this channel to a group and gets a state from a specified state provider.
*
* <p>This method invokes {@code connect()} and then {@code getState}.
*
* <p>If the FLUSH protocol is in the channel's stack definition, only one flush round is executed
* for both connecting and fetching the state rather than two flushes if we invoke {@code connect}
* and {@code getState} in succession.
*
* <p>If the channel is already connected, an error message will be printed to the error log. If
* the channel is closed a ChannelClosed exception will be thrown.
*
* @param cluster_name The cluster name to connect to. Cannot be null.
* @param target The state provider. If null, the state will be fetched from the coordinator,
* unless this channel is the coordinator.
* @param timeout The timeout for the state transfer.
* @exception Exception The protocol stack cannot be started, or the JOIN failed
* @exception IllegalStateException The channel is closed or disconnected
* @exception StateTransferException State transfer was not successful
*/
public synchronized void connect(
String cluster_name, Address target, long timeout, boolean useFlushIfPresent)
throws Exception {
if (!_preConnect(cluster_name)) return;
if (cluster_name == null) { // only connect if we are not a unicast channel
state = State.CONNECTED;
return;
}
boolean canFetchState = false;
try {
Event connect_event =
useFlushIfPresent
? new Event(Event.CONNECT_WITH_STATE_TRANSFER_USE_FLUSH, cluster_name)
: new Event(Event.CONNECT_WITH_STATE_TRANSFER, cluster_name);
_connect(connect_event);
state = State.CONNECTED;
notifyChannelConnected(this);
canFetchState = getView() != null && getView().size() > 1;
// if I am not the only member in cluster then
if (canFetchState) getState(target, timeout, false); // fetch state from target
} finally {
// stopFlush if we fetched the state or failed to connect...
if ((flushSupported() && useFlushIfPresent) && (canFetchState || state != State.CONNECTED))
stopFlush();
}
}
/**
* Connects the channel to a group.
*
* @see JChannel#connect(String)
*/
@ManagedOperation(description = "Connects the channel to a group")
protected synchronized void connect(String cluster_name, boolean useFlushIfPresent)
throws Exception {
if (!_preConnect(cluster_name)) return;
if (cluster_name != null) { // only connect if we are not a unicast channel
Event connect_event =
useFlushIfPresent
? new Event(Event.CONNECT_USE_FLUSH, cluster_name)
: new Event(Event.CONNECT, cluster_name);
_connect(connect_event);
}
state = State.CONNECTED;
notifyChannelConnected(this);
}