org.zeromq

Class ZMQ

java.lang.Object

org.zeromq.ZMQ

public class ZMQ
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ZMQ.Context
static class	ZMQ.Error
static class	ZMQ.Event Inner class: Event.
static class	ZMQ.Poller
static class	ZMQ.PollItem
static class	ZMQ.Socket

Field Summary

Fields

Modifier and Type	Field and Description
static Charset	CHARSET
static int	DEALER Flag to specify a DEALER socket (aka XREQ).
static int	DONTWAIT Socket flag to indicate a nonblocking send or recv mode.
static int	DOWNSTREAM Deprecated.
static int	EVENT_ACCEPT_FAILED EVENT_ACCEPT_FAILED: could not accept client connection.
static int	EVENT_ACCEPTED EVENT_ACCEPTED: connection accepted to bound interface.
static int	EVENT_ALL EVENT_ALL: all events known.
static int	EVENT_BIND_FAILED EVENT_BIND_FAILED: socket could not bind to an address.
static int	EVENT_CLOSE_FAILED EVENT_CLOSE_FAILED: connection couldn't be closed.
static int	EVENT_CLOSED EVENT_CLOSED: connection closed.
static int	EVENT_CONNECT_DELAYED EVENT_CONNECT_DELAYED: synchronous connect failed, it's being polled.
static int	EVENT_CONNECT_RETRIED EVENT_CONNECT_RETRIED: asynchronous connect / reconnection attempt.
static int	EVENT_CONNECTED EVENT_CONNECTED: connection established.
static int	EVENT_DELAYED Deprecated.
static int	EVENT_DISCONNECTED EVENT_DISCONNECTED: broken session.
static int	EVENT_LISTENING EVENT_LISTENING: socket bound to an address, ready to accept connections.
static int	EVENT_MONITOR_STOPPED EVENT_MONITOR_STOPPED: monitor has been stopped.
static int	EVENT_RETRIED Deprecated.
static int	FORWARDER Flag to specify a FORWARDER device.
static byte[]	MESSAGE_SEPARATOR
static int	NOBLOCK
static int	PAIR Flag to specify a exclusive pair of sockets.
static int	PUB Flag to specify a PUB socket, receiving side must be a SUB or XSUB.
static int	PULL Flag to specify the receiving part of a PUSH socket.
static int	PUSH Flag to specify a PUSH socket, receiving side must be a PULL.
static int	QUEUE Flag to specify a QUEUE device.
static int	REP Flag to specify the receiving part of a REQ socket.
static int	REQ Flag to specify a REQ socket, receiving side must be a REP.
static int	ROUTER Flag to specify ROUTER socket (aka XREP).
static int	SNDMORE Socket flag to indicate that more message parts are coming.
static int	STREAMER Flag to specify a STREAMER device.
static int	SUB Flag to specify the receiving part of the PUB or XPUB socket.
static byte[]	SUBSCRIPTION_ALL
static int	UPSTREAM Deprecated.
static int	XPUB Flag to specify a XPUB socket, receiving side must be a SUB or XSUB.
static int	XREP Deprecated. As of release 3.0 of zeromq, replaced by ROUTER
static int	XREQ Deprecated. As of release 3.0 of zeromq, replaced by DEALER
static int	XSUB Flag to specify the receiving part of the PUB or XPUB socket.

Method Summary

Methods

Modifier and Type	Method and Description
static ZMQ.Context	context(int ioThreads) Create a new Context.
static boolean	device(int type, ZMQ.Socket frontend, ZMQ.Socket backend) Deprecated.
static int	getFullVersion()
static int	getMajorVersion()
static int	getMinorVersion()
static int	getPatchVersion()
static String	getVersionString()
static int	makeVersion(int major, int minor, int patch)
static int	poll(ZMQ.PollItem[] items, int count, long timeout)
static int	poll(ZMQ.PollItem[] items, long timeout)
static boolean	proxy(ZMQ.Socket frontend, ZMQ.Socket backend, ZMQ.Socket capture) Starts the built-in 0MQ proxy in the current application thread.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SNDMORE

public static final int SNDMORE

Socket flag to indicate that more message parts are coming.

See Also:

Constant Field Values

DONTWAIT

public static final int DONTWAIT

Socket flag to indicate a nonblocking send or recv mode.

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Constant Field Values

NOBLOCK

public static final int NOBLOCK

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Constant Field Values

PAIR

public static final int PAIR

Flag to specify a exclusive pair of sockets.

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Constant Field Values

PUB

public static final int PUB

Flag to specify a PUB socket, receiving side must be a SUB or XSUB.

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Constant Field Values

SUB

public static final int SUB

Flag to specify the receiving part of the PUB or XPUB socket.

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Constant Field Values

REQ

public static final int REQ

Flag to specify a REQ socket, receiving side must be a REP.

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Constant Field Values

REP

public static final int REP

Flag to specify the receiving part of a REQ socket.

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Constant Field Values

DEALER

public static final int DEALER

Flag to specify a DEALER socket (aka XREQ). DEALER is really a combined ventilator / sink that does load-balancing on output and fair-queuing on input with no other semantics. It is the only socket type that lets you shuffle messages out to N nodes and shuffle the replies back, in a raw bidirectional asynch pattern.

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Constant Field Values

XREQ

public static final int XREQ

Deprecated. As of release 3.0 of zeromq, replaced by DEALER

Old alias for DEALER flag. Flag to specify a XREQ socket, receiving side must be a XREP.

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Constant Field Values

ROUTER

public static final int ROUTER

Flag to specify ROUTER socket (aka XREP). ROUTER is the socket that creates and consumes request-reply routing envelopes. It is the only socket type that lets you route messages to specific connections if you know their identities.

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Constant Field Values

XREP

public static final int XREP

Deprecated. As of release 3.0 of zeromq, replaced by ROUTER

Old alias for ROUTER flag. Flag to specify the receiving part of a XREQ socket.

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Constant Field Values

PULL

public static final int PULL

Flag to specify the receiving part of a PUSH socket.

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Constant Field Values

PUSH

public static final int PUSH

Flag to specify a PUSH socket, receiving side must be a PULL.

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Constant Field Values

XPUB

public static final int XPUB

Flag to specify a XPUB socket, receiving side must be a SUB or XSUB. Subscriptions can be received as a message. Subscriptions start with a '1' byte. Unsubscriptions start with a '0' byte.

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Constant Field Values

XSUB

public static final int XSUB

Flag to specify the receiving part of the PUB or XPUB socket. Allows

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Constant Field Values

STREAMER

public static final int STREAMER

Flag to specify a STREAMER device.

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Constant Field Values

FORWARDER

public static final int FORWARDER

Flag to specify a FORWARDER device.

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Constant Field Values

QUEUE

public static final int QUEUE

Flag to specify a QUEUE device.

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Constant Field Values

UPSTREAM

@Deprecated
public static final int UPSTREAM

Deprecated.

See Also:

PULL, Constant Field Values

DOWNSTREAM

@Deprecated
public static final int DOWNSTREAM

Deprecated.

See Also:

PUSH, Constant Field Values

EVENT_CONNECTED

public static final int EVENT_CONNECTED

EVENT_CONNECTED: connection established. The EVENT_CONNECTED event triggers when a connection has been established to a remote peer. This can happen either synchronous or asynchronous. Value is the FD of the newly connected socket.

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Constant Field Values

EVENT_CONNECT_DELAYED

public static final int EVENT_CONNECT_DELAYED

EVENT_CONNECT_DELAYED: synchronous connect failed, it's being polled. The EVENT_CONNECT_DELAYED event triggers when an immediate connection attempt is delayed and its completion is being polled for. Value has no meaning.

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Constant Field Values

EVENT_DELAYED

@Deprecated
public static final int EVENT_DELAYED

Deprecated.

See Also:

EVENT_CONNECT_DELAYED, Constant Field Values

EVENT_CONNECT_RETRIED

public static final int EVENT_CONNECT_RETRIED

EVENT_CONNECT_RETRIED: asynchronous connect / reconnection attempt. The EVENT_CONNECT_RETRIED event triggers when a connection attempt is being handled by reconnect timer. The reconnect interval's recomputed for each attempt. Value is the reconnect interval.

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Constant Field Values

EVENT_RETRIED

@Deprecated
public static final int EVENT_RETRIED

Deprecated.

See Also:

EVENT_CONNECT_RETRIED, Constant Field Values

EVENT_LISTENING

public static final int EVENT_LISTENING

EVENT_LISTENING: socket bound to an address, ready to accept connections. The EVENT_LISTENING event triggers when a socket's successfully bound to a an interface. Value is the FD of the newly bound socket.

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Constant Field Values

EVENT_BIND_FAILED

public static final int EVENT_BIND_FAILED

EVENT_BIND_FAILED: socket could not bind to an address. The EVENT_BIND_FAILED event triggers when a socket could not bind to a given interface. Value is the errno generated by the bind call.

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Constant Field Values

EVENT_ACCEPTED

public static final int EVENT_ACCEPTED

EVENT_ACCEPTED: connection accepted to bound interface. The EVENT_ACCEPTED event triggers when a connection from a remote peer has been established with a socket's listen address. Value is the FD of the accepted socket.

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Constant Field Values

EVENT_ACCEPT_FAILED

public static final int EVENT_ACCEPT_FAILED

EVENT_ACCEPT_FAILED: could not accept client connection. The EVENT_ACCEPT_FAILED event triggers when a connection attempt to a socket's bound address fails. Value is the errno generated by accept.

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Constant Field Values

EVENT_CLOSED

public static final int EVENT_CLOSED

EVENT_CLOSED: connection closed. The EVENT_CLOSED event triggers when a connection's underlying descriptor has been closed. Value is the former FD of the for the closed socket. FD has been closed already!

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Constant Field Values

EVENT_CLOSE_FAILED

public static final int EVENT_CLOSE_FAILED

EVENT_CLOSE_FAILED: connection couldn't be closed. The EVENT_CLOSE_FAILED event triggers when a descriptor could not be released back to the OS. Implementation note: ONLY FOR IPC SOCKETS. Value is the errno generated by unlink.

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Constant Field Values

EVENT_DISCONNECTED

public static final int EVENT_DISCONNECTED

EVENT_DISCONNECTED: broken session. The EVENT_DISCONNECTED event triggers when the stream engine (tcp and ipc specific) detects a corrupted / broken session. Value is the FD of the socket.

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Constant Field Values

EVENT_MONITOR_STOPPED

public static final int EVENT_MONITOR_STOPPED

EVENT_MONITOR_STOPPED: monitor has been stopped. The EVENT_MONITOR_STOPPED event triggers when the monitor for a socket is stopped.

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Constant Field Values

EVENT_ALL

public static final int EVENT_ALL

EVENT_ALL: all events known. The EVENT_ALL constant can be used to set up a monitor for all known events.

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Constant Field Values

MESSAGE_SEPARATOR

public static final byte[] MESSAGE_SEPARATOR

SUBSCRIPTION_ALL

public static final byte[] SUBSCRIPTION_ALL

CHARSET

public static final Charset CHARSET

Method Detail

context

public static ZMQ.Context context(int ioThreads)

Create a new Context.

Parameters:

ioThreads - Number of threads to use, usually 1 is sufficient for most use cases.

Returns:

the Context

device

@Deprecated
public static boolean device(int type,
                        ZMQ.Socket frontend,
                        ZMQ.Socket backend)

Deprecated.

proxy

public static boolean proxy(ZMQ.Socket frontend,
            ZMQ.Socket backend,
            ZMQ.Socket capture)

Starts the built-in 0MQ proxy in the current application thread. The proxy connects a frontend socket to a backend socket. Conceptually, data flows from frontend to backend. Depending on the socket types, replies may flow in the opposite direction. The direction is conceptual only; the proxy is fully symmetric and there is no technical difference between frontend and backend. Before calling ZMQ.proxy() you must set any socket options, and connect or bind both frontend and backend sockets. The two conventional proxy models are: ZMQ.proxy() runs in the current thread and returns only if/when the current context is closed.

Parameters:

frontend - ZMQ.Socket

backend - ZMQ.Socket

capture - If the capture socket is not NULL, the proxy shall send all messages, received on both frontend and backend, to the capture socket. The capture socket should be a ZMQ_PUB, ZMQ_DEALER, ZMQ_PUSH, or ZMQ_PAIR socket.

poll

public static int poll(ZMQ.PollItem[] items,
       long timeout)

poll

public static int poll(ZMQ.PollItem[] items,
       int count,
       long timeout)

getMajorVersion

public static int getMajorVersion()

Returns:

Major version number of the ZMQ library.

getMinorVersion

public static int getMinorVersion()

Returns:

Major version number of the ZMQ library.

getPatchVersion

public static int getPatchVersion()

Returns:

Major version number of the ZMQ library.

getFullVersion

public static int getFullVersion()

Returns:

Full version number of the ZMQ library used for comparing versions.

makeVersion

public static int makeVersion(int major,
              int minor,
              int patch)

Parameters:

major - Version major component.

minor - Version minor component.

patch - Version patch component.

Returns:

Comparible single int version number.

getVersionString

public static String getVersionString()

Returns:

String version number in the form major.minor.patch.