Package org.zeromq
Class ZMsg
- java.lang.Object
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- org.zeromq.ZMsg
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- All Implemented Interfaces:
java.lang.Iterable<ZFrame>
,java.util.Collection<ZFrame>
,java.util.Deque<ZFrame>
,java.util.Queue<ZFrame>
public class ZMsg extends java.lang.Object implements java.lang.Iterable<ZFrame>, java.util.Deque<ZFrame>
The ZMsg class provides methods to send and receive multipart messages across 0MQ sockets. This class provides a list-like container interface, with methods to work with the overall container. ZMsg messages are composed of zero or more ZFrame objects.// Send a simple single-frame string message on a ZMQSocket "output" socket object ZMsg.newStringMsg("Hello").send(output); // Add several frames into one message ZMsg msg = new ZMsg(); for (int i = 0 ; i < 10 ; i++) { msg.addString("Frame" + i); } msg.send(output); // Receive message from ZMQSocket "input" socket object and iterate over frames ZMsg receivedMessage = ZMsg.recvMsg(input); for (ZFrame f : receivedMessage) { // Do something with frame f (of type ZFrame) }
Based on zmsg.c in czmq
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Constructor Summary
Constructors Constructor Description ZMsg()
Class Constructor
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Modifier and Type Method Description boolean
add(byte[] data)
boolean
add(java.lang.String stringValue)
boolean
add(ZFrame e)
boolean
addAll(java.util.Collection<? extends ZFrame> arg0)
ZMsg
addFirst(byte[] data)
ZMsg
addFirst(java.lang.String stringValue)
void
addFirst(ZFrame e)
ZMsg
addLast(byte[] data)
ZMsg
addLast(java.lang.String stringValue)
void
addLast(ZFrame e)
ZMsg
addString(java.lang.String str)
Add a String as a new ZFrame to the end of listZMsg
append(byte[] data)
Adds bytes as a new frame in the message.ZMsg
append(java.lang.String stringValue)
Adds a string as a new frame in the message.ZMsg
append(ZMsg msg)
void
clear()
boolean
contains(java.lang.Object o)
boolean
containsAll(java.util.Collection<?> arg0)
long
contentSize()
java.util.Iterator<ZFrame>
descendingIterator()
void
destroy()
Destructor.ZMsg
dump()
ZMsg
dump(java.lang.Appendable out)
Dump the message in human readable format.ZMsg
duplicate()
Creates copy of this ZMsg.ZFrame
element()
boolean
equals(java.lang.Object o)
ZFrame
getFirst()
ZFrame
getLast()
int
hashCode()
boolean
isEmpty()
java.util.Iterator<ZFrame>
iterator()
static ZMsg
load(java.io.DataInputStream file)
Load / append a ZMsg from an open DataInputStreamstatic ZMsg
newStringMsg(java.lang.String... strings)
Create a new ZMsg from one or more Stringsboolean
offer(ZFrame e)
boolean
offerFirst(ZFrame e)
boolean
offerLast(ZFrame e)
ZFrame
peek()
ZFrame
peekFirst()
ZFrame
peekLast()
ZFrame
poll()
ZFrame
pollFirst()
ZFrame
pollLast()
ZFrame
pop()
java.lang.String
popString()
Pop a ZFrame and return the toString() representation of it.ZMsg
push(byte[] data)
ZMsg
push(java.lang.String str)
void
push(ZFrame e)
static ZMsg
recvMsg(ZMQ.Socket socket)
Receives message from socket, returns ZMsg object or null if the recv was interrupted.static ZMsg
recvMsg(ZMQ.Socket socket, boolean wait)
Receives message from socket, returns ZMsg object or null if the recv was interrupted.static ZMsg
recvMsg(ZMQ.Socket socket, int flag)
Receives message from socket, returns ZMsg object or null if the recv was interrupted.static void
recvMsg(ZMQ.Socket socket, int flags, Consumer<ZMsg> handler)
This API is in DRAFT state and is subject to change at ANY time until declared stable handle incoming message with a handlerstatic void
recvMsg(ZMQ.Socket socket, int flags, Consumer<ZMsg> handler, Consumer<ZMQException> exceptionHandler)
This API is in DRAFT state and is subject to change at ANY time until declared stable handle incoming message with a handlerZFrame
remove()
boolean
remove(java.lang.Object o)
boolean
removeAll(java.util.Collection<?> arg0)
ZFrame
removeFirst()
boolean
removeFirstOccurrence(java.lang.Object o)
ZFrame
removeLast()
boolean
removeLastOccurrence(java.lang.Object o)
boolean
retainAll(java.util.Collection<?> arg0)
static boolean
save(ZMsg msg, java.io.DataOutputStream file)
Save message to an open data output stream.boolean
send(ZMQ.Socket socket)
Send message to 0MQ socket.boolean
send(ZMQ.Socket socket, boolean destroy)
Send message to 0MQ socket, destroys contents after sending if destroy param is set to true.int
size()
java.lang.Object[]
toArray()
<T> T[]
toArray(T[] arg0)
java.lang.String
toString()
Returns pretty string representation of multipart message: [ frame0, frame1, ..., frameN ]ZFrame
unwrap()
Pop frame off front of message, caller now owns frame.ZMsg
wrap(ZFrame frame)
Push frame plus empty frame to front of message, before 1st frame.-
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
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Field Detail
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frames
private final java.util.ArrayDeque<ZFrame> frames
Hold internal list of ZFrame objects
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Method Detail
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destroy
public void destroy()
Destructor. Explicitly destroys all ZFrames contains in the ZMsg
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contentSize
public long contentSize()
- Returns:
- total number of bytes contained in all ZFrames in this ZMsg
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addString
public ZMsg addString(java.lang.String str)
Add a String as a new ZFrame to the end of list- Parameters:
str
- String to add to list
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duplicate
public ZMsg duplicate()
Creates copy of this ZMsg. Also duplicates all frame content.- Returns:
- The duplicated ZMsg object, else null if this ZMsg contains an empty frame set
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wrap
public ZMsg wrap(ZFrame frame)
Push frame plus empty frame to front of message, before 1st frame. Message takes ownership of frame, will destroy it when message is sent.- Parameters:
frame
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unwrap
public ZFrame unwrap()
Pop frame off front of message, caller now owns frame. If next frame is empty, pops and destroys that empty frame (e.g. useful when unwrapping ROUTER socket envelopes)- Returns:
- Unwrapped frame
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send
public boolean send(ZMQ.Socket socket)
Send message to 0MQ socket.- Parameters:
socket
- 0MQ socket to send ZMsg on.- Returns:
- true if send is success, false otherwise
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send
public boolean send(ZMQ.Socket socket, boolean destroy)
Send message to 0MQ socket, destroys contents after sending if destroy param is set to true. If the message has no frames, sends nothing but still destroy()s the ZMsg object- Parameters:
socket
- 0MQ socket to send ZMsg on.- Returns:
- true if send is success, false otherwise
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recvMsg
public static ZMsg recvMsg(ZMQ.Socket socket)
Receives message from socket, returns ZMsg object or null if the recv was interrupted. Does a blocking recv, if you want not to block then use the ZLoop class or ZMQ.Poller to check for socket input before receiving or recvMsg with flag ZMQ.DONTWAIT.- Parameters:
socket
-- Returns:
- ZMsg object, null if interrupted
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recvMsg
public static ZMsg recvMsg(ZMQ.Socket socket, boolean wait)
Receives message from socket, returns ZMsg object or null if the recv was interrupted.- Parameters:
socket
-wait
- true to wait for next message, false to do a non-blocking recv.- Returns:
- ZMsg object, null if interrupted
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recvMsg
public static ZMsg recvMsg(ZMQ.Socket socket, int flag)
Receives message from socket, returns ZMsg object or null if the recv was interrupted. Setting the flag to ZMQ.DONTWAIT does a non-blocking recv.- Parameters:
socket
-flag
- see ZMQ constants- Returns:
- ZMsg object, null if interrupted
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recvMsg
public static void recvMsg(ZMQ.Socket socket, int flags, Consumer<ZMsg> handler, Consumer<ZMQException> exceptionHandler)
This API is in DRAFT state and is subject to change at ANY time until declared stable handle incoming message with a handler- Parameters:
socket
-flags
- see ZMQ constantshandler
- handler to handle incoming messageexceptionHandler
- handler to handle exceptions
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recvMsg
public static void recvMsg(ZMQ.Socket socket, int flags, Consumer<ZMsg> handler)
This API is in DRAFT state and is subject to change at ANY time until declared stable handle incoming message with a handler- Parameters:
socket
-flags
- see ZMQ constantshandler
- handler to handle incoming message
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save
public static boolean save(ZMsg msg, java.io.DataOutputStream file)
Save message to an open data output stream. Data saved as: 4 bytes: number of frames For every frame: 4 bytes: byte size of frame data + n bytes: frame byte data- Parameters:
msg
- ZMsg to savefile
- DataOutputStream- Returns:
- True if saved OK, else false
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load
public static ZMsg load(java.io.DataInputStream file)
Load / append a ZMsg from an open DataInputStream- Parameters:
file
- DataInputStream connected to file- Returns:
- ZMsg object
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newStringMsg
public static ZMsg newStringMsg(java.lang.String... strings)
Create a new ZMsg from one or more Strings- Parameters:
strings
- Strings to add as frames.- Returns:
- ZMsg object
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equals
public boolean equals(java.lang.Object o)
- Specified by:
equals
in interfacejava.util.Collection<ZFrame>
- Overrides:
equals
in classjava.lang.Object
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hashCode
public int hashCode()
- Specified by:
hashCode
in interfacejava.util.Collection<ZFrame>
- Overrides:
hashCode
in classjava.lang.Object
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dump
public ZMsg dump(java.lang.Appendable out)
Dump the message in human readable format. This should only be used for debugging and tracing, inefficient in handling large messages.
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dump
public ZMsg dump()
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addFirst
public ZMsg addFirst(java.lang.String stringValue)
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addFirst
public ZMsg addFirst(byte[] data)
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addLast
public ZMsg addLast(java.lang.String stringValue)
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addLast
public ZMsg addLast(byte[] data)
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push
public ZMsg push(java.lang.String str)
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push
public ZMsg push(byte[] data)
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add
public boolean add(java.lang.String stringValue)
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add
public boolean add(byte[] data)
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append
public ZMsg append(java.lang.String stringValue)
Adds a string as a new frame in the message.- Parameters:
stringValue
- the value to add- Returns:
- this
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append
public ZMsg append(byte[] data)
Adds bytes as a new frame in the message.- Parameters:
data
- the value to add- Returns:
- this
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iterator
public java.util.Iterator<ZFrame> iterator()
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addAll
public boolean addAll(java.util.Collection<? extends ZFrame> arg0)
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clear
public void clear()
- Specified by:
clear
in interfacejava.util.Collection<ZFrame>
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containsAll
public boolean containsAll(java.util.Collection<?> arg0)
- Specified by:
containsAll
in interfacejava.util.Collection<ZFrame>
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isEmpty
public boolean isEmpty()
- Specified by:
isEmpty
in interfacejava.util.Collection<ZFrame>
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removeAll
public boolean removeAll(java.util.Collection<?> arg0)
- Specified by:
removeAll
in interfacejava.util.Collection<ZFrame>
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retainAll
public boolean retainAll(java.util.Collection<?> arg0)
- Specified by:
retainAll
in interfacejava.util.Collection<ZFrame>
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toArray
public java.lang.Object[] toArray()
- Specified by:
toArray
in interfacejava.util.Collection<ZFrame>
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toArray
public <T> T[] toArray(T[] arg0)
- Specified by:
toArray
in interfacejava.util.Collection<ZFrame>
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add
public boolean add(ZFrame e)
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addFirst
public void addFirst(ZFrame e)
- Specified by:
addFirst
in interfacejava.util.Deque<ZFrame>
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contains
public boolean contains(java.lang.Object o)
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descendingIterator
public java.util.Iterator<ZFrame> descendingIterator()
- Specified by:
descendingIterator
in interfacejava.util.Deque<ZFrame>
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element
public ZFrame element()
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offer
public boolean offer(ZFrame e)
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offerFirst
public boolean offerFirst(ZFrame e)
- Specified by:
offerFirst
in interfacejava.util.Deque<ZFrame>
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offerLast
public boolean offerLast(ZFrame e)
- Specified by:
offerLast
in interfacejava.util.Deque<ZFrame>
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peek
public ZFrame peek()
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poll
public ZFrame poll()
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popString
public java.lang.String popString()
Pop a ZFrame and return the toString() representation of it.- Returns:
- toString version of pop'ed frame, or null if no frame exists.
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remove
public ZFrame remove()
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remove
public boolean remove(java.lang.Object o)
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removeFirst
public ZFrame removeFirst()
- Specified by:
removeFirst
in interfacejava.util.Deque<ZFrame>
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removeFirstOccurrence
public boolean removeFirstOccurrence(java.lang.Object o)
- Specified by:
removeFirstOccurrence
in interfacejava.util.Deque<ZFrame>
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removeLastOccurrence
public boolean removeLastOccurrence(java.lang.Object o)
- Specified by:
removeLastOccurrence
in interfacejava.util.Deque<ZFrame>
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size
public int size()
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toString
public java.lang.String toString()
Returns pretty string representation of multipart message: [ frame0, frame1, ..., frameN ]- Overrides:
toString
in classjava.lang.Object
- Returns:
- toString version of ZMsg object
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