Package org.zeromq

## Class ZFrame

- java.lang.Object
- - org.zeromq.ZFrame

-     public class ZFrame
      extends Object

  ZFrame The ZFrame class provides methods to send and receive single message frames across 0MQ sockets. A 'frame' corresponds to one underlying zmq_msg_t in the libzmq code. When you read a frame from a socket, the more() method indicates if the frame is part of an unfinished multipart message. The send() method normally destroys the frame, but with the ZFRAME_REUSE flag, you can send the same frame many times. Frames are binary, and this class has no special support for text data. Based on zframe.c in czmq

- - ### Field Summary

    Fields
    Modifier and Type | Field | Description
    --- | --- | ---
    `static int` | `DONTWAIT` |
    `static int` | `MORE` |
    `static int` | `REUSE` |

  - ### Constructor Summary

    Constructors
    Modifier | Constructor | Description
    --- | --- | ---
    `protected` | `ZFrame()` | Class Constructor Creates an empty frame.
    `` | `ZFrame​(byte[] data)` | Class Constructor Copies message data into ZFrame object
    `` | `ZFrame​(String data)` | Class Constructor Copies String into frame data

  - ### Method Summary

    All Methods Static Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `void` | `destroy()` | Destructor.
    `ZFrame` | `duplicate()` | Creates a new frame that duplicates an existing frame
    `boolean` | `equals​(Object o)` |
    `byte[]` | `getData()` |
    `boolean` | `hasData()` | Convenience method to ascertain if this frame contains some message data
    `int` | `hashCode()` |
    `boolean` | `hasMore()` |
    `boolean` | `hasSameData​(ZFrame other)` | Returns true if both frames have byte - for byte identical data
    `void` | `print​(String prefix)` |
    `static ZFrame` | `recvFrame​(ZMQ.Socket socket)` | Receives single frame from socket, returns the received frame object, or null if the recv was interrupted.
    `static ZFrame` | `recvFrame​(ZMQ.Socket socket, int flags)` | Receive a new frame off the socket, Returns newly-allocated frame, or null if there was no input waiting, or if the read was interrupted.
    `void` | `reset​(byte[] data)` | Sets new contents for frame
    `void` | `reset​(String data)` | Sets new contents for frame
    `boolean` | `send​(ZMQ.Socket socket, int flags)` | Method to call org.zeromq.Socket send() method.
    `boolean` | `sendAndDestroy​(ZMQ.Socket socket)` | Sends frame to socket if it contains data.
    `boolean` | `sendAndDestroy​(ZMQ.Socket socket, int flags)` | Sends frame to socket if it contains data.
    `boolean` | `sendAndKeep​(ZMQ.Socket socket)` | Sends frame to socket if it contains any data.
    `boolean` | `sendAndKeep​(ZMQ.Socket socket, int flags)` | Sends frame to socket if it contains any data.
    `int` | `size()` | Returns byte size of frame, if set, else 0
    `boolean` | `streq​(String str)` | String equals.
    `String` | `strhex()` | Returns frame data as a printable hex string
    `String` | `toString()` | Returns a human - readable representation of frame's data

    - ### Methods inherited from class java.lang.Object

      `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

- - ### Field Detail

    - #### MORE

          public static final int MORE

      See Also:
        Constant Field Values

    - #### REUSE

          public static final int REUSE

      See Also:
        Constant Field Values

    - #### DONTWAIT

          public static final int DONTWAIT

      See Also:
        Constant Field Values

  - ### Constructor Detail

    - #### ZFrame

          protected ZFrame()

      Class Constructor Creates an empty frame. (Useful when reading frames from a 0MQ Socket)

    - #### ZFrame

          public ZFrame​(byte[] data)

      Class Constructor Copies message data into ZFrame object
      Parameters:
        `data` - Data to copy into ZFrame object

    - #### ZFrame

          public ZFrame​(String data)

      Class Constructor Copies String into frame data
      Parameters:
        `data` -

  - ### Method Detail

    - #### destroy

          public void destroy()

      Destructor.

    - #### getData

          public byte[] getData()

      Returns:
        the data

    - #### hasMore

          public boolean hasMore()

      Returns:
        More flag, true if last read had MORE message parts to come

    - #### size

          public int size()

      Returns byte size of frame, if set, else 0
      Returns:
        Number of bytes in frame data, else 0

    - #### hasData

          public boolean hasData()

      Convenience method to ascertain if this frame contains some message data
      Returns:
        True if frame contains data

    - #### send

          public boolean send​(ZMQ.Socket socket,
                              int flags)

      Method to call org.zeromq.Socket send() method.
      Parameters:
        `socket` - 0MQ socket to send on
        `flags` - Valid send() method flags, defined in org.zeromq.ZMQ class
      Returns:
        True if success, else False

    - #### sendAndKeep

          public boolean sendAndKeep​(ZMQ.Socket socket,
                                     int flags)

      Sends frame to socket if it contains any data. Frame contents are kept after the send.
      Parameters:
        `socket` - 0MQ socket to send frame
        `flags` - Valid send() method flags, defined in org.zeromq.ZMQ class
      Returns:
        True if success, else False

    - #### sendAndKeep

          public boolean sendAndKeep​(ZMQ.Socket socket)

      Sends frame to socket if it contains any data. Frame contents are kept after the send. Uses default behaviour of Socket.send() method, with no flags set
      Parameters:
        `socket` - 0MQ socket to send frame
      Returns:
        True if success, else False

    - #### sendAndDestroy

          public boolean sendAndDestroy​(ZMQ.Socket socket,
                                        int flags)

      Sends frame to socket if it contains data. Use this method to send a frame and destroy the data after.
      Parameters:
        `socket` - 0MQ socket to send frame
        `flags` - Valid send() method flags, defined in org.zeromq.ZMQ class
      Returns:
        True if success, else False

    - #### sendAndDestroy

          public boolean sendAndDestroy​(ZMQ.Socket socket)

      Sends frame to socket if it contains data. Use this method to send an isolated frame and destroy the data after. Uses default behaviour of Socket.send() method, with no flags set
      Parameters:
        `socket` - 0MQ socket to send frame
      Returns:
        True if success, else False

    - #### duplicate

          public ZFrame duplicate()

      Creates a new frame that duplicates an existing frame
      Returns:
        Duplicate of frame; message contents copied into new byte array

    - #### hasSameData

          public boolean hasSameData​(ZFrame other)

      Returns true if both frames have byte - for byte identical data
      Parameters:
        `other` - The other ZFrame to compare
      Returns:
        True if both ZFrames have same byte-identical data, else false

    - #### reset

          public void reset​(byte[] data)

      Sets new contents for frame
      Parameters:
        `data` - New byte array contents for frame

    - #### reset

          public void reset​(String data)

      Sets new contents for frame
      Parameters:
        `data` - String contents for frame

    - #### strhex

          public String strhex()

      Returns frame data as a printable hex string
      Returns:

    - #### streq

          public boolean streq​(String str)

      String equals. Uses String compareTo for the comparison (lexigraphical)
      Parameters:
        `str` - String to compare with frame data
      Returns:
        True if frame body data matches given string

    - #### equals

          public boolean equals​(Object o)

      Overrides:
        `equals` in class `Object`

    - #### hashCode

          public int hashCode()

      Overrides:
        `hashCode` in class `Object`

    - #### toString

          public String toString()

      Returns a human - readable representation of frame's data
      Overrides:
        `toString` in class `Object`
      Returns:
        A text string or hex-encoded string if data contains any non-printable ASCII characters

    - #### recvFrame

          public static ZFrame recvFrame​(ZMQ.Socket socket)

      Receives single frame from socket, returns the received frame object, or null if the recv was interrupted. Does a blocking recv, if you want to not block then use recvFrame(socket, ZMQ.DONTWAIT);
      Parameters:
        `socket` - Socket to read from
      Returns:
        received frame, else null

    - #### recvFrame

          public static ZFrame recvFrame​(ZMQ.Socket socket,
                                         int flags)

      Receive a new frame off the socket, Returns newly-allocated frame, or null if there was no input waiting, or if the read was interrupted.
      Parameters:
        `socket` - Socket to read from
        `flags` - Pass flags to 0MQ socket.recv call
      Returns:
        received frame, else null

    - #### print

          public void print​(String prefix)