Package com.rabbitmq.client.impl

Class AMQCommand

  • All Implemented Interfaces:
    Command
    public class AMQCommand
extends java.lang.Object
implements Command
    AMQP 0-9-1-specific implementation of Command which accumulates method, header and body from a series of frames, unless these are supplied at construction time.

    Concurrency

    This class is thread-safe.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private CommandAssembler assembler
      The assembler for this command - synchronised on - contains all the state
      private java.util.concurrent.locks.Lock assemblerLock  
      static int EMPTY_FRAME_SIZE
      EMPTY_FRAME_SIZE = 8 = 1 + 2 + 4 + 1 1 byte of frame type 2 bytes of channel number 4 bytes of frame payload length 1 byte of payload trailer FRAME_END byte See checkEmptyFrameSize(), an assertion checked at startup.

    • Constructor Summary

      Constructors 
      Constructor Description
      AMQCommand()
      Construct a command ready to fill in by reading frames
      AMQCommand​(int maxBodyLength)  
      AMQCommand​(Method method)
      Construct a command with just a method, and without header or body.
      AMQCommand​(Method method, AMQContentHeader contentHeader, byte[] body)
      Construct a command with a specified method, header and body.
      AMQCommand​(Method method, AMQContentHeader contentHeader, byte[] body, int maxBodyLength)
      Construct a command with a specified method, header and body.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      private static void checkEmptyFrameSize()
      Since we're using a pre-computed value for EMPTY_FRAME_SIZE we check this is actually correct when run against the framing code in Frame.
      static void checkPreconditions()
      Called to check internal code assumptions.
      private static java.lang.StringBuilder contentBodyStringBuilder​(byte[] body, boolean suppressBody)  
      byte[] getContentBody()
      Public API - Retrieves the body byte array that travelled as part of this Command, if any.
      AMQContentHeader getContentHeader()
      Public API - Retrieves the ContentHeader subclass instance held as part of this Command, if any.
      Method getMethod()
      Public API - Retrieves the Method held within this Command.
      boolean handleFrame​(Frame f)  
      java.lang.String toString()  
      java.lang.String toString​(boolean suppressBody)  
      void transmit​(AMQChannel channel)
      Sends this command down the named channel on the channel's connection, possibly in multiple frames.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • EMPTY_FRAME_SIZE

        public static final int EMPTY_FRAME_SIZE
        EMPTY_FRAME_SIZE = 8 = 1 + 2 + 4 + 1
        • 1 byte of frame type
        • 2 bytes of channel number
        • 4 bytes of frame payload length
        • 1 byte of payload trailer FRAME_END byte
        See checkEmptyFrameSize(), an assertion checked at startup.
        See Also:
        Constant Field Values

      • assembler

        private final CommandAssembler assembler
        The assembler for this command - synchronised on - contains all the state

      • assemblerLock

        private final java.util.concurrent.locks.Lock assemblerLock

    • Constructor Detail

      • AMQCommand

        AMQCommand​(int maxBodyLength)

      • AMQCommand

        public AMQCommand()
        Construct a command ready to fill in by reading frames

      • AMQCommand

        public AMQCommand​(Method method)
        Construct a command with just a method, and without header or body.
        Parameters:
        method - the wrapped method

      • AMQCommand

        public AMQCommand​(Method method,
                  AMQContentHeader contentHeader,
                  byte[] body)
        Construct a command with a specified method, header and body.
        Parameters:
        method - the wrapped method
        contentHeader - the wrapped content header
        body - the message body data

      • AMQCommand

        public AMQCommand​(Method method,
                  AMQContentHeader contentHeader,
                  byte[] body,
                  int maxBodyLength)
        Construct a command with a specified method, header and body.
        Parameters:
        method - the wrapped method
        contentHeader - the wrapped content header
        body - the message body data
        maxBodyLength - the maximum size for an inbound message body

    • Method Detail

      • getMethod

        public Method getMethod()
        Public API - Retrieves the Method held within this Command. Downcast to concrete (implementation-specific!) subclasses as necessary.
        Specified by:
        getMethod in interface Command
        Returns:
        the command's method.

      • getContentHeader

        public AMQContentHeader getContentHeader()
        Public API - Retrieves the ContentHeader subclass instance held as part of this Command, if any. Downcast to one of the inner classes of AMQP, for instance AMQP.BasicProperties, as appropriate.
        Specified by:
        getContentHeader in interface Command
        Returns:
        the Command's ContentHeader, or null if none

      • getContentBody

        public byte[] getContentBody()
        Public API - Retrieves the body byte array that travelled as part of this Command, if any.
        Specified by:
        getContentBody in interface Command
        Returns:
        the Command's content body, or null if none

      • handleFrame

        public boolean handleFrame​(Frame f)
                    throws java.io.IOException
        Throws:
        java.io.IOException

      • transmit

        public void transmit​(AMQChannel channel)
              throws java.io.IOException
        Sends this command down the named channel on the channel's connection, possibly in multiple frames.
        Parameters:
        channel - the channel on which to transmit the command
        Throws:
        java.io.IOException - if an error is encountered

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • toString

        public java.lang.String toString​(boolean suppressBody)

      • contentBodyStringBuilder

        private static java.lang.StringBuilder contentBodyStringBuilder​(byte[] body,
                                                                boolean suppressBody)

      • checkPreconditions

        public static void checkPreconditions()
        Called to check internal code assumptions.

      • checkEmptyFrameSize

        private static void checkEmptyFrameSize()
        Since we're using a pre-computed value for EMPTY_FRAME_SIZE we check this is actually correct when run against the framing code in Frame.