com.rabbitmq.client.impl

Class Frame

java.lang.Object

com.rabbitmq.client.impl.Frame

public class Frame
extends Object

Represents an AMQP wire-protocol frame, with frame type, channel number, and payload bytes. TODO: make state private

Field Summary

Fields

Modifier and Type	Field and Description
int	channel Frame channel number, 0-65535
int	type Frame type code

Constructor Summary

Constructors

Constructor and Description
Frame(int type, int channel) Constructs a frame for output with a type and a channel number and a fresh accumulator waiting for payload.
Frame(int type, int channel, byte[] payload) Constructs a frame for input with a type, a channel number and a payload byte array.

Method Summary

Modifier and Type	Method and Description
static long	arraySize(List<?> values) Computes the AMQP 0-9-1 wire-protocol length of an encoded field-array of type List
static long	arraySize(Object[] values) Computes the AMQP wire-protocol length of an encoded field-array of type Object[]
static Frame	fromBodyFragment(int channelNumber, byte[] body, int offset, int length)
DataInputStream	getInputStream() Public API - retrieves a new DataInputStream streaming over the payload
DataOutputStream	getOutputStream() Public API - retrieves a fresh DataOutputStream streaming into the accumulator
byte[]	getPayload() Public API - retrieves the frame payload
static void	protocolVersionMismatch(DataInputStream is) Private API - A protocol version mismatch is detected by checking the three next bytes if a frame type of (int)'A' is read from an input stream.
static Frame	readFrom(DataInputStream is) Protected API - Factory method to instantiate a Frame by reading an AMQP-wire-protocol frame from the given input stream.
int	size()
static long	tableSize(Map<String,Object> table) Computes the AMQP wire-protocol length of protocol-encoded table entries.
String	toString()
void	writeTo(DataOutputStream os) Public API - writes this Frame to the given DataOutputStream

Methods inherited from class java.lang.Object

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

Field Detail

type

public final int type

Frame type code

channel

public final int channel

Frame channel number, 0-65535

Constructor Detail

Frame

public Frame(int type,
             int channel)

Constructs a frame for output with a type and a channel number and a fresh accumulator waiting for payload.

Frame

public Frame(int type,
             int channel,
             byte[] payload)

Constructs a frame for input with a type, a channel number and a payload byte array.

Method Detail

fromBodyFragment

public static Frame fromBodyFragment(int channelNumber,
                                     byte[] body,
                                     int offset,
                                     int length)
                              throws IOException

Throws:

IOException

readFrom

public static Frame readFrom(DataInputStream is)
                      throws IOException

Protected API - Factory method to instantiate a Frame by reading an AMQP-wire-protocol frame from the given input stream.

Returns:

a new Frame if we read a frame successfully, otherwise null

Throws:

IOException

protocolVersionMismatch

public static void protocolVersionMismatch(DataInputStream is)
                                    throws IOException

Private API - A protocol version mismatch is detected by checking the three next bytes if a frame type of (int)'A' is read from an input stream. If the next three bytes are 'M', 'Q' and 'P', then it's likely the broker is trying to tell us we are speaking the wrong AMQP protocol version.

Throws:

MalformedFrameException - if an AMQP protocol version mismatch is detected

MalformedFrameException - if a corrupt AMQP protocol identifier is read

IOException

writeTo

public void writeTo(DataOutputStream os)
             throws IOException

Public API - writes this Frame to the given DataOutputStream

Throws:

IOException

size

public int size()

getPayload

public byte[] getPayload()

Public API - retrieves the frame payload

getInputStream

public DataInputStream getInputStream()

Public API - retrieves a new DataInputStream streaming over the payload

getOutputStream

public DataOutputStream getOutputStream()

Public API - retrieves a fresh DataOutputStream streaming into the accumulator

toString

public String toString()

Overrides:

toString in class Object

tableSize

public static long tableSize(Map<String,Object> table)
                      throws UnsupportedEncodingException

Computes the AMQP wire-protocol length of protocol-encoded table entries.

Throws:

UnsupportedEncodingException

arraySize

public static long arraySize(List<?> values)
                      throws UnsupportedEncodingException

Computes the AMQP 0-9-1 wire-protocol length of an encoded field-array of type List

Throws:

UnsupportedEncodingException

arraySize

public static long arraySize(Object[] values)
                      throws UnsupportedEncodingException

Computes the AMQP wire-protocol length of an encoded field-array of type Object[]

Throws:

UnsupportedEncodingException