org.apache.activemq.command
Class ActiveMQBytesMessage

java.lang.Object
  extended by org.apache.activemq.command.BaseCommand
      extended by org.apache.activemq.command.Message
          extended by org.apache.activemq.command.ActiveMQMessage
              extended by org.apache.activemq.command.ActiveMQBytesMessage
All Implemented Interfaces:
BytesMessage, Message, MessageReference, Command, DataStructure, MarshallAware

public class ActiveMQBytesMessage
extends ActiveMQMessage
implements BytesMessage

A BytesMessage object is used to send a message containing a stream of uninterpreted bytes. It inherits from the Message interface and adds a bytes message body. The receiver of the message supplies the interpretation of the bytes.

The BytesMessage methods are based largely on those found in java.io.DataInputStream and java.io.DataOutputStream.

This message type is for client encoding of existing message formats. If possible, one of the other self-defining message types should be used instead.

Although the JMS API allows the use of message properties with byte messages, they are typically not used, since the inclusion of properties may affect the format.

The primitive types can be written explicitly using methods for each type. They may also be written generically as objects. For instance, a call to BytesMessage.writeInt(6) is equivalent to BytesMessage.writeObject(new Integer(6)). Both forms are provided, because the explicit form is convenient for static programming, and the object form is needed when types are not known at compile time.

When the message is first created, and when clearBody is called, the body of the message is in write-only mode. After the first call to reset has been made, the message body is in read-only mode. After a message has been sent, the client that sent it can retain and modify it without affecting the message that has been sent. The same message object can be sent multiple times. When a message has been received, the provider has called reset so that the message body is in read-only mode for the client.

If clearBody is called on a message in read-only mode, the message body is cleared and the message is in write-only mode.

If a client attempts to read a message in write-only mode, a MessageNotReadableException is thrown.

If a client attempts to write a message in read-only mode, a MessageNotWriteableException is thrown.

See Also:
Session.createBytesMessage(), MapMessage, Message, ObjectMessage, StreamMessage, TextMessage

Field Summary
protected  ByteArrayOutputStream bytesOut
           
static byte DATA_STRUCTURE_TYPE
           
protected  DataInputStream dataIn
           
protected  DataOutputStream dataOut
           
protected  int length
           
 
Fields inherited from class org.apache.activemq.command.ActiveMQMessage
acknowledgeCallback
 
Fields inherited from class org.apache.activemq.command.Message
arrival, brokerInTime, brokerOutTime, compressed, content, correlationId, dataStructure, DEFAULT_MINIMUM_MESSAGE_SIZE, destination, droppable, expiration, groupID, groupSequence, marshalledProperties, messageId, originalDestination, originalTransactionId, persistent, priority, producerId, properties, readOnlyBody, readOnlyProperties, recievedByDFBridge, redeliveryCounter, replyTo, size, targetConsumerId, timestamp, transactionId, type, userID
 
Fields inherited from class org.apache.activemq.command.BaseCommand
commandId, responseRequired
 
Fields inherited from interface javax.jms.Message
DEFAULT_DELIVERY_MODE, DEFAULT_PRIORITY, DEFAULT_TIME_TO_LIVE
 
Constructor Summary
ActiveMQBytesMessage()
           
 
Method Summary
protected  void checkWriteOnlyBody()
           
 void clearBody()
          Clears out the message body.
 Message copy()
           
 long getBodyLength()
          Gets the number of bytes of the message body when the message is in read-only mode.
 byte getDataStructureType()
           
 String getJMSXMimeType()
          Returns the MIME type of this mesage.
 void onSend()
          Send operation event listener.
 boolean readBoolean()
          Reads a boolean from the bytes message stream.
 byte readByte()
          Reads a signed 8-bit value from the bytes message stream.
 int readBytes(byte[] value)
          Reads a byte array from the bytes message stream.
 int readBytes(byte[] value, int length)
          Reads a portion of the bytes message stream.
 char readChar()
          Reads a Unicode character value from the bytes message stream.
 double readDouble()
          Reads a double from the bytes message stream.
 float readFloat()
          Reads a float from the bytes message stream.
 int readInt()
          Reads a signed 32-bit integer from the bytes message stream.
 long readLong()
          Reads a signed 64-bit integer from the bytes message stream.
 short readShort()
          Reads a signed 16-bit number from the bytes message stream.
 int readUnsignedByte()
          Reads an unsigned 8-bit number from the bytes message stream.
 int readUnsignedShort()
          Reads an unsigned 16-bit number from the bytes message stream.
 String readUTF()
          Reads a string that has been encoded using a modified UTF-8 format from the bytes message stream.
 void reset()
          Puts the message body in read-only mode and repositions the stream of bytes to the beginning.
 void setObjectProperty(String name, Object value)
           
 String toString()
           
 void writeBoolean(boolean value)
          Writes a boolean to the bytes message stream as a 1-byte value.
 void writeByte(byte value)
          Writes a byte to the bytes message stream as a 1-byte value.
 void writeBytes(byte[] value)
          Writes a byte array to the bytes message stream.
 void writeBytes(byte[] value, int offset, int length)
          Writes a portion of a byte array to the bytes message stream.
 void writeChar(char value)
          Writes a char to the bytes message stream as a 2-byte value, high byte first.
 void writeDouble(double value)
          Converts the double argument to a long using the doubleToLongBits method in class Double, and then writes that long value to the bytes message stream as an 8-byte quantity, high byte first.
 void writeFloat(float value)
          Converts the float argument to an int using the floatToIntBits method in class Float, and then writes that int value to the bytes message stream as a 4-byte quantity, high byte first.
 void writeInt(int value)
          Writes an int to the bytes message stream as four bytes, high byte first.
 void writeLong(long value)
          Writes a long to the bytes message stream as eight bytes, high byte first.
 void writeObject(Object value)
          Writes an object to the bytes message stream.
 void writeShort(short value)
          Writes a short to the bytes message stream as two bytes, high byte first.
 void writeUTF(String value)
          Writes a string to the bytes message stream using UTF-8 encoding in a machine-independent manner.
 
Methods inherited from class org.apache.activemq.command.ActiveMQMessage
acknowledge, checkReadOnlyBody, checkValidObject, clearProperties, copy, decodeString, encodeString, equals, getAcknowledgeCallback, getBooleanProperty, getByteProperty, getDoubleProperty, getFloatProperty, getIntProperty, getJMSCorrelationID, getJMSCorrelationIDAsBytes, getJMSDeliveryMode, getJMSDestination, getJMSExpiration, getJMSMessageID, getJMSPriority, getJMSRedelivered, getJMSReplyTo, getJMSTimestamp, getJMSType, getLongProperty, getObjectProperty, getPropertyNames, getShortProperty, getStringProperty, hashCode, isExpired, propertyExists, setAcknowledgeCallback, setBooleanProperty, setBooleanProperty, setByteProperty, setDoubleProperty, setFloatProperty, setIntProperty, setJMSCorrelationID, setJMSCorrelationIDAsBytes, setJMSDeliveryMode, setJMSDestination, setJMSExpiration, setJMSMessageID, setJMSMessageID, setJMSPriority, setJMSRedelivered, setJMSReplyTo, setJMSTimestamp, setJMSType, setLongProperty, setObjectProperty, setProperties, setShortProperty, setStringProperty, visit
 
Methods inherited from class org.apache.activemq.command.Message
afterMarshall, afterUnmarshall, beforeMarshall, beforeUnmarshall, copy, decrementReferenceCount, getArrival, getBrokerInTime, getBrokerOutTime, getBrokerPath, getCluster, getConnection, getContent, getCorrelationId, getDataStructure, getDestination, getExpiration, getGroupID, getGroupSequence, getMarshalledProperties, getMemoryUsage, getMessage, getMessageHardRef, getMessageId, getMinimumMessageSize, getOriginalDestination, getOriginalTransactionId, getPriority, getProducerId, getProperties, getProperty, getRedeliveryCounter, getReferenceCount, getRegionDestination, getReplyTo, getSize, getTargetConsumerId, getTimestamp, getTransactionId, getType, getUserID, incrementRedeliveryCounter, incrementReferenceCount, isAdvisory, isCompressed, isDroppable, isDropped, isInTransaction, isMarshallAware, isMessage, isPersistent, isReadOnlyBody, isReadOnlyProperties, isRecievedByDFBridge, isRedelivered, lazyCreateProperties, onMessageRolledBack, setArrival, setBrokerInTime, setBrokerOutTime, setBrokerPath, setCluster, setCompressed, setConnection, setContent, setCorrelationId, setDataStructure, setDestination, setDroppable, setExpiration, setGroupID, setGroupSequence, setMarshalledProperties, setMemoryUsage, setMessageId, setOriginalDestination, setOriginalTransactionId, setPersistent, setPriority, setProducerId, setProperty, setReadOnlyBody, setReadOnlyProperties, setRecievedByDFBridge, setRedelivered, setRedeliveryCounter, setRegionDestination, setReplyTo, setTargetConsumerId, setTimestamp, setTransactionId, setType, setUserID, toString
 
Methods inherited from class org.apache.activemq.command.BaseCommand
copy, getCommandId, getFrom, getTo, isBrokerInfo, isMessageAck, isMessageDispatch, isMessageDispatchNotification, isResponse, isResponseRequired, isShutdownInfo, isWireFormatInfo, setCommandId, setFrom, setResponseRequired, setTo
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface javax.jms.Message
acknowledge, clearProperties, getBooleanProperty, getByteProperty, getDoubleProperty, getFloatProperty, getIntProperty, getJMSCorrelationID, getJMSCorrelationIDAsBytes, getJMSDeliveryMode, getJMSDestination, getJMSExpiration, getJMSMessageID, getJMSPriority, getJMSRedelivered, getJMSReplyTo, getJMSTimestamp, getJMSType, getLongProperty, getObjectProperty, getPropertyNames, getShortProperty, getStringProperty, propertyExists, setBooleanProperty, setByteProperty, setDoubleProperty, setFloatProperty, setIntProperty, setJMSCorrelationID, setJMSCorrelationIDAsBytes, setJMSDeliveryMode, setJMSDestination, setJMSExpiration, setJMSMessageID, setJMSPriority, setJMSRedelivered, setJMSReplyTo, setJMSTimestamp, setJMSType, setLongProperty, setShortProperty, setStringProperty
 

Field Detail

DATA_STRUCTURE_TYPE

public static final byte DATA_STRUCTURE_TYPE
See Also:
Constant Field Values

dataOut

protected transient DataOutputStream dataOut

bytesOut

protected transient ByteArrayOutputStream bytesOut

dataIn

protected transient DataInputStream dataIn

length

protected transient int length
Constructor Detail

ActiveMQBytesMessage

public ActiveMQBytesMessage()
Method Detail

copy

public Message copy()
Overrides:
copy in class ActiveMQMessage

onSend

public void onSend()
            throws JMSException
Description copied from class: ActiveMQMessage
Send operation event listener. Used to get the message ready to be sent.

Overrides:
onSend in class ActiveMQMessage
Throws:
JMSException

getDataStructureType

public byte getDataStructureType()
Specified by:
getDataStructureType in interface DataStructure
Overrides:
getDataStructureType in class ActiveMQMessage
Returns:
The type of the data structure

getJMSXMimeType

public String getJMSXMimeType()
Description copied from interface: Message
Returns the MIME type of this mesage. This can be used in selectors to filter on the MIME types of the different JMS messages, or in the case of BlobMessage it allows you to create a selector on the MIME type of the BLOB body

Overrides:
getJMSXMimeType in class ActiveMQMessage

clearBody

public void clearBody()
               throws JMSException
Clears out the message body. Clearing a message's body does not clear its header values or property entries.

If this message body was read-only, calling this method leaves the message body in the same state as an empty body in a newly created message.

Specified by:
clearBody in interface Message
Overrides:
clearBody in class ActiveMQMessage
Throws:
JMSException - if the JMS provider fails to clear the message body due to some internal error.

getBodyLength

public long getBodyLength()
                   throws JMSException
Gets the number of bytes of the message body when the message is in read-only mode. The value returned can be used to allocate a byte array. The value returned is the entire length of the message body, regardless of where the pointer for reading the message is currently located.

Specified by:
getBodyLength in interface BytesMessage
Returns:
number of bytes in the message
Throws:
JMSException - if the JMS provider fails to read the message due to some internal error.
MessageNotReadableException - if the message is in write-only mode.
Since:
1.1

readBoolean

public boolean readBoolean()
                    throws JMSException
Reads a boolean from the bytes message stream.

Specified by:
readBoolean in interface BytesMessage
Returns:
the boolean value read
Throws:
JMSException - if the JMS provider fails to read the message due to some internal error.
MessageEOFException - if unexpected end of bytes stream has been reached.
MessageNotReadableException - if the message is in write-only mode.

readByte

public byte readByte()
              throws JMSException
Reads a signed 8-bit value from the bytes message stream.

Specified by:
readByte in interface BytesMessage
Returns:
the next byte from the bytes message stream as a signed 8-bit byte
Throws:
JMSException - if the JMS provider fails to read the message due to some internal error.
MessageEOFException - if unexpected end of bytes stream has been reached.
MessageNotReadableException - if the message is in write-only mode.

readUnsignedByte

public int readUnsignedByte()
                     throws JMSException
Reads an unsigned 8-bit number from the bytes message stream.

Specified by:
readUnsignedByte in interface BytesMessage
Returns:
the next byte from the bytes message stream, interpreted as an unsigned 8-bit number
Throws:
JMSException - if the JMS provider fails to read the message due to some internal error.
MessageEOFException - if unexpected end of bytes stream has been reached.
MessageNotReadableException - if the message is in write-only mode.

readShort

public short readShort()
                throws JMSException
Reads a signed 16-bit number from the bytes message stream.

Specified by:
readShort in interface BytesMessage
Returns:
the next two bytes from the bytes message stream, interpreted as a signed 16-bit number
Throws:
JMSException - if the JMS provider fails to read the message due to some internal error.
MessageEOFException - if unexpected end of bytes stream has been reached.
MessageNotReadableException - if the message is in write-only mode.

readUnsignedShort

public int readUnsignedShort()
                      throws JMSException
Reads an unsigned 16-bit number from the bytes message stream.

Specified by:
readUnsignedShort in interface BytesMessage
Returns:
the next two bytes from the bytes message stream, interpreted as an unsigned 16-bit integer
Throws:
JMSException - if the JMS provider fails to read the message due to some internal error.
MessageEOFException - if unexpected end of bytes stream has been reached.
MessageNotReadableException - if the message is in write-only mode.

readChar

public char readChar()
              throws JMSException
Reads a Unicode character value from the bytes message stream.

Specified by:
readChar in interface BytesMessage
Returns:
the next two bytes from the bytes message stream as a Unicode character
Throws:
JMSException - if the JMS provider fails to read the message due to some internal error.
MessageEOFException - if unexpected end of bytes stream has been reached.
MessageNotReadableException - if the message is in write-only mode.

readInt

public int readInt()
            throws JMSException
Reads a signed 32-bit integer from the bytes message stream.

Specified by:
readInt in interface BytesMessage
Returns:
the next four bytes from the bytes message stream, interpreted as an int
Throws:
JMSException - if the JMS provider fails to read the message due to some internal error.
MessageEOFException - if unexpected end of bytes stream has been reached.
MessageNotReadableException - if the message is in write-only mode.

readLong

public long readLong()
              throws JMSException
Reads a signed 64-bit integer from the bytes message stream.

Specified by:
readLong in interface BytesMessage
Returns:
the next eight bytes from the bytes message stream, interpreted as a long
Throws:
JMSException - if the JMS provider fails to read the message due to some internal error.
MessageEOFException - if unexpected end of bytes stream has been reached.
MessageNotReadableException - if the message is in write-only mode.

readFloat

public float readFloat()
                throws JMSException
Reads a float from the bytes message stream.

Specified by:
readFloat in interface BytesMessage
Returns:
the next four bytes from the bytes message stream, interpreted as a float
Throws:
JMSException - if the JMS provider fails to read the message due to some internal error.
MessageEOFException - if unexpected end of bytes stream has been reached.
MessageNotReadableException - if the message is in write-only mode.

readDouble

public double readDouble()
                  throws JMSException
Reads a double from the bytes message stream.

Specified by:
readDouble in interface BytesMessage
Returns:
the next eight bytes from the bytes message stream, interpreted as a double
Throws:
JMSException - if the JMS provider fails to read the message due to some internal error.
MessageEOFException - if unexpected end of bytes stream has been reached.
MessageNotReadableException - if the message is in write-only mode.

readUTF

public String readUTF()
               throws JMSException
Reads a string that has been encoded using a modified UTF-8 format from the bytes message stream.

For more information on the UTF-8 format, see "File System Safe UCS Transformation Format (FSS_UTF)", X/Open Preliminary Specification, X/Open Company Ltd., Document Number: P316. This information also appears in ISO/IEC 10646, Annex P.

Specified by:
readUTF in interface BytesMessage
Returns:
a Unicode string from the bytes message stream
Throws:
JMSException - if the JMS provider fails to read the message due to some internal error.
MessageEOFException - if unexpected end of bytes stream has been reached.
MessageNotReadableException - if the message is in write-only mode.

readBytes

public int readBytes(byte[] value)
              throws JMSException
Reads a byte array from the bytes message stream.

If the length of array value is less than the number of bytes remaining to be read from the stream, the array should be filled. A subsequent call reads the next increment, and so on.

If the number of bytes remaining in the stream is less than the length of array value, the bytes should be read into the array. The return value of the total number of bytes read will be less than the length of the array, indicating that there are no more bytes left to be read from the stream. The next read of the stream returns -1.

Specified by:
readBytes in interface BytesMessage
Parameters:
value - the buffer into which the data is read
Returns:
the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached
Throws:
JMSException - if the JMS provider fails to read the message due to some internal error.
MessageNotReadableException - if the message is in write-only mode.

readBytes

public int readBytes(byte[] value,
                     int length)
              throws JMSException
Reads a portion of the bytes message stream.

If the length of array value is less than the number of bytes remaining to be read from the stream, the array should be filled. A subsequent call reads the next increment, and so on.

If the number of bytes remaining in the stream is less than the length of array value, the bytes should be read into the array. The return value of the total number of bytes read will be less than the length of the array, indicating that there are no more bytes left to be read from the stream. The next read of the stream returns -1.

If length is negative, or length is greater than the length of the array value, then an IndexOutOfBoundsException is thrown. No bytes will be read from the stream for this exception case.

Specified by:
readBytes in interface BytesMessage
Parameters:
value - the buffer into which the data is read
length - the number of bytes to read; must be less than or equal to value.length
Returns:
the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached
Throws:
JMSException - if the JMS provider fails to read the message due to some internal error.
MessageNotReadableException - if the message is in write-only mode.

writeBoolean

public void writeBoolean(boolean value)
                  throws JMSException
Writes a boolean to the bytes message stream as a 1-byte value. The value true is written as the value (byte)1; the value false is written as the value (byte)0.

Specified by:
writeBoolean in interface BytesMessage
Parameters:
value - the boolean value to be written
Throws:
JMSException - if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException - if the message is in read-only mode.

writeByte

public void writeByte(byte value)
               throws JMSException
Writes a byte to the bytes message stream as a 1-byte value.

Specified by:
writeByte in interface BytesMessage
Parameters:
value - the byte value to be written
Throws:
JMSException - if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException - if the message is in read-only mode.

writeShort

public void writeShort(short value)
                throws JMSException
Writes a short to the bytes message stream as two bytes, high byte first.

Specified by:
writeShort in interface BytesMessage
Parameters:
value - the short to be written
Throws:
JMSException - if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException - if the message is in read-only mode.

writeChar

public void writeChar(char value)
               throws JMSException
Writes a char to the bytes message stream as a 2-byte value, high byte first.

Specified by:
writeChar in interface BytesMessage
Parameters:
value - the char value to be written
Throws:
JMSException - if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException - if the message is in read-only mode.

writeInt

public void writeInt(int value)
              throws JMSException
Writes an int to the bytes message stream as four bytes, high byte first.

Specified by:
writeInt in interface BytesMessage
Parameters:
value - the int to be written
Throws:
JMSException - if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException - if the message is in read-only mode.

writeLong

public void writeLong(long value)
               throws JMSException
Writes a long to the bytes message stream as eight bytes, high byte first.

Specified by:
writeLong in interface BytesMessage
Parameters:
value - the long to be written
Throws:
JMSException - if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException - if the message is in read-only mode.

writeFloat

public void writeFloat(float value)
                throws JMSException
Converts the float argument to an int using the floatToIntBits method in class Float, and then writes that int value to the bytes message stream as a 4-byte quantity, high byte first.

Specified by:
writeFloat in interface BytesMessage
Parameters:
value - the float value to be written
Throws:
JMSException - if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException - if the message is in read-only mode.

writeDouble

public void writeDouble(double value)
                 throws JMSException
Converts the double argument to a long using the doubleToLongBits method in class Double, and then writes that long value to the bytes message stream as an 8-byte quantity, high byte first.

Specified by:
writeDouble in interface BytesMessage
Parameters:
value - the double value to be written
Throws:
JMSException - if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException - if the message is in read-only mode.

writeUTF

public void writeUTF(String value)
              throws JMSException
Writes a string to the bytes message stream using UTF-8 encoding in a machine-independent manner.

For more information on the UTF-8 format, see "File System Safe UCS Transformation Format (FSS_UTF)", X/Open Preliminary Specification, X/Open Company Ltd., Document Number: P316. This information also appears in ISO/IEC 10646, Annex P.

Specified by:
writeUTF in interface BytesMessage
Parameters:
value - the String value to be written
Throws:
JMSException - if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException - if the message is in read-only mode.

writeBytes

public void writeBytes(byte[] value)
                throws JMSException
Writes a byte array to the bytes message stream.

Specified by:
writeBytes in interface BytesMessage
Parameters:
value - the byte array to be written
Throws:
JMSException - if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException - if the message is in read-only mode.

writeBytes

public void writeBytes(byte[] value,
                       int offset,
                       int length)
                throws JMSException
Writes a portion of a byte array to the bytes message stream.

Specified by:
writeBytes in interface BytesMessage
Parameters:
value - the byte array value to be written
offset - the initial offset within the byte array
length - the number of bytes to use
Throws:
JMSException - if the JMS provider fails to write the message due to some internal error.
MessageNotWriteableException - if the message is in read-only mode.

writeObject

public void writeObject(Object value)
                 throws JMSException
Writes an object to the bytes message stream.

This method works only for the objectified primitive object types (Integer,Double, Long  ...), String objects, and byte arrays.

Specified by:
writeObject in interface BytesMessage
Parameters:
value - the object in the Java programming language ("Java object") to be written; it must not be null
Throws:
JMSException - if the JMS provider fails to write the message due to some internal error.
MessageFormatException - if the object is of an invalid type.
MessageNotWriteableException - if the message is in read-only mode.
NullPointerException - if the parameter value is null.

reset

public void reset()
           throws JMSException
Puts the message body in read-only mode and repositions the stream of bytes to the beginning.

Specified by:
reset in interface BytesMessage
Throws:
JMSException - if an internal error occurs

checkWriteOnlyBody

protected void checkWriteOnlyBody()
                           throws MessageNotReadableException
Throws:
MessageNotReadableException

setObjectProperty

public void setObjectProperty(String name,
                              Object value)
                       throws JMSException
Specified by:
setObjectProperty in interface Message
Overrides:
setObjectProperty in class ActiveMQMessage
Throws:
JMSException

toString

public String toString()
Overrides:
toString in class Message


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