Home » activemq-parent-5.3.1-source-release » org.apache » activemq » command » [javadoc | source]
org.apache.activemq.command
public class: ActiveMQStreamMessage [javadoc | source]
java.lang.Object
   org.apache.activemq.command.BaseCommand
      org.apache.activemq.command.Message
         org.apache.activemq.command.ActiveMQMessage
            org.apache.activemq.command.ActiveMQStreamMessage

All Implemented Interfaces:
    javax.jms.StreamMessage, Message, MarshallAware, MessageReference, Command

A StreamMessage object is used to send a stream of primitive types in the Java programming language. It is filled and read sequentially. It inherits from the Message interface and adds a stream message body. Its methods are based largely on those found in java.io.DataInputStream and java.io.DataOutputStream.

The primitive types can be read or written explicitly using methods for each type. They may also be read or written generically as objects. For instance, a call to StreamMessage.writeInt(6) is equivalent to StreamMessage.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 body 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.

StreamMessage objects support the following conversion table. The marked cases must be supported. The unmarked cases must throw a JMSException. The String-to-primitive conversions may throw a runtime exception if the primitive's valueOf() method does not accept it as a valid String representation of the primitive.

A value written as the row type can be read as the column type.

 | | boolean byte short char int long float double String byte[]
|----------------------------------------------------------------------
|boolean | X X |byte | X X X X X |short | X X X X |char | X X |int | X X X
|long | X X |float | X X X |double | X X |String | X X X X X X X X |byte[] |
X |----------------------------------------------------------------------

Attempting to read a null value as a primitive type must be treated as calling the primitive's corresponding valueOf(String) conversion method with a null value. Since char does not support a String conversion, attempting to read a null value as a char must throw a NullPointerException.

Field Summary
public static final  byte DATA_STRUCTURE_TYPE     
protected transient  DataOutputStream dataOut     
protected transient  ByteArrayOutputStream bytesOut     
protected transient  DataInputStream dataIn     
protected transient  int remainingBytes     
Fields inherited from org.apache.activemq.command.ActiveMQMessage:
DATA_STRUCTURE_TYPE,  acknowledgeCallback
Fields inherited from org.apache.activemq.command.Message:
DEFAULT_MINIMUM_MESSAGE_SIZE,  messageId,  originalDestination,  originalTransactionId,  producerId,  destination,  transactionId,  expiration,  timestamp,  arrival,  brokerInTime,  brokerOutTime,  correlationId,  replyTo,  persistent,  type,  priority,  groupID,  groupSequence,  targetConsumerId,  compressed,  userID,  content,  marshalledProperties,  dataStructure,  redeliveryCounter,  size,  properties,  readOnlyProperties,  readOnlyBody,  recievedByDFBridge,  droppable
Fields inherited from org.apache.activemq.command.BaseCommand:
commandId,  responseRequired
Method from org.apache.activemq.command.ActiveMQStreamMessage Summary:
checkWriteOnlyBody,   clearBody,   copy,   getDataStructureType,   getJMSXMimeType,   onSend,   readBoolean,   readByte,   readBytes,   readChar,   readDouble,   readFloat,   readInt,   readLong,   readObject,   readShort,   readString,   reset,   toString,   writeBoolean,   writeByte,   writeBytes,   writeBytes,   writeChar,   writeDouble,   writeFloat,   writeInt,   writeLong,   writeObject,   writeShort,   writeString
Methods from org.apache.activemq.command.ActiveMQMessage:
acknowledge,   checkReadOnlyBody,   checkValidObject,   clearBody,   clearProperties,   copy,   copy,   decodeString,   encodeString,   equals,   getAcknowledgeCallback,   getBooleanProperty,   getByteProperty,   getDataStructureType,   getDoubleProperty,   getFloatProperty,   getIntProperty,   getJMSCorrelationID,   getJMSCorrelationIDAsBytes,   getJMSDeliveryMode,   getJMSDestination,   getJMSExpiration,   getJMSMessageID,   getJMSPriority,   getJMSRedelivered,   getJMSReplyTo,   getJMSTimestamp,   getJMSType,   getJMSXMimeType,   getLongProperty,   getObjectProperty,   getPropertyNames,   getShortProperty,   getStringProperty,   hashCode,   onSend,   propertyExists,   setAcknowledgeCallback,   setBooleanProperty,   setBooleanProperty,   setByteProperty,   setDoubleProperty,   setFloatProperty,   setIntProperty,   setJMSCorrelationID,   setJMSCorrelationIDAsBytes,   setJMSDeliveryMode,   setJMSDestination,   setJMSExpiration,   setJMSMessageID,   setJMSMessageID,   setJMSPriority,   setJMSRedelivered,   setJMSReplyTo,   setJMSTimestamp,   setJMSType,   setLongProperty,   setObjectProperty,   setObjectProperty,   setProperties,   setShortProperty,   setStringProperty,   visit
Methods from org.apache.activemq.command.Message:
afterMarshall,   afterUnmarshall,   beforeMarshall,   beforeUnmarshall,   clearBody,   clearProperties,   copy,   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,   isExpired,   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,   toString
Methods from org.apache.activemq.command.BaseCommand:
copy,   getCommandId,   getFrom,   getTo,   isBrokerInfo,   isMarshallAware,   isMessage,   isMessageAck,   isMessageDispatch,   isMessageDispatchNotification,   isResponse,   isResponseRequired,   isShutdownInfo,   isWireFormatInfo,   setCommandId,   setFrom,   setResponseRequired,   setTo,   toString,   toString
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from org.apache.activemq.command.ActiveMQStreamMessage Detail:
 protected  void checkWriteOnlyBody() throws MessageNotReadableException 
 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.

 public Message copy() 
 public byte getDataStructureType() 
 public String getJMSXMimeType() 
 public  void onSend() throws JMSException 
 public boolean readBoolean() throws JMSException 
    Reads a boolean from the stream message.
 public byte readByte() throws JMSException 
    Reads a byte value from the stream message.
 public int readBytes(byte[] value) throws JMSException 
    Reads a byte array field from the stream message into the specified byte[] object (the read buffer).

    To read the field value, readBytes should be successively called until it returns a value less than the length of the read buffer. The value of the bytes in the buffer following the last byte read is undefined.

    If readBytes returns a value equal to the length of the buffer, a subsequent readBytes call must be made. If there are no more bytes to be read, this call returns -1.

    If the byte array field value is null, readBytes returns -1.

    If the byte array field value is empty, readBytes returns 0.

    Once the first readBytes call on a byte[] field value has been made, the full value of the field must be read before it is valid to read the next field. An attempt to read the next field before that has been done will throw a MessageFormatException.

    To read the byte field value into a new byte[] object, use the readObject method.

 public char readChar() throws JMSException 
    Reads a Unicode character value from the stream message.
 public double readDouble() throws JMSException 
    Reads a double from the stream message.
 public float readFloat() throws JMSException 
    Reads a float from the stream message.
 public int readInt() throws JMSException 
    Reads a 32-bit integer from the stream message.
 public long readLong() throws JMSException 
    Reads a 64-bit integer from the stream message.
 public Object readObject() throws JMSException 
    Reads an object from the stream message.

    This method can be used to return, in objectified format, an object in the Java programming language ("Java object") that has been written to the stream with the equivalent writeObject method call, or its equivalent primitive writetype method.

    Note that byte values are returned as byte[], not Byte[].

    An attempt to call readObject to read a byte field value into a new byte[] object before the full value of the byte field has been read will throw a MessageFormatException.

 public short readShort() throws JMSException 
    Reads a 16-bit integer from the stream message.
 public String readString() throws JMSException 
    Reads a String from the stream message.
 public  void reset() throws JMSException 
    Puts the message body in read-only mode and repositions the stream of bytes to the beginning.
 public String toString() 
 public  void writeBoolean(boolean value) throws JMSException 
    Writes a boolean to the stream message. The value true is written as the value (byte)1; the value false is written as the value (byte)0.
 public  void writeByte(byte value) throws JMSException 
    Writes a byte to the stream message.
 public  void writeBytes(byte[] value) throws JMSException 
    Writes a byte array field to the stream message.

    The byte array value is written to the message as a byte array field. Consecutively written byte array fields are treated as two distinct fields when the fields are read.

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

    The a portion of the byte array value is written to the message as a byte array field. Consecutively written byte array fields are treated as two distinct fields when the fields are read.

 public  void writeChar(char value) throws JMSException 
    Writes a char to the stream message.
 public  void writeDouble(double value) throws JMSException 
    Writes a double to the stream message.
 public  void writeFloat(float value) throws JMSException 
    Writes a float to the stream message.
 public  void writeInt(int value) throws JMSException 
    Writes an int to the stream message.
 public  void writeLong(long value) throws JMSException 
    Writes a long to the stream message.
 public  void writeObject(Object value) throws JMSException 
    Writes an object to the stream message.

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

 public  void writeShort(short value) throws JMSException 
    Writes a short to the stream message.
 public  void writeString(String value) throws JMSException 
    Writes a String to the stream message.