javax.jms
Interface StreamMessage

public interface StreamMessage

extends Message

A StreamMessage is used to send a stream of Java primitives. It is filled and read sequentially. It inherits from Message and adds a stream message body. It's 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. When a message has been sent, by definition, the provider calls reset in order to read it's content, and 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.

Stream messages 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 primitives 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 Java 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 NullPointerException.

See Also:

Session.createStreamMessage(), BytesMessage, MapMessage, Message, ObjectMessage, TextMessage

Fields inherited from interface javax.jms.Message

DEFAULT_DELIVERY_MODE, DEFAULT_PRIORITY, DEFAULT_TIME_TO_LIVE

Method Summary

boolean	readBoolean() Read a boolean from the stream message.
byte	readByte() Read a byte value from the stream message.
int	readBytes(byte[] value) Read a byte array field from the stream message into the specified byte[] object (the read buffer).
char	readChar() Read a Unicode character value from the stream message.
double	readDouble() Read a double from the stream message.
float	readFloat() Read a float from the stream message.
int	readInt() Read a 32-bit integer from the stream message.
long	readLong() Read a 64-bit integer from the stream message.
java.lang.Object	readObject() Read a Java object from the stream message.
short	readShort() Read a 16-bit number from the stream message.
java.lang.String	readString() Read in a string from the stream message.
void	reset() Put the message body in read-only mode, and reposition the stream to the beginning.
void	writeBoolean(boolean value) Write a boolean to the stream message.
void	writeByte(byte value) Write out a byte to the stream message.
void	writeBytes(byte[] value) Write a byte array field to the stream message.
void	writeBytes(byte[] value, int offset, int length) Write a portion of a byte array as a byte array field to the stream message.
void	writeChar(char value) Write a char to the stream message.
void	writeDouble(double value) Write a double to the stream message.
void	writeFloat(float value) Write a float to the stream message.
void	writeInt(int value) Write an int to the stream message.
void	writeLong(long value) Write a long to the stream message.
void	writeObject(java.lang.Object value) Write a Java object to the stream message.
void	writeShort(short value) Write a short to the stream message.
void	writeString(java.lang.String value) Write a string to the stream message.

Methods inherited from interface javax.jms.Message

acknowledge, clearBody, 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, setObjectProperty, setShortProperty, setStringProperty

Method Detail

readBoolean

public boolean readBoolean()
                    throws JMSException

Read a boolean from the stream message.

Returns:

the boolean value read.

Throws:

JMSException - if JMS fails to read message due to some internal JMS error.

MessageEOFException - if an end of message stream

MessageFormatException - if this type conversion is invalid

MessageNotReadableException - if message in write-only mode.

readByte

public byte readByte()
              throws JMSException

Read a byte value from the stream message.

Returns:

the next byte from the stream message as a 8-bit byte.

Throws:

JMSException - if JMS fails to read message due to some internal JMS error.

MessageEOFException - if an end of message stream

MessageFormatException - if this type conversion is invalid

MessageNotReadableException - if message in write-only mode.

readShort

public short readShort()
                throws JMSException

Read a 16-bit number from the stream message.

Returns:

a 16-bit number from the stream message.

Throws:

JMSException - if JMS fails to read message due to some internal JMS error.

MessageEOFException - if an end of message stream

MessageFormatException - if this type conversion is invalid

MessageNotReadableException - if message in write-only mode.

readChar

public char readChar()
              throws JMSException

Read a Unicode character value from the stream message.

Returns:

a Unicode character from the stream message.

Throws:

JMSException - if JMS fails to read message due to some internal JMS error.

MessageEOFException - if an end of message stream

MessageFormatException - if this type conversion is invalid

MessageNotReadableException - if message in write-only mode.

readInt

public int readInt()
            throws JMSException

Read a 32-bit integer from the stream message.

Returns:

a 32-bit integer value from the stream message, interpreted as a int.

Throws:

JMSException - if JMS fails to read message due to some internal JMS error.

MessageEOFException - if an end of message stream

MessageFormatException - if this type conversion is invalid

MessageNotReadableException - if message in write-only mode.

readLong

public long readLong()
              throws JMSException

Read a 64-bit integer from the stream message.

Returns:

a 64-bit integer value from the stream message, interpreted as a long.

Throws:

JMSException - if JMS fails to read message due to some internal JMS error.

MessageEOFException - if an end of message stream

MessageFormatException - if this type conversion is invalid

MessageNotReadableException - if message in write-only mode.

readFloat

public float readFloat()
                throws JMSException

Read a float from the stream message.

Returns:

a float value from the stream message.

Throws:

JMSException - if JMS fails to read message due to some internal JMS error.

MessageEOFException - if an end of message stream

MessageFormatException - if this type conversion is invalid

MessageNotReadableException - if message in write-only mode.

readDouble

public double readDouble()
                  throws JMSException

Read a double from the stream message.

Returns:

a double value from the stream message.

Throws:

JMSException - if JMS fails to read message due to some internal JMS error.

MessageEOFException - if an end of message stream

MessageFormatException - if this type conversion is invalid

MessageNotReadableException - if message in write-only mode.

readString

public java.lang.String readString()
                            throws JMSException

Read in a string from the stream message.

Returns:

a Unicode string from the stream message.

Throws:

JMSException - if JMS fails to read message due to some internal JMS error.

MessageEOFException - if an end of message stream

MessageFormatException - if this type conversion is invalid

MessageNotReadableException - if message in write-only mode.

readBytes

public int readBytes(byte[] value)
              throws JMSException

Read 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 are 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 will return -1.

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

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

Once the first readBytes call on a byte[] field value has been done, 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.

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 byte field has been reached.

Throws:

JMSException - if JMS fails to read message due to some internal JMS error.

MessageFormatException - if this type conversion is invalid

MessageEOFException - if an end of message stream

MessageNotReadableException - if message in write-only mode.

See Also:

readObject()

readObject

public java.lang.Object readObject()
                            throws JMSException

Read a Java object from the stream message.

Note that this method can be used to return in objectified format, an object that had been written to the Stream with the equivalent writeObject method call, or it's equivalent primitive write method.

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

Returns:

a Java object from the stream message, in objectified format (ie. if it set as an int, then a Integer is returned).

Throws:

JMSException - if JMS fails to read message due to some internal JMS error.

MessageEOFException - if an end of message stream

MessageNotReadableException - if message in write-only mode.

writeBoolean

public void writeBoolean(boolean value)
                  throws JMSException

Write a boolean to the stream message. The value true is written out as the value (byte)1; the value false is written out as the value (byte)0.

Parameters:

value - the boolean value to be written.

Throws:

JMSException - if JMS fails to read message due to some internal JMS error.

MessageNotWriteableException - if message in read-only mode.

writeByte

public void writeByte(byte value)
               throws JMSException

Write out a byte to the stream message.

Parameters:

value - the byte value to be written.

Throws:

JMSException - if JMS fails to write message due to some internal JMS error.

MessageNotWriteableException - if message in read-only mode.

writeShort

public void writeShort(short value)
                throws JMSException

Write a short to the stream message.

Parameters:

value - the short to be written.

Throws:

JMSException - if JMS fails to write message due to some internal JMS error.

MessageNotWriteableException - if message in read-only mode.

writeChar

public void writeChar(char value)
               throws JMSException

Write a char to the stream message.

Parameters:

value - the char value to be written.

Throws:

JMSException - if JMS fails to write message due to some internal JMS error.

MessageNotWriteableException - if message in read-only mode.

writeInt

public void writeInt(int value)
              throws JMSException

Write an int to the stream message.

Parameters:

value - the int to be written.

Throws:

JMSException - if JMS fails to write message due to some internal JMS error.

MessageNotWriteableException - if message in read-only mode.

writeLong

public void writeLong(long value)
               throws JMSException

Write a long to the stream message.

Parameters:

value - the long to be written.

Throws:

JMSException - if JMS fails to write message due to some internal JMS error.

MessageNotWriteableException - if message in read-only mode.

writeFloat

public void writeFloat(float value)
                throws JMSException

Write a float to the stream message.

Parameters:

value - the float value to be written.

Throws:

JMSException - if JMS fails to write message due to some internal JMS error.

MessageNotWriteableException - if message in read-only mode.

writeDouble

public void writeDouble(double value)
                 throws JMSException

Write a double to the stream message.

Parameters:

value - the double value to be written.

Throws:

JMSException - if JMS fails to write message due to some internal JMS error.

MessageNotWriteableException - if message in read-only mode.

writeString

public void writeString(java.lang.String value)
                 throws JMSException

Write a string to the stream message.

Parameters:

value - the String value to be written.

Throws:

JMSException - if JMS fails to write message due to some internal JMS error.

MessageNotWriteableException - if message in read-only mode.

writeBytes

public void writeBytes(byte[] value)
                throws JMSException

Write a byte array field to the stream message.

The byte array value is written as a byte array field into the StreamMessage. Consecutively written byte array fields are treated as two distinct fields when reading byte array fields.

Parameters:

value - the byte array to be written.

Throws:

JMSException - if JMS fails to write message due to some internal JMS error.

MessageNotWriteableException - if message in read-only mode.

writeBytes

public void writeBytes(byte[] value,
                       int offset,
                       int length)
                throws JMSException

Write 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 as a byte array field into the StreamMessage. Consecutively written byte array fields are treated as two distinct fields when reading byte array fields.

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 JMS fails to write message due to some internal JMS error.

MessageNotWriteableException - if message in read-only mode.

writeObject

public void writeObject(java.lang.Object value)
                 throws JMSException

Write a Java object to the stream message.

Note that this method only works for the objectified primitive object types (Integer, Double, Long ...), String's and byte arrays.

Parameters:

value - the Java object to be written.

Throws:

JMSException - if JMS fails to write message due to some internal JMS error.

MessageNotWriteableException - if message in read-only mode.

MessageFormatException - if the object is invalid

reset

public void reset()
           throws JMSException

Put the message body in read-only mode, and reposition the stream to the beginning.

Throws:

JMSException - if JMS fails to reset the message due to some internal JMS error.

MessageFormatException - if message has an invalid format