javax.jms
Interface StreamMessage

All Superinterfaces:

Message

public interface StreamMessage

extends Message

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.

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()           Reads a boolean from the stream message.
byte	readByte()           Reads a byte value from the stream message.
int	readBytes(byte[] value)           Reads a byte array field from the stream message into the specified byte[] object (the read buffer).
char	readChar()           Reads a Unicode character value from the stream message.
double	readDouble()           Reads a double from the stream message.
float	readFloat()           Reads a float from the stream message.
int	readInt()           Reads a 32-bit integer from the stream message.
long	readLong()           Reads a 64-bit integer from the stream message.
Object	readObject()           Reads an object from the stream message.
short	readShort()           Reads a 16-bit integer from the stream message.
String	readString()           Reads a String from the stream message.
void	reset()           Puts the message body in read-only mode and repositions the stream to the beginning.
void	writeBoolean(boolean value)           Writes a boolean to the stream message.
void	writeByte(byte value)           Writes a byte to the stream message.
void	writeBytes(byte[] value)           Writes a byte array field to the stream message.
void