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.
StreamMessageobject is used to send a stream of primitive types in the Java programming language. It is filled and read sequentially. It inherits from theMessageinterface and adds a stream message body. Its methods are based largely on those found injava.io.DataInputStreamandjava.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 toStreamMessage.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
clearBodyis called, the body of the message is in write-only mode. After the first call toresethas 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 calledresetso that the message body is in read-only mode for the client.If
clearBodyis 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
MessageNotReadableExceptionis thrown.If a client attempts to write a message in read-only mode, a
MessageNotWriteableExceptionis thrown.StreamMessageobjects support the following conversion table. The marked cases must be supported. The unmarked cases must throw aJMSException. TheString-to-primitive conversions may throw a runtime exception if the primitive'svalueOf()method does not accept it as a validStringrepresentation of the primitive.A value written as the row type can be read as the column type.
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. Sincechardoes not support aStringconversion, attempting to read a null value as acharmust throw aNullPointerException.