Message
properties are additional headers that can be assigned to a message.
They provide the application developer or JMS vendor with the ability
to attach more information to a message. The
Message interface provides several accessor and
mutator methods for reading and writing properties.
Properties can have a
String value, or one of several
primitive (boolean,
byte, short,
int, long,
float, double) values. The
naming of properties, together with their values and conversion
rules, are strictly defined by JMS.
Properties
are name-value pairs. The
name, called the identifier, can be just about any
String that is a valid identifier in the Java
language. With a couple of exceptions, the rules that apply to naming
a property are the same as those that apply to the naming of
variables. One difference between a JMS property name and a Java
variable name is that a property name can be any length. In addition,
property names are prohibited from using one of the
message selector
reserved words. These words include:
NOT, AND, OR
, BETWEEN, LIKE,
IN, IS,
NULL, TRUE, and
FALSE.
The property names used in JMS-defined properties and
provider-specific properties use predefined prefixes. These prefixes
(JMSX and JMS_) may not be used
for application property names.