Java Enterprise in a Nutshell, Second Edition

Name

MapMessage

Synopsis

A MapMessage has a set of name/value pairs as its message body. The names of the properties are Strings, and the values are Java primitive types. There are getXXX() and setXXX() methods for each primitive type, plus getObject() and setObject() methods for situations where the type of the value isn’t known until runtime. If a property is set to a value of a certain type, it has to be read back using a get method appropriate for that type, according to the following table:

if writ-
ten as:	boolean	byte	char	short	int	long	float	double	String	byte[]
can be
read as:
boolean		X								X
byte			X		X	X	X			X
char				X						X
short					X	X	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	X
byte[]										X

If a value is read using an inappropriate get method, then a MessageFormatException is thrown. The getMapNames() methods returns an Enumeration of names for the values in the MapMessage.

Clients that receive a MapMessage can only read the contents of the message, until they call clearBody() on the message. If a client tries to write values to the message before this, a MessageNotWriteableException will be thrown.

                  
public interface MapMessage extends javax.jms.Message {
// Public Instance Methods
   public abstract boolean getBoolean(
        String name) throws JMSException;  
   public abstract byte getByte(
        String name) throws JMSException; public ...