jrun.jms.core.client
Class JmsTopic

jrun.jms.core.client.JmsTopic

All Implemented Interfaces:

java.io.Externalizable, javax.naming.Referenceable, java.io.Serializable

public class JmsTopic

implements java.io.Externalizable, javax.naming.Referenceable

A topic is a destination specific for the puiblish-subscribe messaging model. OpenJMS also supports topic hierarchy and wild carding.

Version:

$Revision: 1.8 $ $Date: 2001/06/21 20:53:05 $

Author:

Jim Alateras, Jim Mourikis

See Also:

org.exolab.jms.client.JmsDestination, Serialized Form

Field Summary

static java.lang.String	ALL_WILDCARD
static java.lang.String	SEPARATOR
static java.lang.String	WILDCARD

Constructor Summary

JmsTopic()
Need a default constructor for the serialization

JmsTopic(java.lang.String name)
Instantiate an instance of this object with the specified string

Method Summary

boolean	equals(java.lang.Object object)
javax.naming.Reference	getReference()
java.lang.String	getTopicName() Return the name of the topic
int	hashCode()
boolean	isWildCard() Check whether this topic represents a wildcard expression.
boolean	match(JmsTopic destination) If it is a wildcard check to see that it matches the specified topic.
void	readExternal(java.io.ObjectInput stream)
void	writeExternal(java.io.ObjectOutput stream)

Field Detail

WILDCARD

public static final java.lang.String WILDCARD

ALL_WILDCARD

public static final java.lang.String ALL_WILDCARD

SEPARATOR

public static final java.lang.String SEPARATOR

Constructor Detail

JmsTopic

public JmsTopic()

Need a default constructor for the serialization

JmsTopic

public JmsTopic(java.lang.String name)

Instantiate an instance of this object with the specified string

Parameters:

name - name of the queue

Method Detail

getTopicName

public java.lang.String getTopicName()
                              throws javax.jms.JMSException

Return the name of the topic

Returns:

name name of the topic

Throws:

JMSException -

equals

public boolean equals(java.lang.Object object)

writeExternal

public void writeExternal(java.io.ObjectOutput stream)
                   throws java.io.IOException

Specified by:

writeExternal in interface java.io.Externalizable

readExternal

public void readExternal(java.io.ObjectInput stream)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException

Specified by:

readExternal in interface java.io.Externalizable

hashCode

public int hashCode()

isWildCard

public boolean isWildCard()
                   throws javax.jms.JMSException

Check whether this topic represents a wildcard expression.

Returns:

boolean true if the topic contains wildcards

Throws:

JMSException - error in retrieving dest

match

public boolean match(JmsTopic destination)

If it is a wildcard check to see that it matches the specified topic. if wildcard is **, its a an imediate match for every topic. else tokenize both the wildcard and the topic. if the wildcard has less or equal no of tokens than the topic and ends in "**" check tokens if both wildcard and topic contain the same no of tokens check tokens Otherwise topic and wildcard do not match so return false.

Note we treat "a.b.c.*.*" and "a.b.c" as not a match at this stage, since the wildcard is attempting to match more levels than exist in the topic. if this proves to be unpopular with the masses, its a very trivial change below to fix this problem.

Tokens are compared and must either be identical or the wildcard token must be a "*" to match at this level. Once a mismatch is detected the comparison is stopped and a false returned.

NOTE: This check assumes both the topic and wildcard topic have both already been validated. if the topics are inavlid this test can return arbitrary results.

Parameters:

destination - The specific topic to match to

Returns:

True if the wildcard matches.

getReference

public javax.naming.Reference getReference()

Specified by:

getReference in interface javax.naming.Referenceable