O'Reilly - Java Message Service

2.1.2.3 The TopicConnectionFactory
Java Message Service
Once a JNDI InitialContext object is instantiated, it can be used to look up the
TopicConnectionFactory in the messaging server's naming service:
TopicConnectionFactory conFactory =
(TopicConnectionFactory)jndi.lookup("TopicConnectionFactory");
The javax.jms.TopicConnectionFactory is used to manufacture connections to a message
server. A TopicConnectionFactory is a type of administered object, which means that its
attributes and behavior are configured by the system administrator responsible for the
messaging server. The TopicConnectionFactory is implemented differently by each
vendor, so configuration options available to system administrators vary from product to
product. A connection factory might, for example, be configured to manufacture
connections that use a particular protocol, security scheme, clustering strategy, etc. A
system administrator might choose to deploy several different TopicConnectionFactory
objects, each configured with its own JNDI lookup name.
The TopicConnectionFactory provides two overloaded versions of the
createTopicConnection( ) method:
package javax.jms;
public interface TopicConnectionFactory extends ConnectionFactory {
public TopicConnection createTopicConnection( )
throws JMSException, JMSSecurityException;
public TopicConnection createTopicConnection(String username,
String password) throws JMSException, JMSSecurityException;
}
These methods are used to create TopicConnection objects. The behavior of the no-arg
method depends on the JMS provider. Some JMS providers will assume that the JMS
client is connecting under anonymous security context, while other providers may assume
that the credentials can be obtained from JNDI or the current thread. [1] The second method
provides the client with a username-password authentication credential, which can be used
to authenticate the connection. In our code, we choose to authenticate the connection
explicitly with a username and password.
[1] Thread-specific storage is used with the Java Authentication and Authorization Service ( JAAS) to
allow security credentials to transparently propagate between resources and applications.
2.1.2.4 The TopicConnection
The TopicConnection is created by the TopicConnectionFactory :
// Look up a JMS connection factory
TopicConnectionFactory conFactory =
(TopicConnectionFactory)jndi.lookup("TopicConnectionFactory");
// Create a JMS connection
TopicConnection connection =
conFactory.createTopicConnection(username, password);
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