package javax.jms;

import java.io.Serializable;

/** <P>A <CODE>Session</CODE> object is a single-threaded context for producing and consuming 
 * messages. Although it may allocate provider resources outside the Java 
 * virtual machine (JVM), it is considered a lightweight JMS object.
 *
 * <P>A session serves several purposes:
 *
 * <UL>
 *   <LI>It is a factory for its message producers and consumers.
 *   <LI>It supplies provider-optimized message factories.
 *   <LI>It is a factory for <CODE>TemporaryTopics</CODE> and 
 *        <CODE>TemporaryQueues</CODE>. 
 *   <LI> It provides a way to create <CODE>Queue</CODE> or <CODE>Topic</CODE>
 *      objects for those clients that need to dynamically manipulate 
 *      provider-specific destination names.
 *   <LI>It supports a single series of transactions that combine work 
 *       spanning its producers and consumers into atomic units.
 *   <LI>It defines a serial order for the messages it consumes and 
 *       the messages it produces.
 *   <LI>It retains messages it consumes until they have been 
 *       acknowledged.
 *   <LI>It serializes execution of message listeners registered with 
 *       its message consumers.
 *   <LI> It is a factory for <CODE>QueueBrowsers</CODE>.
 * </UL>
 *
 * <P>A session can create and service multiple message producers and 
 * consumers.
 *
 * <P>One typical use is to have a thread block on a synchronous 
 * <CODE>MessageConsumer</CODE> until a message arrives. The thread may then
 * use one or more of the <CODE>Session</CODE>'s <CODE>MessageProducer</CODE>s.
 *
 * <P>If a client desires to have one thread produce messages while others 
 * consume them, the client should use a separate session for its producing 
 * thread.
 *
 * <P>Once a connection has been started, any session with one or more 
 * registered message listeners is dedicated to the thread of control that 
 * delivers messages to it. It is erroneous for client code to use this session
 * or any of its constituent objects from another thread of control. The
 * only exception to this rule is the use of the session or connection 
 * <CODE>close</CODE> method.
 *
 * <P>It should be easy for most clients to partition their work naturally
 * into sessions. This model allows clients to start simply and incrementally
 * add message processing complexity as their need for concurrency grows.
 *
 * <P>The <CODE>close</CODE> method is the only session method that can be 
 * called while some other session method is being executed in another thread.
 *
 * <P>A session may be specified as transacted. Each transacted 
 * session supports a single series of transactions. Each transaction groups 
 * a set of message sends and a set of message receives into an atomic unit 
 * of work. In effect, transactions organize a session's input message 
 * stream and output message stream into series of atomic units. When a 
 * transaction commits, its atomic unit of input is acknowledged and its 
 * associated atomic unit of output is sent. If a transaction rollback is 
 * done, the transaction's sent messages are destroyed and the session's input 
 * is automatically recovered.
 *
 * <P>The content of a transaction's input and output units is simply those 
 * messages that have been produced and consumed within the session's current 
 * transaction.
 *
 * <P>A transaction is completed using either its session's <CODE>commit</CODE>
 * method or its session's <CODE>rollback</CODE> method. The completion of a
 * session's current transaction automatically begins the next. The result is
 * that a transacted session always has a current transaction within which its 
 * work is done.  
 *
 * <P>The Java Transaction Service (JTS) or some other transaction monitor may 
 * be used to combine a session's transaction with transactions on other 
 * resources (databases, other JMS sessions, etc.). Since Java distributed 
 * transactions are controlled via the Java Transaction API (JTA), use of the 
 * session's <CODE>commit</CODE> and <CODE>rollback</CODE> methods in 
 * this context is prohibited.
 *
 * <P>The JMS API does not require support for JTA; however, it does define 
 * how a provider supplies this support.
 *
 * <P>Although it is also possible for a JMS client to handle distributed 
 * transactions directly, it is unlikely that many JMS clients will do this.
 * Support for JTA in the JMS API is targeted at systems vendors who will be 
 * integrating the JMS API into their application server products.
 *
 * @see         javax.jms.QueueSession
 * @see         javax.jms.TopicSession
 * @see         javax.jms.XASession
 */

public interface Session extends Runnable
{

   /** With this acknowledgment mode, the session automatically acknowledges
    * a client's receipt of a message either when the session has successfully 
    * returned from a call to <CODE>receive</CODE> or when the message 
    * listener the session has called to process the message successfully 
    * returns.
    */

   static final int AUTO_ACKNOWLEDGE = 1;

   /** With this acknowledgment mode, the client acknowledges a consumed 
    * message by calling the message's <CODE>acknowledge</CODE> method. 
    * Acknowledging a consumed message acknowledges all messages that the 
    * session has consumed.
    *
    * <P>When client acknowledgment mode is used, a client may build up a 
    * large number of unacknowledged messages while attempting to process 
    * them. A JMS provider should provide administrators with a way to 
    * limit client overrun so that clients are not driven to resource 
    * exhaustion and ensuing failure when some resource they are using 
    * is temporarily blocked.
    *
    * @see javax.jms.Message#acknowledge()
    */

   static final int CLIENT_ACKNOWLEDGE = 2;

   /** This acknowledgment mode instructs the session to lazily acknowledge 
    * the delivery of messages. This is likely to result in the delivery of 
    * some duplicate messages if the JMS provider fails, so it should only be 
    * used by consumers that can tolerate duplicate messages. Use of this  
    * mode can reduce session overhead by minimizing the work the 
    * session does to prevent duplicates.
    */

   static final int DUPS_OK_ACKNOWLEDGE = 3;

   /** This value is returned from the method 
    * <CODE>getAcknowledgeMode</CODE> if the session is transacted.
    * If a <CODE>Session</CODE> is transacted, the acknowledgement mode
    * is ignored.
    */
   static final int SESSION_TRANSACTED = 0;

   /** Creates a <CODE>BytesMessage</CODE> object. A <CODE>BytesMessage</CODE> 
    * object is used to send a message containing a stream of uninterpreted 
    * bytes.
    *  
    * @exception JMSException if the JMS provider fails to create this message
    *                         due to some internal error.
    */

   BytesMessage createBytesMessage() throws JMSException;

   /** Creates a <CODE>MapMessage</CODE> object. A <CODE>MapMessage</CODE> 
    * object is used to send a self-defining set of name-value pairs, where 
    * names are <CODE>String</CODE> objects and values are primitive values 
    * in the Java programming language.
    *  
    * @exception JMSException if the JMS provider fails to create this message
    *                         due to some internal error.
    */

   MapMessage createMapMessage() throws JMSException;

   /** Creates a <CODE>Message</CODE> object. The <CODE>Message</CODE> 
    * interface is the root interface of all JMS messages. A 
    * <CODE>Message</CODE> object holds all the 
    * standard message header information. It can be sent when a message 
    * containing only header information is sufficient.
    *  
    * @exception JMSException if the JMS provider fails to create this message
    *                         due to some internal error.
    */

   Message createMessage() throws JMSException;

   /** Creates an <CODE>ObjectMessage</CODE> object. An 
    * <CODE>ObjectMessage</CODE> object is used to send a message 
    * that contains a serializable Java object.
    *  
    * @exception JMSException if the JMS provider fails to create this message
    *                         due to some internal error.
    */

   ObjectMessage createObjectMessage() throws JMSException;

   /** Creates an initialized <CODE>ObjectMessage</CODE> object. An 
    * <CODE>ObjectMessage</CODE> object is used 
    * to send a message that contains a serializable Java object.
    *  
    * @param object the object to use to initialize this message
    *
    * @exception JMSException if the JMS provider fails to create this message
    *                         due to some internal error.
    */

   ObjectMessage createObjectMessage(Serializable object) throws JMSException;

   /** Creates a <CODE>StreamMessage</CODE> object. A 
    * <CODE>StreamMessage</CODE> object is used to send a 
    * self-defining stream of primitive values in the Java programming 
    * language.
    *  
    * @exception JMSException if the JMS provider fails to create this message
    *                         due to some internal error.
    */

   StreamMessage createStreamMessage() throws JMSException;

   /** Creates a <CODE>TextMessage</CODE> object. A <CODE>TextMessage</CODE> 
    * object is used to send a message containing a <CODE>String</CODE>
    * object.
    *  
    * @exception JMSException if the JMS provider fails to create this message
    *                         due to some internal error.
    */

   TextMessage createTextMessage() throws JMSException;

   /** Creates an initialized <CODE>TextMessage</CODE> object. A 
    * <CODE>TextMessage</CODE> object is used to send 
    * a message containing a <CODE>String</CODE>.
    *
    * @param text the string used to initialize this message
    *
    * @exception JMSException if the JMS provider fails to create this message
    *                         due to some internal error.
    */

   TextMessage createTextMessage(String text) throws JMSException;

   /** Indicates whether the session is in transacted mode.
    *  
    * @return true if the session is in transacted mode
    *  
    * @exception JMSException if the JMS provider fails to return the 
    *                         transaction mode due to some internal error.
    */

   boolean getTransacted() throws JMSException;

   /** Returns the acknowledgement mode of the session. The acknowledgement
    * mode is set at the time that the session is created. If the session is
    * transacted, the acknowledgement mode is ignored.
    *
    *@return            If the session is not transacted, returns the 
    *                  current acknowledgement mode for the session.
    *                  If the session
    *                  is transacted, returns SESSION_TRANSACTED.
    *
    *@exception JMSException   if the JMS provider fails to return the 
    *                         acknowledgment mode due to some internal error.
    *
    *@see Connection#createSession
    *@since 1.1
    */
   int getAcknowledgeMode() throws JMSException;

   /** Commits all messages done in this transaction and releases any locks
    * currently held.
    *
    * @exception JMSException if the JMS provider fails to commit the
    *                         transaction due to some internal error.
    * @exception TransactionRolledBackException if the transaction
    *                         is rolled back due to some internal error
    *                         during commit.
    * @exception IllegalStateException if the method is not called by a 
    *                         transacted session.
    */

   void commit() throws JMSException;

   /** Rolls back any messages done in this transaction and releases any locks 
    * currently held.
    *
    * @exception JMSException if the JMS provider fails to roll back the
    *                         transaction due to some internal error.
    * @exception IllegalStateException if the method is not called by a 
    *                         transacted session.
    *                                     
    */

   void rollback() throws JMSException;

   /** Closes the session.
    *
    * <P>Since a provider may allocate some resources on behalf of a session 
    * outside the JVM, clients should close the resources when they are not 
    * needed. 
    * Relying on garbage collection to eventually reclaim these resources 
    * may not be timely enough.
    *
    * <P>There is no need to close the producers and consumers
    * of a closed session. 
    *
    * <P> This call will block until a <CODE>receive</CODE> call or message 
    * listener in progress has completed. A blocked message consumer
    * <CODE>receive</CODE> call returns <CODE>null</CODE> when this session 
    * is closed.
    *
    * <P>Closing a transacted session must roll back the transaction
    * in progress.
    * 
    * <P>This method is the only <CODE>Session</CODE> method that can 
    * be called concurrently. 
    *
    * <P>Invoking any other <CODE>Session</CODE> method on a closed session 
    * must throw a <CODE>JMSException.IllegalStateException</CODE>. Closing a 
    * closed session must <I>not</I> throw an exception.
    * 
    * @exception JMSException if the JMS provider fails to close the
    *                         session due to some internal error.
    */

   void close() throws JMSException;

   /** Stops message delivery in this session, and restarts message delivery
    * with the oldest unacknowledged message.
    *  
    * <P>All consumers deliver messages in a serial order.
    * Acknowledging a received message automatically acknowledges all 
    * messages that have been delivered to the client.
    *
    * <P>Restarting a session causes it to take the following actions:
    *
    * <UL>
    *   <LI>Stop message delivery
    *   <LI>Mark all messages that might have been delivered but not 
    *       acknowledged as "redelivered"
    *   <LI>Restart the delivery sequence including all unacknowledged 
    *       messages that had been previously delivered. Redelivered messages
    *       do not have to be delivered in 
    *       exactly their original delivery order.
    * </UL>
    *
    * @exception JMSException if the JMS provider fails to stop and restart
    *                         message delivery due to some internal error.
    * @exception IllegalStateException if the method is called by a 
    *                         transacted session.
    */

   void recover() throws JMSException;

   /** Returns the session's distinguished message listener (optional).
    *
    * @return the message listener associated with this session
    *
    * @exception JMSException if the JMS provider fails to get the message 
    *                         listener due to an internal error.
    *
    * @see javax.jms.Session#setMessageListener
    * @see javax.jms.ServerSessionPool
    * @see javax.jms.ServerSession
    */

   MessageListener getMessageListener() throws JMSException;

   /** Sets the session's distinguished message listener (optional).
    *
    * <P>When the distinguished message listener is set, no other form of 
    * message receipt in the session can 
    * be used; however, all forms of sending messages are still supported.
    * 
    * <P>This is an expert facility not used by regular JMS clients.
    *
    * @param listener the message listener to associate with this session
    *
    * @exception JMSException if the JMS provider fails to set the message 
    *                         listener due to an internal error.
    *
    * @see javax.jms.Session#getMessageListener
    * @see javax.jms.ServerSessionPool
    * @see javax.jms.ServerSession
    */

   void setMessageListener(MessageListener listener) throws JMSException;

   /**
    * Optional operation, intended to be used only by Application Servers,
    * not by ordinary JMS clients.
    *
    * @see javax.jms.ServerSession
    */
   public void run();

   /** Creates a <CODE>MessageProducer</CODE> to send messages to the specified 
    * destination.
    *
    * <P>A client uses a <CODE>MessageProducer</CODE> object to send 
    * messages to a destination. Since <CODE>Queue</CODE> and <CODE>Topic</CODE> 
    * both inherit from <CODE>Destination</CODE>, they can be used in
    * the destination parameter to create a <CODE>MessageProducer</CODE> object.
    * 
    * @param destination the <CODE>Destination</CODE> to send to, 
    * or null if this is a producer which does not have a specified 
    * destination.
    *
    * @exception JMSException if the session fails to create a MessageProducer
    *                         due to some internal error.
    * @exception InvalidDestinationException if an invalid destination
    * is specified.
    *
    * @since 1.1 
    * 
    */
   public MessageProducer createProducer(Destination destination) throws JMSException;

   /** Creates a <CODE>MessageConsumer</CODE> for the specified destination.
    * Since <CODE>Queue</CODE> and <CODE>Topic</CODE> 
    * both inherit from <CODE>Destination</CODE>, they can be used in
    * the destination parameter to create a <CODE>MessageConsumer</CODE>.
    *
    * @param destination the <CODE>Destination</CODE> to access. 
    *
    * @exception JMSException if the session fails to create a consumer
    *                         due to some internal error.
    * @exception InvalidDestinationException if an invalid destination 
    *                         is specified.
    *
    * @since 1.1 
    */
   public MessageConsumer createConsumer(Destination destination) throws JMSException;

   /** Creates a <CODE>MessageConsumer</CODE> for the specified destination, 
    * using a message selector. 
    * Since <CODE>Queue</CODE> and <CODE>Topic</CODE> 
    * both inherit from <CODE>Destination</CODE>, they can be used in
    * the destination parameter to create a <CODE>MessageConsumer</CODE>.
    *
    * <P>A client uses a <CODE>MessageConsumer</CODE> object to receive 
    * messages that have been sent to a destination.
    *  
    *       
    * @param destination the <CODE>Destination</CODE> to access
    * @param messageSelector only messages with properties matching the
    * message selector expression are delivered. A value of null or
    * an empty string indicates that there is no message selector 
    * for the message consumer. 
    * 
    *  
    * @exception JMSException if the session fails to create a MessageConsumer
    *                         due to some internal error.
    * @exception InvalidDestinationException if an invalid destination
    * is specified.
    
    * @exception InvalidSelectorException if the message selector is invalid.
    *
    * @since 1.1 
    */
   MessageConsumer createConsumer(Destination destination, java.lang.String messageSelector) throws JMSException;

   /** Creates <CODE>MessageConsumer</CODE> for the specified destination, using a
    * message selector. This method can specify whether messages published by 
    * its own connection should be delivered to it, if the destination is a 
    * topic. 
    *<P> Since <CODE>Queue</CODE> and <CODE>Topic</CODE> 
    * both inherit from <CODE>Destination</CODE>, they can be used in
    * the destination parameter to create a <CODE>MessageConsumer</CODE>.
    * <P>A client uses a <CODE>MessageConsumer</CODE> object to receive 
    * messages that have been published to a destination. 
    *               
    * <P>In some cases, a connection may both publish and subscribe to a 
    * topic. The consumer <CODE>NoLocal</CODE> attribute allows a consumer
    * to inhibit the delivery of messages published by its own connection.
    * The default value for this attribute is False. The <CODE>noLocal</CODE> 
    * value must be supported by destinations that are topics. 
    *
    * @param destination the <CODE>Destination</CODE> to access 
    * @param messageSelector only messages with properties matching the
    * message selector expression are delivered. A value of null or
    * an empty string indicates that there is no message selector 
    * for the message consumer.
    * @param NoLocal  - if true, and the destination is a topic,
    *                   inhibits the delivery of messages published
    *                   by its own connection.  The behavior for
    *                   <CODE>NoLocal</CODE> is 
    *                   not specified if the destination is a queue.
    * 
    * @exception JMSException if the session fails to create a MessageConsumer
    *                         due to some internal error.
    * @exception InvalidDestinationException if an invalid destination
    * is specified.
    
    * @exception InvalidSelectorException if the message selector is invalid.
    *
    * @since 1.1 
    *
    */
   MessageConsumer createConsumer(Destination destination, java.lang.String messageSelector, boolean NoLocal)
         throws JMSException;

   /** Creates a queue identity given a <CODE>Queue</CODE> name.
    *
    * <P>This facility is provided for the rare cases where clients need to
    * dynamically manipulate queue identity. It allows the creation of a
    * queue identity with a provider-specific name. Clients that depend 
    * on this ability are not portable.
    *
    * <P>Note that this method is not for creating the physical queue. 
    * The physical creation of queues is an administrative task and is not
    * to be initiated by the JMS API. The one exception is the
    * creation of temporary queues, which is accomplished with the 
    * <CODE>createTemporaryQueue</CODE> method.
    *
    * @param queueName the name of this <CODE>Queue</CODE>
    *
    * @return a <CODE>Queue</CODE> with the given name
    *
    * @exception JMSException if the session fails to create a queue
    *                         due to some internal error.
    * @since 1.1
    */

   Queue createQueue(String queueName) throws JMSException;

   /** Creates a topic identity given a <CODE>Topic</CODE> name.
    *
    * <P>This facility is provided for the rare cases where clients need to
    * dynamically manipulate topic identity. This allows the creation of a
    * topic identity with a provider-specific name. Clients that depend 
    * on this ability are not portable.
    *
    * <P>Note that this method is not for creating the physical topic. 
    * The physical creation of topics is an administrative task and is not
    * to be initiated by the JMS API. The one exception is the
    * creation of temporary topics, which is accomplished with the 
    * <CODE>createTemporaryTopic</CODE> method.
    *  
    * @param topicName the name of this <CODE>Topic</CODE>
    *
    * @return a <CODE>Topic</CODE> with the given name
    *
    * @exception JMSException if the session fails to create a topic
    *                         due to some internal error.
    * @since 1.1
    */

   Topic createTopic(String topicName) throws JMSException;

   /** Creates a <CODE>QueueBrowser</CODE> object to peek at the messages on 
    * the specified queue.
    *
    * @param queue the <CODE>queue</CODE> to access
    *
    * @exception InvalidDestinationException if an invalid destination
    *                         is specified 
    *
    * @since 1.1 
    */

   /** Creates a durable subscriber to the specified topic.
    *  
    * <P>If a client needs to receive all the messages published on a 
    * topic, including the ones published while the subscriber is inactive,
    * it uses a durable <CODE>TopicSubscriber</CODE>. The JMS provider
    * retains a record of this 
    * durable subscription and insures that all messages from the topic's 
    * publishers are retained until they are acknowledged by this 
    * durable subscriber or they have expired.
    *
    * <P>Sessions with durable subscribers must always provide the same 
    * client identifier. In addition, each client must specify a name that 
    * uniquely identifies (within client identifier) each durable 
    * subscription it creates. Only one session at a time can have a 
    * <CODE>TopicSubscriber</CODE> for a particular durable subscription.
    *
    * <P>A client can change an existing durable subscription by creating 
    * a durable <CODE>TopicSubscriber</CODE> with the same name and a new 
    * topic and/or 
    * message selector. Changing a durable subscriber is equivalent to 
    * unsubscribing (deleting) the old one and creating a new one.
    *
    * <P>In some cases, a connection may both publish and subscribe to a 
    * topic. The subscriber <CODE>NoLocal</CODE> attribute allows a subscriber
    * to inhibit the delivery of messages published by its own connection.
    * The default value for this attribute is false.
    *
    * @param topic the non-temporary <CODE>Topic</CODE> to subscribe to
    * @param name the name used to identify this subscription
    *  
    * @exception JMSException if the session fails to create a subscriber
    *                         due to some internal error.
    * @exception InvalidDestinationException if an invalid topic is specified.
    *
    * @since 1.1
    */

   TopicSubscriber createDurableSubscriber(Topic topic, String name) throws JMSException;

   /** Creates a durable subscriber to the specified topic, using a
    * message selector and specifying whether messages published by its
    * own connection should be delivered to it.
    *  
    * <P>If a client needs to receive all the messages published on a 
    * topic, including the ones published while the subscriber is inactive,
    * it uses a durable <CODE>TopicSubscriber</CODE>. The JMS provider
    * retains a record of this 
    * durable subscription and insures that all messages from the topic's 
    * publishers are retained until they are acknowledged by this 
    * durable subscriber or they have expired.
    *
    * <P>Sessions with durable subscribers must always provide the same
    * client identifier. In addition, each client must specify a name which
    * uniquely identifies (within client identifier) each durable
    * subscription it creates. Only one session at a time can have a
    * <CODE>TopicSubscriber</CODE> for a particular durable subscription.
    * An inactive durable subscriber is one that exists but
    * does not currently have a message consumer associated with it.
    *
    * <P>A client can change an existing durable subscription by creating 
    * a durable <CODE>TopicSubscriber</CODE> with the same name and a new 
    * topic and/or 
    * message selector. Changing a durable subscriber is equivalent to 
    * unsubscribing (deleting) the old one and creating a new one.
    *
    * @param topic the non-temporary <CODE>Topic</CODE> to subscribe to
    * @param name the name used to identify this subscription
    * @param messageSelector only messages with properties matching the
    * message selector expression are delivered.  A value of null or
    * an empty string indicates that there is no message selector 
    * for the message consumer.
    * @param noLocal if set, inhibits the delivery of messages published
    * by its own connection
    *  
    * @exception JMSException if the session fails to create a subscriber
    *                         due to some internal error.
    * @exception InvalidDestinationException if an invalid topic is specified.
    * @exception InvalidSelectorException if the message selector is invalid.
    *
    * @since 1.1
    */

   TopicSubscriber createDurableSubscriber(Topic topic, String name, String messageSelector, boolean noLocal)
         throws JMSException;

   /** Creates a <CODE>QueueBrowser</CODE> object to peek at the messages on 
    * the specified queue.
    *  
    * @param queue the <CODE>queue</CODE> to access
    *
    *  
    * @exception JMSException if the session fails to create a browser
    *                         due to some internal error.
    * @exception InvalidDestinationException if an invalid destination
    *                         is specified 
    *
    * @since 1.1 
    */
   QueueBrowser createBrowser(Queue queue) throws JMSException;

   /** Creates a <CODE>QueueBrowser</CODE> object to peek at the messages on 
    * the specified queue using a message selector.
    *  
    * @param queue the <CODE>queue</CODE> to access
    *
    * @param messageSelector only messages with properties matching the
    * message selector expression are delivered. A value of null or
    * an empty string indicates that there is no message selector 
    * for the message consumer.
    *  
    * @exception JMSException if the session fails to create a browser
    *                         due to some internal error.
    * @exception InvalidDestinationException if an invalid destination
    *                         is specified 
    * @exception InvalidSelectorException if the message selector is invalid.
    *
    * @since 1.1 
    */

   QueueBrowser createBrowser(Queue queue, String messageSelector) throws JMSException;

   /** Creates a <CODE>TemporaryQueue</CODE> object. Its lifetime will be that 
    * of the <CODE>Connection</CODE> unless it is deleted earlier.
    *
    * @return a temporary queue identity
    *
    * @exception JMSException if the session fails to create a temporary queue
    *                         due to some internal error.
    *
    *@since 1.1
    */

   TemporaryQueue createTemporaryQueue() throws JMSException;

   /** Creates a <CODE>TemporaryTopic</CODE> object. Its lifetime will be that 
    * of the <CODE>Connection</CODE> unless it is deleted earlier.
    *
    * @return a temporary topic identity
    *
    * @exception JMSException if the session fails to create a temporary
    *                         topic due to some internal error.
    *
    * @since 1.1  
    */

   TemporaryTopic createTemporaryTopic() throws JMSException;

   /** Unsubscribes a durable subscription that has been created by a client.
    *  
    * <P>This method deletes the state being maintained on behalf of the 
    * subscriber by its provider.
    *
    * <P>It is erroneous for a client to delete a durable subscription
    * while there is an active <CODE>MessageConsumer</CODE>
    * or <CODE>TopicSubscriber</CODE> for the 
    * subscription, or while a consumed message is part of a pending 
    * transaction or has not been acknowledged in the session.
    *
    * @param name the name used to identify this subscription
    *  
    * @exception JMSException if the session fails to unsubscribe to the 
    *                         durable subscription due to some internal error.
    * @exception InvalidDestinationException if an invalid subscription name
    *                                        is specified.
    *
    * @since 1.1
    */

   void unsubscribe(String name) throws JMSException;

}
