javax.jms.Connection Maven / Gradle / Ivy
/*
* @(#)Connection.java 1.22 02/04/09
*
* Copyright 1997-2002 Sun Microsystems, Inc. All Rights Reserved.
*
* SUN PROPRIETARY/CONFIDENTIAL.
* This software is the proprietary information of Sun Microsystems, Inc.
* Use is subject to license terms.
*
*/
package javax.jms;
/** A Connection object is a client's active connection to its JMS
* provider. It typically allocates provider resources outside the Java virtual
* machine (JVM).
*
* Connections support concurrent use.
*
*
A connection serves several purposes:
*
*
* - It encapsulates an open connection with a JMS provider. It
* typically represents an open TCP/IP socket between a client and
* the service provider software.
*
- Its creation is where client authentication takes place.
*
- It can specify a unique client identifier.
*
- It provides a
ConnectionMetaData object.
* - It supports an optional
ExceptionListener object.
*
*
* Because the creation of a connection involves setting up authentication
* and communication, a connection is a relatively heavyweight
* object. Most clients will do all their messaging with a single connection.
* Other more advanced applications may use several connections. The JMS API
* does
* not architect a reason for using multiple connections; however, there may
* be operational reasons for doing so.
*
*
A JMS client typically creates a connection, one or more sessions,
* and a number of message producers and consumers. When a connection is
* created, it is in stopped mode. That means that no messages are being
* delivered.
*
*
It is typical to leave the connection in stopped mode until setup
* is complete (that is, until all message consumers have been
* created). At that point, the client calls
* the connection's start method, and messages begin arriving at
* the connection's consumers. This setup
* convention minimizes any client confusion that may result from
* asynchronous message delivery while the client is still in the process
* of setting itself up.
*
*
A connection can be started immediately, and the setup can be done
* afterwards. Clients that do this must be prepared to handle asynchronous
* message delivery while they are still in the process of setting up.
*
*
A message producer can send messages while a connection is stopped.
*
* @version 1.1 - February 1, 2002
* @author Mark Hapner
* @author Rich Burridge
* @author Kate Stout
*
* @see javax.jms.ConnectionFactory
* @see javax.jms.QueueConnection
* @see javax.jms.TopicConnection
*/
public interface Connection {
/** Creates a Session object.
*
* @param transacted indicates whether the session is transacted
* @param acknowledgeMode indicates whether the consumer or the
* client will acknowledge any messages it receives; ignored if the session
* is transacted. Legal values are Session.AUTO_ACKNOWLEDGE,
* Session.CLIENT_ACKNOWLEDGE, and
* Session.DUPS_OK_ACKNOWLEDGE.
*
* @return a newly created session
*
* @exception JMSException if the Connection object fails
* to create a session due to some internal error or
* lack of support for the specific transaction
* and acknowledgement mode.
* @since 1.1
*
* @see Session#AUTO_ACKNOWLEDGE
* @see Session#CLIENT_ACKNOWLEDGE
* @see Session#DUPS_OK_ACKNOWLEDGE
*/
Session
createSession(boolean transacted,
int acknowledgeMode) throws JMSException;
/** Gets the client identifier for this connection.
*
*
This value is specific to the JMS provider. It is either preconfigured
* by an administrator in a ConnectionFactory object
* or assigned dynamically by the application by calling the
* setClientID method.
*
*
* @return the unique client identifier
*
* @exception JMSException if the JMS provider fails to return
* the client ID for this connection due
* to some internal error.
*
**/
String
getClientID() throws JMSException;
/** Sets the client identifier for this connection.
*
*
The preferred way to assign a JMS client's client identifier is for
* it to be configured in a client-specific ConnectionFactory
* object and transparently assigned to the Connection object
* it creates.
*
*
Alternatively, a client can set a connection's client identifier
* using a provider-specific value. The facility to set a connection's
* client identifier explicitly is not a mechanism for overriding the
* identifier that has been administratively configured. It is provided
* for the case where no administratively specified identifier exists.
* If one does exist, an attempt to change it by setting it must throw an
* IllegalStateException. If a client sets the client identifier
* explicitly, it must do so immediately after it creates the connection
* and before any other
* action on the connection is taken. After this point, setting the
* client identifier is a programming error that should throw an
* IllegalStateException.
*
*
The purpose of the client identifier is to associate a connection and
* its objects with a state maintained on behalf of the client by a
* provider. The only such state identified by the JMS API is that required
* to support durable subscriptions.
*
*
If another connection with the same clientID is already running when
* this method is called, the JMS provider should detect the duplicate ID and throw
* an InvalidClientIDException.
*
* @param clientID the unique client identifier
*
* @exception JMSException if the JMS provider fails to
* set the client ID for this connection due
* to some internal error.
*
* @exception InvalidClientIDException if the JMS client specifies an
* invalid or duplicate client ID.
* @exception IllegalStateException if the JMS client attempts to set
* a connection's client ID at the wrong time or
* when it has been administratively configured.
*/
void
setClientID(String clientID) throws JMSException;
/** Gets the metadata for this connection.
*
* @return the connection metadata
*
* @exception JMSException if the JMS provider fails to
* get the connection metadata for this connection.
*
* @see javax.jms.ConnectionMetaData
*/
ConnectionMetaData
getMetaData() throws JMSException;
/**
* Gets the ExceptionListener object for this connection.
* Not every Connection has an ExceptionListener
* associated with it.
*
* @return the ExceptionListener for this connection, or null.
* if no ExceptionListener is associated
* with this connection.
*
* @exception JMSException if the JMS provider fails to
* get the ExceptionListener for this
* connection.
* @see javax.jms.Connection#setExceptionListener
*/
ExceptionListener
getExceptionListener() throws JMSException;
/** Sets an exception listener for this connection.
*
*
If a JMS provider detects a serious problem with a connection, it
* informs the connection's ExceptionListener, if one has been
* registered. It does this by calling the listener's
* onException method, passing it a JMSException
* object describing the problem.
*
*
An exception listener allows a client to be notified of a problem
* asynchronously.
* Some connections only consume messages, so they would have no other
* way to learn their connection has failed.
*
*
A connection serializes execution of its
* ExceptionListener.
*
*
A JMS provider should attempt to resolve connection problems
* itself before it notifies the client of them.
*
* @param listener the exception listener
*
* @exception JMSException if the JMS provider fails to
* set the exception listener for this connection.
*
*/
void
setExceptionListener(ExceptionListener listener) throws JMSException;
/** Starts (or restarts) a connection's delivery of incoming messages.
* A call to start on a connection that has already been
* started is ignored.
*
* @exception JMSException if the JMS provider fails to start
* message delivery due to some internal error.
*
* @see javax.jms.Connection#stop
*/
void
start() throws JMSException;
/** Temporarily stops a connection's delivery of incoming messages.
* Delivery can be restarted using the connection's start
* method. When the connection is stopped,
* delivery to all the connection's message consumers is inhibited:
* synchronous receives block, and messages are not delivered to message
* listeners.
*
*
This call blocks until receives and/or message listeners in progress
* have completed.
*
*
Stopping a connection has no effect on its ability to send messages.
* A call to stop on a connection that has already been
* stopped is ignored.
*
*
A call to stop must not return until delivery of messages
* has paused. This means that a client can rely on the fact that none of
* its message listeners will be called and that all threads of control
* waiting for receive calls to return will not return with a
* message until the
* connection is restarted. The receive timers for a stopped connection
* continue to advance, so receives may time out while the connection is
* stopped.
*
*
If message listeners are running when stop is invoked,
* the stop call must
* wait until all of them have returned before it may return. While these
* message listeners are completing, they must have the full services of the
* connection available to them.
*
* @exception JMSException if the JMS provider fails to stop
* message delivery due to some internal error.
*
* @see javax.jms.Connection#start
*/
void
stop() throws JMSException;
/** Closes the connection.
*
*
Since a provider typically allocates significant resources outside
* the JVM on behalf of a connection, clients should close these resources
* when they are not needed. Relying on garbage collection to eventually
* reclaim these resources may not be timely enough.
*
*
There is no need to close the sessions, producers, and consumers
* of a closed connection.
*
*
Closing a connection causes all temporary destinations to be
* deleted.
*
*
When this method is invoked, it should not return until message
* processing has been shut down in an orderly fashion. This means that all
* message
* listeners that may have been running have returned, and that all pending
* receives have returned. A close terminates all pending message receives
* on the connection's sessions' consumers. The receives may return with a
* message or with null, depending on whether there was a message available
* at the time of the close. If one or more of the connection's sessions'
* message listeners is processing a message at the time when connection
* close is invoked, all the facilities of the connection and
* its sessions must remain available to those listeners until they return
* control to the JMS provider.
*
*
Closing a connection causes any of its sessions' transactions
* in progress to be rolled back. In the case where a session's
* work is coordinated by an external transaction manager, a session's
* commit and rollback methods are
* not used and the result of a closed session's work is determined
* later by the transaction manager.
*
* Closing a connection does NOT force an
* acknowledgment of client-acknowledged sessions.
*
*
Invoking the acknowledge method of a received message
* from a closed connection's session must throw an
* IllegalStateException. Closing a closed connection must
* NOT throw an exception.
*
* @exception JMSException if the JMS provider fails to close the
* connection due to some internal error. For
* example, a failure to release resources
* or to close a socket connection can cause
* this exception to be thrown.
*
*/
void
close() throws JMSException;
/** Creates a connection consumer for this connection (optional operation).
* This is an expert facility not used by regular JMS clients.
*
* @param destination the destination 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 sessionPool the server session pool to associate with this
* connection consumer
* @param maxMessages the maximum number of messages that can be
* assigned to a server session at one time
*
* @return the connection consumer
*
* @exception JMSException if the Connection object fails
* to create a connection consumer due to some
* internal error or invalid arguments for
* sessionPool and
* messageSelector.
* @exception InvalidDestinationException if an invalid destination is specified.
* @exception InvalidSelectorException if the message selector is invalid.
*
* @since 1.1
* @see javax.jms.ConnectionConsumer
*/
ConnectionConsumer
createConnectionConsumer(Destination destination,
String messageSelector,
ServerSessionPool sessionPool,
int maxMessages)
throws JMSException;
/** Create a durable connection consumer for this connection (optional operation).
* This is an expert facility not used by regular JMS clients.
*
* @param topic topic to access
* @param subscriptionName durable subscription name
* @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 sessionPool the server session pool to associate with this
* durable connection consumer
* @param maxMessages the maximum number of messages that can be
* assigned to a server session at one time
*
* @return the durable connection consumer
*
* @exception JMSException if the Connection object fails
* to create a connection consumer due to some
* internal error or invalid arguments for
* sessionPool and
* messageSelector.
* @exception InvalidDestinationException if an invalid destination
* is specified.
* @exception InvalidSelectorException if the message selector is invalid.
* @since 1.1
* @see javax.jms.ConnectionConsumer
*/
ConnectionConsumer
createDurableConnectionConsumer(Topic topic,
String subscriptionName,
String messageSelector,
ServerSessionPool sessionPool,
int maxMessages)
throws JMSException;
}