org.huihoo.jfox.ms.jms.base
Class MessageConsumerImpl

java.lang.Object
  org.huihoo.jfox.ms.jms.base.MessageConsumerImpl

All Implemented Interfaces:

javax.jms.MessageConsumer

Direct Known Subclasses:

QueueReceiverImpl, TopicSubscriberImpl

public abstract class MessageConsumerImpl

extends java.lang.Object

implements javax.jms.MessageConsumer

This class implements the JMS message producer. A client uses a MessageConsumer object to receive messages from a destination. A MessageConsumer object is created by passing a Destination object to a message-consumer creation method supplied by a session.

Version:

Revision: 1.1 Date: 2003-05-20 21:36:14

Author:

Peter.Cheng

Constructor Summary

MessageConsumerImpl(SessionImpl session, java.lang.String messageSelector)

Method Summary

void	close() Closes the message consumer.
javax.jms.MessageListener	getMessageListener() Gets the message consumer's MessageListener.
java.lang.String	getMessageSelector() Gets this message consumer's message selector expression.
boolean	isClosed() Indicates the status of this message consumer.
javax.jms.Message	receive() Receives the next message produced for this message consumer.
javax.jms.Message	receive(long timeout) Receives the next message that arrives within the specified timeout interval.
javax.jms.Message	receiveNoWait() Receives the next message if one is immediately available.Do not wait for a message to be recevied.
void	setMessageListener(javax.jms.MessageListener listener) ets the message consumer's MessageListener.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MessageConsumerImpl

public MessageConsumerImpl(SessionImpl session,
                           java.lang.String messageSelector)

Method Detail

getMessageListener

public javax.jms.MessageListener getMessageListener()
                                             throws javax.jms.JMSException

Gets the message consumer's MessageListener.

Specified by:

getMessageListener in interface javax.jms.MessageConsumer

Returns:

the listener for the message consumer, or null if no listener is set

Throws:

javax.jms.JMSException

setMessageListener

public void setMessageListener(javax.jms.MessageListener listener)
                        throws javax.jms.JMSException

ets the message consumer's MessageListener.

Setting the message listener to null is the equivalent of unsetting the message listener for the message consumer.

The effect of calling MessageConsumer.setMessageListener while messages are being consumed by an existing listener or the consumer is being used to consume messages synchronously is undefined.

Specified by:

setMessageListener in interface javax.jms.MessageConsumer

Parameters:

listener - the listener to which the messages are to be delivered

Throws:

javax.jms.JMSException

getMessageSelector

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

Gets this message consumer's message selector expression.

Specified by:

getMessageSelector in interface javax.jms.MessageConsumer

Returns:

this message consumer's message selector, or null if no message selector exists for the message consumer (that is, if the message selector was not set or was set to null or the empty string)

Throws:

javax.jms.JMSException

receive

public javax.jms.Message receive()
                          throws javax.jms.JMSException

Receives the next message produced for this message consumer. If no message is available, this call will block until a message can be received.

This call blocks indefinitely until a message is produced or until this message consumer is closed.

If this receive is done within a transaction, the consumer retains the message until the transaction commits.

Specified by:

receive in interface javax.jms.MessageConsumer

Returns:

the next message produced for this message consumer, or null if this message consumer is concurrently closed

Throws:

javax.jms.JMSException

receive

public javax.jms.Message receive(long timeout)
                          throws javax.jms.JMSException

Receives the next message that arrives within the specified timeout interval.

This call blocks until a message arrives, the timeout expires, or this message consumer is closed. A timeout of zero never expires, and the call blocks indefinitely.

Specified by:

receive in interface javax.jms.MessageConsumer

Parameters:

timeout - the timeout value (in milliseconds)

Returns:

the next message produced for this message consumer, or null if the timeout expires or this message consumer is concurrently closed

Throws:

javax.jms.JMSException

receiveNoWait

public javax.jms.Message receiveNoWait()
                                throws javax.jms.JMSException

Receives the next message if one is immediately available.Do not wait for a message to be recevied.

Specified by:

receiveNoWait in interface javax.jms.MessageConsumer

Returns:

the next message produced for this message consumer, or null if one is not available

Throws:

javax.jms.JMSException

close

public void close()
           throws javax.jms.JMSException

Closes the message consumer.

Since a provider may allocate some resources on behalf of a MessageConsumer outside the Java virtual machine, clients should close them when they are not needed. Relying on garbage collection to eventually reclaim these resources may not be timely enough.

This call blocks until a receive or message listener in progress has completed. A blocked message consumer receive call

Specified by:

close in interface javax.jms.MessageConsumer

Throws:

javax.jms.JMSException

isClosed

public boolean isClosed()

Indicates the status of this message consumer.

Returns:

true if the message consumer is closed