diff options
Diffstat (limited to 'trunk/qpid/java/client/example/src/main/java/org/apache/qpid/example/subscriber/Subscriber.java')
-rw-r--r-- | trunk/qpid/java/client/example/src/main/java/org/apache/qpid/example/subscriber/Subscriber.java | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/trunk/qpid/java/client/example/src/main/java/org/apache/qpid/example/subscriber/Subscriber.java b/trunk/qpid/java/client/example/src/main/java/org/apache/qpid/example/subscriber/Subscriber.java new file mode 100644 index 0000000000..f75558299c --- /dev/null +++ b/trunk/qpid/java/client/example/src/main/java/org/apache/qpid/example/subscriber/Subscriber.java @@ -0,0 +1,182 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +package org.apache.qpid.example.subscriber; + +import org.apache.qpid.client.AMQConnectionFactory; + +import javax.jms.*; +import javax.jms.Connection; +import javax.jms.MessageConsumer; +import javax.jms.Session; +import javax.naming.InitialContext; + +import org.apache.qpid.example.shared.InitialContextHelper; +import org.slf4j.LoggerFactory; +import org.slf4j.Logger; + +/** + * Subscriber which consumes messages from a queue + */ + +public class Subscriber +{ + private static final Logger _log = LoggerFactory.getLogger(Subscriber.class); + + protected static Connection _connection; + + protected static MessageConsumer _consumer; + + protected static InitialContextHelper _contextHelper; + + protected static AMQConnectionFactory _connectionFactory; + + protected Destination _destination; + + public Subscriber() + { + try + { + //get an initial context from default properties + _contextHelper = new InitialContextHelper(null); + InitialContext ctx = _contextHelper.getInitialContext(); + + //then create a connection using the AMQConnectionFactory + _connectionFactory = (AMQConnectionFactory) ctx.lookup("local"); + + //lookup queue from context + _destination = (Destination) ctx.lookup("MyQueue"); + + } + catch (Exception e) + { + e.printStackTrace(); + _log.error("Exception", e); + } + } + + /** + * Listener class that handles messages + */ + public static class ExampleMessageListener implements MessageListener + { + private String _name; + + public ExampleMessageListener(String name) + { + _name = name; + } + + /** + * Listens for message callbacks, handles and then acknowledges them + * @param message - the message received + */ + public void onMessage(javax.jms.Message message) + { + _log.info(_name + " got message '" + message + "'"); + + try + { + //NB: Handle your message appropriately for your application here + //do some stuff + + _log.debug("Acknowledging recieved message"); + + //Now acknowledge the message to clear it from our queue + message.acknowledge(); + } + catch(JMSException j) + { + _log.error("JMSException trying to acknowledge message receipt"); + j.printStackTrace(); + } + catch(Exception e) + { + _log.error("Unexpected exception trying to handle message"); + e.printStackTrace(); + } + } + } + + /** + * Subscribes to example Queue and attaches listener + */ + public void subscribe() + { + _log.info("Starting subscription ..."); + + try + { + _connection = _connectionFactory.createConnection(); + + //Non transactional session using client acknowledgement + Session session = _connection.createSession(false, Session.CLIENT_ACKNOWLEDGE); + + //Create a consumer with a destination of our queue which will use defaults for prefetch etc + _consumer = session.createConsumer(_destination); + + //give the message listener a name of it's own + _consumer.setMessageListener(new ExampleMessageListener("MessageListener " + System.currentTimeMillis())); + + _connection.start(); + } + catch (Throwable t) + { + _log.error("Fatal error: " + t); + t.printStackTrace(); + } + + _log.info("Waiting for messages ..."); + + //wait for messages and sleep to survive failover + try + { + while(true) + { + Thread.sleep(Long.MAX_VALUE); + } + } + catch (Exception e) + { + _log.warn("Exception while Subscriber sleeping",e); + } + } + + /** + * Stop consuming and close connection + */ + public void stop() + { + try + { + _consumer.close(); + _consumer = null; + _connection.stop(); + _connection.close(); + } + catch(JMSException j) + { + _log.error("JMSException trying to Subscriber.stop: " + j.getStackTrace()); + } + } + +} + + + + |