Message selector: Filter messages whose message attributes are equal to the set conditions for consumption. The semantics are consistent with sql.
private final String selector_1 = "sex='w'"; this.consumer = session.createConsumer(destination, selector_1);
2. Asynchronous reception of
messages: Asynchronous reception of messages: When a message arrives, ActiveMQ notifies the consumer actively. You can register a MessageListener class to implement the onMessage method to monitor the delivery of messages by MQ
Example :
public class Producer {
// Create a connectionFactory factory object
private ActiveMQConnectionFactory connectionFactory;
// connection object
private Connection connection;
// session object
private Session session;
// producer
private MessageProducer producer;
public Producer() {
this.connectionFactory = new ActiveMQConnectionFactory();
try {
this.connection = connectionFactory.createConnection("fu", "fu");
this.connection.start();
//Refer to one: open the transaction, refer to the second, manually sign for receipt
this.session = connection.createSession(Boolean.TRUE, Session.CLIENT_ACKNOWLEDGE);
this.producer = session.createProducer(null);
} catch (Exception e) {
e.printStackTrace ();
}
}
public void send() throws Exception {
Destination destination = this.session.createQueue("first");
MapMessage map = this.session.createMapMessage();
//set message
map.setString("name", "zs");
map.setString("age", "40");
// set message properties
map.setStringProperty("sex", "m");
MapMessage map1 = this.session.createMapMessage();
map1.setString("name", "ls");
map1.setString("age", "20");
map1.setStringProperty("sex", "w");
MapMessage map2 = this.session.createMapMessage();
map2.setString("name", "ww");
map2.setString("age", "35");
map2.setStringProperty("sex", "w");
//Refer to the first target, refer to the second data, refer to the third non-persistence, refer to the fourth for priority, refer to the fifth failure time
this.producer.send(destination, map, DeliveryMode.PERSISTENT, 2, 1000*10);
this.producer.send(destination, map1, DeliveryMode.PERSISTENT, 2, 1000*10);
this.producer.send(destination, map2, DeliveryMode.PERSISTENT, 9, 1000*10);
// commit the transaction
this.session.commit();
//close the connection
this.connection.close();
}
public static void main(String[] args) throws Exception {
Producer p = new Producer();
p.send();
}
}
public class Comsumer {
// private final String selector_0 = "age>30";
// The message is not filtered by the message itself, but by some attributes attached to the filter
private final String selector_1 = "sex='w'";
// Create a connectionFactory factory object
private ActiveMQConnectionFactory connectionFactory;
// connection object
private Connection connection;
// session object
private Session session;
// producer
private MessageConsumer consumer;
// target address
private Destination destination;
public Comsumer() {
this.connectionFactory = new ActiveMQConnectionFactory();
try {
this.connection = connectionFactory.createConnection("fu", "fu");
this.connection.start();
this.session = connection.createSession(Boolean.TRUE, Session.CLIENT_ACKNOWLEDGE);
this.destination = this.session.createQueue("first");
// The message is not filtered by the message itself, but by some attributes attached to the filter
this.consumer = session.createConsumer(destination, selector_1);
} catch (Exception e) {
e.printStackTrace ();
}
}
public void recever() throws Exception {
// Asynchronous reception of messages: When a message arrives, ActiveMQ notifies the consumer actively, you can register a MessageListener class to implement the onMessage method to monitor the MQ delivery of messages
this.consumer.setMessageListener(new Listener());
}
class Listener implements MessageListener {
public void onMessage(Message message) {
try {
if (message instanceof TextMessage) {
} else if (message instanceof MapMessage) {
MapMessage m = (MapMessage) message;
System.out.println(m.toString());
System.out.println(m.getString("name"));
System.out.println(m.getString("age"));
// Manually sign for the message
m.acknowledge();
}
} catch (JMSException e) {
e.printStackTrace ();
}
}
}
public static void main(String[] args) throws Exception {
Comsumer c = new Comsumer();
c.recever();
}
}