ACTIVEMQ Demo Guide

comparison of technical features between queue and topic

	Topic	Queue
Profile	Publish Subscribe Messaging Publish subscription message	Point-to-Point point-to-point
There is no status	Topic data is not landed by default and is stateless.	Queue data is saved as a file by default on the MQ server, such as Active MQ, which is typically stored under $amq_home\data\kr-store\data. Can also be configured as DB storage.
Integrity Assurance	There is no guarantee that every piece of data published by publisher will be accepted by subscriber.	The queue guarantees that each piece of data can be received by receiver.
Whether the message will be lost	In general, when Publisher publishes a message to a topic, only the sub that is listening to the topic address can receive the message, and if no sub is listening, the topic is lost.	Sender sends a message to the target Queue,receiver can receive the message on this queue asynchronously. Messages on the queue are not lost if they are not currently being picked up by receiver.
Message Publishing Receive Policy	A one-to-many message publishing receive policy that listens to multiple sub-topic addresses to receive messages from Publisher. Sub receives notification MQ server	One message to the receiving policy, a sender sends a message, only one receiver receives. After receiver is received, the MQ server is notified that the MQ server has deleted or otherwise acted on the messages in the queue.

The biggest difference between the topic and the queue is that the topic is in the form of a broadcast that notifies all online listeners that there is a new message, that the client without the listener will not receive the message, and that the queue notifies more than one client in the listening state in the form of a point-to-point.

Queue communication:

Message provider:

 public static void Main (string[] args) throws JMSException {//ConnectionFactory: Connection Factory, JMS uses it to create a connection Conn                           Ectionfactory connectionfactory = new Activemqconnectionfactory (Activemqconnection.default_user,          Activemqconnection.default_password, "tcp://localhost:61616");          JMS Client to JMS Provider connection Connection Connection = Connectionfactory.createconnection ();          Connection.start ();          Session: A thread that sends or receives a message session session = Connection.createsession (Boolean.true, Session.auto_acknowledge);          Destination: The destination of the message, to whom the message is sent.          Get session attention parameter value My-queue is the name of the query Destination Destination = Session.createqueue ("My-queue");         Destination Destination = session.createtopic ("My-topic");          MessageProducer: Message producer MessageProducer producer = Session.createproducer (destination); Set non-persistent producer.setdeliverymodE (deliverymode.non_persistent);          Send a message sendmsg (session, producer);          Session.commit ();  Connection.close ();          } public static void Sendmsg (Session session, MessageProducer producer) throws JMSException {//Create a text message          TextMessage message = Session.createtextmessage ("Hello activemq!");          A message is sent by the producer of the message producer.send;  System.out.println (Message.tostring ());  }

Message recipients:

public static void Main (string[] args) {//ConnectionFactory: Connection Factory, JMS uses it to create a connection connectionfactory connectionf        Actory;        CONNECTION:JMS client-to-JMS Provider connection Connection Connection = null;        Session: A thread that sends or receives a message session session;        Destination: The destination of the message, to whom the message is sent.        Destination Destination;        Consumer, message recipient Messageconsumer consumer; ConnectionFactory = new Activemqconnectionfactory (Activemqconnection.default_user, ActiveMQ        Connection.default_password, "tcp://localhost:61616");            try {//Construct get Connection object from factory connection = Connectionfactory.createconnection ();            Start Connection.start ();            Get operation Connection session = Connection.createsession (Boolean.false, Session.auto_acknowledge); Get session Note parameter value Xingbo.xu-queue is a server queue that must be configured in ACTIVEMQ console destination = Session.createqueue ("M Y-queUE ");            Consumer = session.createconsumer (destination);                while (true) {TextMessage message = (textmessage) consumer.receive (1000);                if (null! = message) {SYSTEM.OUT.PRINTLN ("Receive Message" + Message.gettext ());                } else {break;        }}} catch (Exception e) {e.printstacktrace ();            } finally {try {if (null! = connection) connection.close (); } catch (Throwable ignore) {}}}

　　Topic Communication:

Broadcast provider:

 private static final int send_number = 5; public static void SendMessage (Session session, MessageProducer producer) throws Exception {for (int i = 1; I <=SEND_NUMBER;            i++) {TextMessage message = session. Createtextmessage ("Messages sent by ACTIVEMQ" + i);            Send message to Destination place System.out.println ("Send message:" + "ActiveMq message sent" + i);        Producer.send (message); }} public static void Main (string[] args) {//ConnectionFactory: Connection Factory, JMS uses it to create a connection connectionfactory        ConnectionFactory;        CONNECTION:JMS client-to-JMS provider connection Connection Connection = null;        Session: A thread that sends or receives a message session session;        Destination: The destination of the message, to whom the message is sent.        Destination Destination;        MessageProducer: Message sender MessageProducer producer;        TextMessage message; Constructs the ConnectionFactory instance object, which is implemented here with the Activemq jar connectionfactory = new Activemqconnectionfactory (activemqconnEctionfactory.default_user, Activemqconnectionfactory.default_password,activemqconnectionfactory.default_broker        _bind_url);            try {//Construct get Connection object from factory connection = Connectionfactory.createconnection ();            Start Connection.start ();            Get operation Connection Session = Connection.createsession (true, Session.auto_acknowledge);             Get session Note parameter value Firsttopic is a server topic (this is the only difference compared to the sending of a queue message) Destination = Session.createtopic ("Firsttopic");            Get the message Generator "sender" producer = Session.createproducer (destination);            Set not to persist, learn here, actually according to the project decision Producer.setdeliverymode (Deliverymode.persistent);            Constructs the message, writes here to die, the project is the parameter, or the method obtains SendMessage (session, producer);        Session.commit ();        } catch (Exception e) {e.printstacktrace ();          } finally {try {if (null! = connection) connection.close ();  } catch (Throwable ignore) {}}} 

Broadcast recipient:

   Private String ThreadName;    Receivetopic (String threadname) {this.threadname = ThreadName;         public void Run () {///ConnectionFactory: Connection Factory, JMS uses it to create a connection connectionfactory connectionfactory;         CONNECTION:JMS Client to JMS provider connection Connection Connection =null;         Session: A thread that sends or receives a message session session;         Destination: The destination of the message, to whom the message is sent.         Destination Destination;         Consumer, message recipient Messageconsumer consumer; ConnectionFactory = new Activemqconnectionfactory (Activemqconnectionfactory.default_user, ActiveMQConnect         Ionfactory.default_password,activemqconnectionfactory.default_broker_bind_url);               try {//Construct get Connection object from factory connection = Connectionfactory.createconnection ();               Start Connection.start ();               Gets the operation connection, which automatically sends a successful response to the server by default session = Connection.createsession (false, Session.auto_acknowledge); Get SESsion Note The parameter value Firsttopic is a server topic destination = Session.createtopic ("Firsttopic");               Consumer = session.createconsumer (destination); while (true) {//sets the time at which the receiver receives the message, for testing purposes, this is set to 100s textmessage message = (TextMessage) c                    Onsumer. Receive (1 * 1000);                    if (null! = message) {System.out.println ("thread" +threadname+ "received message:" + message.gettext ());                    } else {continue;         }}} catch (Exception e) {e.printstacktrace ();               } finally {try {if (null! = connection) connection.close ();          } catch (Throwable ignore) {}}} public static void Main (string[] args) { Here, 3 threads are started to listen for firsttopic messages, not the same way as the queue three thread can receive the same message receivetopic receive1=new RECEIVEtopic ("Thread1");         Receivetopic receive2=new receivetopic ("Thread2");         Receivetopic receive3=new receivetopic ("Thread3");         Thread thread1=new thread (RECEIVE1);         Thread thread2=new thread (receive2);         Thread thread3=new thread (RECEIVE3);         Thread1.start ();         Thread2.start ();    Thread3.start (); }

　　If transferring Chinese: You can set the encoding format of the string new string (Msg.getbytes ("Utf-8"), "iso-8859-1"); New String (Message.tostring (). GetBytes ("Iso-8859-1"), "UTF-8");

ACTIVEMQ Demo Guide