Apache Activemq 简明教程

Apache ActiveMQ - Subscriber Application

现在，让我们创建一个将从 ActiveMQ 主题接收消息的订阅者应用程序。

Create Project

使用 eclipse，选择 File → New → Maven Project 。勾选 创建简单项目（跳过原型选择），然后单击下一步。

按照以下所示输入详细信息 −

  1. groupId − com.tutorialspoint

  2. artifactId − subscriber

  3. version − 0.0.1-SNAPSHOT

  4. name − ActiveMQ Subscriber

单击“完成”按钮，将创建新项目。

pom.xml

现在，更新 pom.xml 的内容，以包含 ActiveMQ 的依赖关系。

<project xmlns="http://maven.apache.org/POM/4.0.0"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
   https://maven.apache.org/xsd/maven-4.0.0.xsd">

   <modelVersion>4.0.0</modelVersion>
   <groupId>com.tutorialspoint.activemq</groupId>
   <artifactId>subscriber</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <name>ActiveMQ Subscriber</name>
   <dependencies>
      <dependency>
         <groupId>org.apache.geronimo.specs</groupId>
         <artifactId>geronimo-jms_1.1_spec</artifactId>
         <version>1.1</version>
      </dependency>
      <dependency>
         <groupId>org.apache.qpid</groupId>
         <artifactId>qpid-jms-client</artifactId>
         <version>0.40.0</version>
      </dependency>
   </dependencies>
   <build>
      <plugins>
         <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>2.1</version>
            <configuration>
               <source>1.6</source>
               <target>1.6</target>
            </configuration>
         </plugin>
         <plugin>
            <groupId>org.fusesource.mvnplugins</groupId>
            <artifactId>maven-uberize-plugin</artifactId>
            <version>1.14</version>
            <executions>
               <execution>
                  <phase>package</phase>
                  <goals><goal>uberize</goal></goals>
               </execution>
            </executions>
         </plugin>
      </plugins>
   </build>
</project>

现在创建一个将从 ActiveMQ 队列接收消息的订阅者类。

package com.tutorialspoint.activemq;

import java.io.Console;

import javax.jms.Connection;
import javax.jms.Destination;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;

import org.apache.qpid.jms.JmsConnectionFactory;

public class Subscriber {
   public static void main(String[] args) throws Exception {
      // Create a connection to ActiveMQ JMS broker using AMQP protocol
      JmsConnectionFactory factory = new JmsConnectionFactory("amqp://localhost:5672");
      Connection connection = factory.createConnection("admin", "password");
      connection.start();

      // Create a session
      Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);

      // Create a topic
      Destination destination = session.createTopic("MyFirstTopic");

      // Create a subscriber specific to topic
      MessageConsumer subscriber = session.createConsumer(destination);

      Console c = System.console();
      String response;
      do {
         // Receive the message
         Message msg = subscriber.receive();
         response = ((TextMessage) msg).getText();

         System.out.println("Received = "+response);

      } while (!response.equalsIgnoreCase("Quit"));

      // Close the connection
      connection.close();
   }
}

订阅者类创建一个连接，启动会话，创建一个使用者，然后接收来自主题的消息（如果有）。如果该主题包含要退出的信息，则应用程序将终止，否则它将继续轮询队列以获取消息。

我们将在 ActiveMQ - Test Application 章节中多次运行此应用程序以创建多个订阅者。