MOM初窥：AcitveMQ HelloWorld

AcitveMQ是Apache出品，最流行的，能力强劲的开源消息总线，它是一个完全支持JMS1.1和J2EE 1.4规范的JMS Provider实现。

AcitveMQ的安装

官网下载地址：http://activemq.apache.org/download-archives.html
由于我是在Windows系统下学习AcitveMQ，所以我下载的是：apache-activemq-5.6.0-bin.zip，下载好进行解压缩，目录如下：

AcitveMQ的启动

在解压得到的bin目录中包含一个名为activemq.bat的脚本，直接运行这个脚本就可以启动一个broker，启动之前别忘了需先配置好%JAVA_HOME%环境变量。
AcitveMQ程序内部利用jetty容器部署了一个web管理界面，默认服务启动地址：http://127.0.0.1:8161/admin/
若要开启管理后台登录密码验证，可按以下步骤进行配置。
修改jetty服务器的配置文件，apache-activemq-5.6.0\conf\jetty.xml，需将"authenticate"属性设置为"true"。

    <bean id="securityConstraint" class="org.eclipse.jetty.util.security.Constraint">        <property name="name" value="BASIC" />        <property name="roles" value="admin" />        <property name="authenticate" value="true" />    </bean>

再修改管理后台的登录用户名密码配置文件，apache-activemq-5.6.0\conf\jetty-realm.properties。

## ---------------------------------------------------------------------------## 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.## ---------------------------------------------------------------------------# Defines users that can access the web (console, demo, etc.)# username: password [,rolename ...]admin: admin, admin

温馨提示：windows操作系统下，若开启Internet connection share(ICS)服务会占用61616端口，会导致ActiveMQ无法启动。

工程搭建

搭建ActiveMQ工程很简单，只需要创建一个Java project，并将ActiveMQ安装根目录下的 activemq-all-5.6.0.jar 包添加到项目的构建路径中，创建好的activeMQ_HelloWorld工程目录层级如下。

先创建生产者ActiveMQProducer，其完整代码如下。

package com.pengjunlee.activemq;import javax.jms.Connection;import javax.jms.ConnectionFactory;import javax.jms.DeliveryMode;import javax.jms.Destination;import javax.jms.MessageProducer;import javax.jms.Session;import javax.jms.TextMessage;import org.apache.activemq.ActiveMQConnectionFactory;public class ActiveMQProducer {public static void main(String[] args) throws Exception {// 第一步：创建ConnectionFactory，需要指定用户名、密码、以及要连接的地址ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(ActiveMQConnectionFactory.DEFAULT_USER,ActiveMQConnectionFactory.DEFAULT_PASSWORD,"tcp://localhost:61616");// 第二步：利用ConnectionFactory创建一个Connection连接，并且调用Connection的start()方法开启连接Connection connection = connectionFactory.createConnection();connection.start();// 第三步：通过Connection对象创建Session会话（上下文环境对象），用于接收消息// createSession的两个参数:(是否启用事务，消息确认模式)Session session = connection.createSession(Boolean.FALSE,Session.AUTO_ACKNOWLEDGE);// 第四步：通过Session创建Destination对象,目的地指的是生产消息的目标和消费消息的来源// 在PTP模式中，Destination被称作Queue队列，在Pub/Sub模式中，Destination被称作Topic主题Destination destination = session.createQueue("queue1");// 第五步：通过Session对象创建消息生产者和消息消费者（MessageProducer/MessageConsumer）MessageProducer messageProducer = session.createProducer(destination);// 第六步：利用messageProducer的setDeliveryMode()方法设置消息是否需要持久化messageProducer.setDeliveryMode(DeliveryMode.NON_PERSISTENT);// 第七步：通过Session创建Message消息TextMessage textMessage = session.createTextMessage("this is a activeMQ Message!");// 第八步：调用MessageProducer的send()方法发送消息messageProducer.send(textMessage);// 第九步：关闭连接，释放资源if (connection != null) {connection.close();}}}

运行ActiveMQProducer，登录http://127.0.0.1:8161/admin/管理后台，其队列信息如下。

再创建消息消费者ActiveMQConsumer，其完整代码如下。

package com.pengjunlee.activemq;import javax.jms.Connection;import javax.jms.ConnectionFactory;import javax.jms.Destination;import javax.jms.JMSException;import javax.jms.MessageConsumer;import javax.jms.Session;import javax.jms.TextMessage;import org.apache.activemq.ActiveMQConnectionFactory;public class ActiveMQConsumer {public static void main(String[] args) throws JMSException {// 第一步：创建ConnectionFactory，需要指定用户名、密码、以及要连接的地址ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(ActiveMQConnectionFactory.DEFAULT_USER,ActiveMQConnectionFactory.DEFAULT_PASSWORD,"tcp://localhost:61616");// 第二步：利用ConnectionFactory创建一个Connection连接，并且调用Connection的start()方法开启连接Connection connection = connectionFactory.createConnection();connection.start();// 第三步：通过Connection对象创建Session会话（上下文环境对象），用于接收消息// createSession的两个参数:(是否启用事务，消息确认模式)Session session = connection.createSession(Boolean.FALSE,Session.AUTO_ACKNOWLEDGE);// 第四步：通过Session创建Destination对象,目的地指的是生产消息的目标和消费消息的来源// 在PTP模式中，Destination被称作Queue队列，在Pub/Sub模式中，Destination被称作Topic主题Destination destination = session.createQueue("queue1");// 第五步：通过Session对象创建消息生产者和消息消费者（MessageConsumer/MessageConsumer）MessageConsumer messageConsumer = session.createConsumer(destination);// 第六步：调用MessageConsumer的receive()方法获取消息TextMessage textMessage = (TextMessage) messageConsumer.receive();System.out.println(textMessage.getText());// 第七步：关闭连接，释放资源if (connection != null) {connection.close();}}}

运行ActiveMQConsumer，登录后台再次查看队列信息。

ConnectionFactory连接密码认证

ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(ActiveMQConnectionFactory.DEFAULT_USER,ActiveMQConnectionFactory.DEFAULT_PASSWORD,"tcp://localhost:61616");

在new ActiveMQConnectionFactory时若要开启登录密码验证，可按以下步骤进行配置。

修改apache-activemq-5.6.0\conf\activemq.xml，在<systemUsage>节点前面添加如下配置。

<plugins>              <simpleAuthenticationPlugin>                  <users>                      <authenticationUser username="${activemq.username}" password="${activemq.password}" groups="users,admins"/>                  </users>              </simpleAuthenticationPlugin>           </plugins>            <!--            The systemUsage controls the maximum amount of space the broker will            use before slowing down producers. For more information, see:            http://activemq.apache.org/producer-flow-control.html            If using ActiveMQ embedded - the following limits could safely be used:        <systemUsage>            <systemUsage>                <memoryUsage>                    <memoryUsage limit="20 mb"/>                </memoryUsage>                <storeUsage>                    <storeUsage limit="1 gb"/>                </storeUsage>                <tempUsage>                    <tempUsage limit="100 mb"/>                </tempUsage>            </systemUsage>        </systemUsage>        -->

在apache-activemq-5.6.0\conf\credentials.properties文件中指定用户名和密码。

## ---------------------------------------------------------------------------## 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.## ---------------------------------------------------------------------------# Defines credentials that will be used by components (like web console) to access the brokeractivemq.username=activeMQactivemq.password=123456guest.password=password

在new ActiveMQConnectionFactory时需指定用户名和密码。

ConnectionFactory connectionFactory = new ActiveMQConnectionFactory("activeMQ","123456","tcp://localhost:61616");