ActiveMQ 的安全机制

    为了避免"只要知道本机的ip和端口，任何人都可以向queue中发送消息 或者 从queue中取消息"这种情况，
可以使用ActiveMQ的安全机制，不再使用默认的用户名和密码，而是使用自己设定的用户名和密码。
    这个可以到ActiveMQ的配置文件activemq.xml中进行配置,
    activemq.xml的路劲，例如：D:\Program Files\Java\ActiveMq\apache-activemq-5.6.0\conf 这个路径下面。

1.配置用户名和密码

配置用户名和密码只需要在 activemq.xml文件中的 <broker></broker> 标签里面加入一个 <plugins></plugins>标签即可，具体如下：

    <plugins>     
        <simpleAuthenticationPlugin>    
        <users>    
            <authenticationUser username="chen" password="chen123" groups="users,admins"/>    
        </users>    
        </simpleAuthenticationPlugin>    
    </plugins> 

整个activemq.xml文件如下：

<!--
    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.
-->
<!-- START SNIPPET: example -->
<beans
  xmlns="http://www.springframework.org/schema/beans"
  xmlns:amq="http://activemq.apache.org/schema/core"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
  http://activemq.apache.org/schema/core http://activemq.apache.org/schema/core/activemq-core.xsd">

    <!-- Allows us to use system properties as variables in this configuration file -->
    <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="locations">
            <value>file:${activemq.conf}/credentials.properties</value>
        </property>
    </bean>

    <!--
        The <broker> element is used to configure the ActiveMQ broker.
    -->
    <broker xmlns="http://activemq.apache.org/schema/core" brokerName="localhost" dataDirectory="${activemq.data}">

        <!--
            For better performances use VM cursor and small memory limit.
            For more information, see:

            http://activemq.apache.org/message-cursors.html

            Also, if your producer is "hanging", it's probably due to producer flow control.
            For more information, see:
            http://activemq.apache.org/producer-flow-control.html
        -->

        <destinationPolicy>
            <policyMap>
              <policyEntries>
                <policyEntry topic=">" producerFlowControl="true" memoryLimit="1mb">
                  <pendingSubscriberPolicy>
                    <vmCursor />
                  </pendingSubscriberPolicy>
                </policyEntry>
                <policyEntry queue=">" producerFlowControl="true" memoryLimit="1mb">
                  <!-- Use VM cursor for better latency
                       For more information, see:

                       http://activemq.apache.org/message-cursors.html

                  <pendingQueuePolicy>
                    <vmQueueCursor/>
                  </pendingQueuePolicy>
                  -->
                </policyEntry>
              </policyEntries>
            </policyMap>
        </destinationPolicy>


        <!--
            The managementContext is used to configure how ActiveMQ is exposed in
            JMX. By default, ActiveMQ uses the MBean server that is started by
            the JVM. For more information, see:

            http://activemq.apache.org/jmx.html
        -->
        <managementContext>
            <managementContext createConnector="false"/>
        </managementContext>

        <!--
            Configure message persistence for the broker. The default persistence
            mechanism is the KahaDB store (identified by the kahaDB tag).
            For more information, see:

            http://activemq.apache.org/persistence.html
        -->
        <persistenceAdapter>
            <kahaDB directory="${activemq.data}/kahadb"/>
        </persistenceAdapter>


          <!--
            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>
        -->
          <systemUsage>
            <systemUsage>
                <memoryUsage>
                    <memoryUsage limit="64 mb"/>
                </memoryUsage>
                <storeUsage>
                    <storeUsage limit="100 gb"/>
                </storeUsage>
                <tempUsage>
                    <tempUsage limit="50 gb"/>
                </tempUsage>
            </systemUsage>
        </systemUsage>

        <!--
            The transport connectors expose ActiveMQ over a given protocol to
            clients and other brokers. For more information, see:

            http://activemq.apache.org/configuring-transports.html
        -->
        <transportConnectors>
            <transportConnector name="openwire" uri="tcp://0.0.0.0:61616"/>
        </transportConnectors>


        <plugins>     
            <simpleAuthenticationPlugin>    
            <users>    
                <authenticationUser username="chen" password="chen123" groups="users,admins"/>    
            </users>    
            </simpleAuthenticationPlugin>    
        </plugins>    



    </broker>

    <!--
        Enable web consoles, REST and Ajax APIs and demos

        Take a look at ${ACTIVEMQ_HOME}/conf/jetty.xml for more details
    -->
    <import resource="jetty.xml"/>

</beans>
<!-- END SNIPPET: example -->

2.重启ActiveMQ，即重启 activemq.bat 文件。

3.在生产者(Sender)和消费者(receiver) 创建连接工厂的代码部分，修改默认的用户名和密码 为 自己设定的用户名和密码；如果不修改，则访问会报错

ConnectionFactory connectionFactory = new ActiveMQConnectionFactory(
            "chen",
            "chen123",
            "tcp://localhost:61616");