Freemarker静态化ActiveMQ实现

Freemarker

实现商品页面静态化

ActiveMQ
使用topic模式，添加商品时
监听到消息，根据商品id
从数据库中查询商品信息，生成静态页面

注意
不从redis中获取商品信息
添加商品时，redis没有该商品信息
根据商品id，从数据库中查询商品信息

不直接传递商品信息，而是根据id，从数据库中查询
因为，不在一个项目中，静态化页面是一个独立的项目
传输数据的效率不高，修改商品信息时，也需要更新静态页面

引入ActiveMQ

<dependency>
    <groupId>org.apache.activemqgroupId>
    <artifactId>activemq-allartifactId>
dependency>

监听器

ItemAddMesssageListener
public class ItemAddMesssageListener implements MessageListener {

    @Autowired
    private ItemService itemService;
    @Autowired
    private FreeMarkerConfigurer freeMarkerConfigurer;
    @Value("${HTML_OUT_PATH}")
    private String HTML_OUT_PATH;
    @Override
    public void onMessage(Message message) {
        try {
            //从消息中取商品id
            TextMessage textMessage = (TextMessage) message;
            String strId = textMessage.getText();
            Long itemId = Long.parseLong(strId);
            //等待事务提交
            Thread.sleep(1000);
            //根据商品id查询商品信息及商品描述
            TbItem tbItem = itemService.getItemById(itemId);
            Item item = new Item(tbItem);
            TbItemDesc itemDesc = itemService.getItemDescById(itemId);
            //使用freemarker生成静态页面
            Configuration configuration = freeMarkerConfigurer.getConfiguration();
            //1.创建模板
            //2.加载模板对象
            Template template = configuration.getTemplate("item.ftl");
            //3.准备模板需要的数据
            Map data = new HashMap<>();
            data.put("item", item);
            data.put("itemDesc", itemDesc);
            //4.指定输出的目录及文件名
            Writer out = new FileWriter(new File(HTML_OUT_PATH + strId + ".html"));
            //5.生成静态页面
            template.process(data, out);
            //关闭流
            out.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

配置监听器

springmvc-activemq.xml

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
    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-4.2.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.2.xsd
    http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-4.2.xsd">

    
    <bean id="targetConnectionFactory" class="org.apache.activemq.ActiveMQConnectionFactory">
        <constructor-arg name="brokerURL" value="tcp://192.168.25.168:61616"/>
    bean>
    
    <bean id="connectionFactory" class="org.springframework.jms.connection.SingleConnectionFactory">
        <property name="targetConnectionFactory" ref="targetConnectionFactory">property>
    bean>

    <bean id="itemAddTopic" class="org.apache.activemq.command.ActiveMQTopic">
        <constructor-arg name="name" value="item-add-topic">constructor-arg>
    bean>
    <bean id="itemAddMessageListener" class="com.taotao.item.listener.ItemAddMesssageListener"/>
    <bean class="org.springframework.jms.listener.DefaultMessageListenerContainer">
        <property name="connectionFactory" ref="connectionFactory" />
        <property name="destination" ref="itemAddTopic" />
        <property name="messageListener" ref="itemAddMessageListener" />
    bean>
beans>

加载配置文件

Web.xml中配置Servlet

<servlet>
    <servlet-name>taotao-item-webservlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
    
    <init-param>
        <param-name>contextConfigLocationparam-name>
        <param-value>classpath:spring/springmvc*.xmlparam-value>
    init-param>
    <load-on-startup>1load-on-startup>
servlet>