Spring boot整合Thymelea页面静态化实现方案

Spring boot整合Thymelea页面静态化实现方案

1_需求分析

​ 如今很多大型网站为了提高并发量都会采用静态页面的方案,静态化页面可以明显提升访问速度,提高用户体验,还可以脱离数据库,减轻数据库访问上的压力.

​ 今天我们就以博客博文静态化案例来了解一下使用Thymelea页面静态化技术.

​ 当博主发布新文章时,伪装成数据库主库子库的canal(分布式数据同步中间件)收到主库发送的数据更新信息,向rabbitmq(消息中间件)中我们指定的交换机(exchange)绑定的通道(queue)发送一个包含文章唯一标识的信息,页面静态化服务监听消息类接到数据库消息和文章唯一标识,调用页面静态化接口(generateHtml(essayId))生成静态页面.

批注 2020-07-27 214852.jpg

2_实现代码

2-1.导入起步依赖,配置配置文件

canal服务

        
            com.xpand
            starter-canal
            0.0.1-SNAPSHOT
        
        
            org.springframework.amqp
            spring-rabbit
        
    

canal.client.instances.example.host=192.168.200.128 
canal.client.instances.example.port=11111
canal.client.instances.example.batchSize=1000
spring.rabbitmq.host=192.168.200.128

staticPage服务

            org.springframework.boot
            spring-boot-starter-thymeleaf
        
        
            org.springframework.boot
            spring-boot-starter-amqp
        

2-2.canal代码实现

监听类EssayListener实现

@CanalEventListener
public class EssayListener {

    @Autowired
    private RabbitTemplate rabbitTemplate;

    @ListenPoint(schema = "jianshu_essay",table = "tb_essay")//设定监听的库名和表名
    public void essay(CanalEntry.EntryType entryType,CanalEntry.RowData rowData){
        Map oldData = new HashMap<>();
        rowData.getBeforeColumnsList().forEach(c->oldData.put(c.getName(),c.getValue()));//从canal里获取更新前的数据

        Map newData = new HashMap<>();
        rowData.getAfterColumnsList().forEach(column -> newData.put(column.getName(),column.getValue()));//获取更新后的数据

        if ("0".equals(oldData.get("is_issue"))&& "1".equals(newData.get("is_issue"))){
          rabbitTemplate.convertAndSend(RbqConfig.ESSAY_ISSUE_EXCHANGE,"",newData.get("id"));
        }//判断是否是文章发布信息更新,并向rabbitmq发送消息

        if ("1".equals(oldData.get("is_issue"))&& "0".equals(newData.get("is_issue"))){
            rabbitTemplate.convertAndSend(RbqConfig.ESSAY_PULL_EXCHANGE,"",newData.get("id"));
        }//判断是否是文章下架信息更新,并发送消息
    }


}

交换机和队列声明类

@Configuration
public class RbqConfig {
    public static final String UPDATE_QUERE="update_quere";

    public static final String ESSAY_ISSUE_EXCHANGE="ESSAY_ISSUE_EXCHANGE";
    public static final String ESSAY_PULL_EXCHANGE="ESSAY_PULL_EXCHANGE";

    public static final String SEARCH_ADD_QUEUE="search_add_queue";
    public static final String SEARCH_DEL_QUEUE="search_del_queue";

    @Bean
    public Queue UPDATE_QUERE(){
        return new Queue(UPDATE_QUERE);
    }

    @Bean(SEARCH_ADD_QUEUE)
    public Queue SEARCH_ADD_QUEUE(){
        return new Queue(SEARCH_ADD_QUEUE);
    }
    @Bean(SEARCH_DEL_QUEUE)
    public Queue  SEARCH_DEL_QUEUE(){
        return new Queue(SEARCH_DEL_QUEUE);
    }

    @Bean(ESSAY_ISSUE_EXCHANGE)
    public Exchange ESSAY_ISSUE_EXCHANGE(){
        return ExchangeBuilder.fanoutExchange(ESSAY_ISSUE_EXCHANGE).durable(true).build();
    }
    @Bean(ESSAY_PULL_EXCHANGE)
    public Exchange ESSAY_PULL_EXCHANGE(){
        return ExchangeBuilder.fanoutExchange(ESSAY_PULL_EXCHANGE).durable(true).build();
    }

    @Bean
    public Binding GESSAY_ISSUE_EXCHANGE_BINDING(@Qualifier(SEARCH_ADD_QUEUE) Queue queue,@Qualifier(ESSAY_ISSUE_EXCHANGE) Exchange exchange){
        return BindingBuilder.bind(queue).to(exchange).with("").noargs();
    }

    @Bean
    public Binding ESSAY_PULL_EXCHANGE_BINDING(@Qualifier(SEARCH_DEL_QUEUE) Queue queue,@Qualifier(ESSAY_PULL_EXCHANGE) Exchange exchange){
        return BindingBuilder.bind(queue).to(exchange).with("").noargs();
    }


}

2-3.staticPage服务代码实现

消息监听类PageListener

@Component
public class PageListener {
    @Autowired
    private PageService pageService;

    @RabbitListener(queues = RbqConfig.SEARCH_ADD_QUEUE)//设置监听的消息队列
    public void receiveMessage(String id){
        System.out.println("获取页面静态化数据id"+id);

        pageService.generateHtml(id);//调用页面静态化实现接口
    }
}

页面静态接口实现类pageServiceImpl

@Service
public class PageServiceImpl implements PageService {

    @Value("${pagepath}")
    private String pagepath;

    @Autowired
    private TemplateEngine templateEngine;

    @Override
    public void generateHtml(String Id) {
        Context context = new Context();//创建用于存储文章相关信息的相关数据
        Map itemData = this.getItemData(Id);//获取文章数据
        context.setVariables(itemData);

        File file = new File(pagepath);//获取生成的静态页面存储的位置
        if (!file.exists()){
            file.mkdir();//判断如果不存在指定文件就新建
        }

        File file1 = new File(file + "/" + Id + ".html");//生成文件的名称,这里用文章唯一标识作为名称
        Writer writer = null;
        try {
            writer = new PrintWriter(file1);//定义输出流

            templateEngine.process("item",context,writer);//调用thymeleaf提供的方法生成静态页面,分别传入模板名称,页面数据,输出流
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }finally {
            try {
                writer.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}