mvc项目定时任务5分钟取数据库数据保存到map,实现缓存防止频繁交互sql

雨点打透心脏的1/2处 2021-12-15 03:11 139阅读 0赞

**第一:**  
public class ManagerListener implements ServletContextListener \{

public void contextDestroyed(ServletContextEvent arg0) {
    }
    
    public void contextInitialized(ServletContextEvent sce) {
    	ApplicationContext ctx = WebApplicationContextUtils
    			.getRequiredWebApplicationContext(sce.getServletContext());
    	SyncThread syncThread = new SyncThread();// 需要执行的线程
    	Thread thread = new Thread(syncThread);// 开启一个线程
    	thread.start();// 线程执行
    	System.out.println("监听器服务器起来");
    }

**第二:**  
@Component  
public class SyncThread implements Runnable,ApplicationContextAware \{  
private Logger logger = LoggerFactory.getLogger(SyncThread.class);  
public static ApplicationContext applicationContext;// 获取spring上下文

public void run() {
    	// 通过上下文获取产线信息service实体bean
    				SysConfigService sysConfigService = (SysConfigService) applicationContext
    						.getBean(SysConfigService.class);
    	System.out.println("--------------ddshopRunServices SysConfig 启动-------------");
    	ConcurrentHashMap< String,String> acountMap = new ConcurrentHashMap<String, String>();
    	String keys="ceshiKey";
    	int count=1;
    	while (true) {
    		try {
    			if(count ==1){
    				count = 2;
    			}else{
    				Thread.sleep(300*1000);
    			}
    			
    			//获取到sys-config表的所有key值
    				SysConfig syscon=sysConfigService.getSysConfigByKey(keys);
    				//syscon为null  抛出异常了
    				System.out.println(syscon.getValue());
    			if(syscon.getValue()!=null){				
    				String s2 = syscon.getValue().substring(1);
    				String s3=s2.substring(0,s2.length() - 1);
    				String[] str=s3.split(",");
    				for(int i=0;i<str.length;i++){
    					//获取到了sys-Config表的(2,6)
    					if (Constants.warnAccountMap == null
    							|| Constants.warnAccountMap.size() <= 0) {
    						acountMap.put(str[i],str[i]);
    						Constants.warnAccountMap = acountMap;
    					} else {
    						acountMap = Constants.warnAccountMap;
    						if (acountMap.get(str[i]) == null) {
    							acountMap.put(str[i], str[i]);
    							Constants.warnAccountMap = acountMap;
    						}
    					}
    				}
    					
    				//	System.out.println("accountMap"+acountMap);
    					//acountMap存着我在sys-Config表里取出的(4.6)办事处测试的key			
    		}
    			
    		} catch (Exception e) {
    			e.printStackTrace();
    		}
    	}
    }

**//实现注入**  
@Override  
public void setApplicationContext(ApplicationContext arg0)  
throws BeansException \{  
SyncThread.applicationContext=arg0;

}

\}  
**第三:spring-context.xml增加配置**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzczNjY5Mg_size_16_color_FFFFFF_t_70]  
**context:annotation-config</context:annotation-config>  
task:annotation-driven/  
<context:component-scan base-package=“com.sigmatrix.sc.timer”></context:component-scan>**  
**web.xml增加监听器  
< listener>  
com.sigmatrix.sc.timer.ManagerListener  
< /listener>**

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MzczNjY5Mg_size_16_color_FFFFFF_t_70]: /images/20211214/6a6df28b14794e198a39942ad3abf222.png