看到这个标题,相信不少人会感到疑惑,回忆你们自己的场景会发现,在Spring的项目中很少有使用多线程处理任务的,没错,大多数时候我们都是使用Spring MVC开发的web项目,默认的Controller,Service,Dao组件的作用域都是单实例,无状态,然后被并发多线程调用,那么如果我想使用多线程处理任务,该如何做呢?
比如如下场景:
使用spring-boot开发一个监控的项目,每个被监控的业务(可能是一个数据库表或者是一个pid进程)都会单独运行在一个线程中,有自己配置的参数,总结起来就是:
(1)多实例(多个业务,每个业务相互隔离互不影响)
(2)有状态(每个业务,都有自己的配置参数)
如果是非spring-boot项目,实现起来可能会相对简单点,直接new多线程启动,然后传入不同的参数类即可,在spring的项目中,由于Bean对象是spring容器管理的,你直接new出来的对象是没法使用的,就算你能new成功,但是bean里面依赖的其他组件比如Dao,是没法初始化的,因为你饶过了spring,默认的spring初始化一个类时,其相关依赖的组件都会被初始化,但是自己new出来的类,是不具备这种功能的,所以我们需要通过spring来获取我们自己的线程类,那么如何通过spring获取类实例呢,需要定义如下的一个类来获取SpringContext上下文:
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/** * Created by Administrator on 2016/8/18. * 设置Sping的上下文 */ @Component public class ApplicationContextProvider implements ApplicationContextAware { private static ApplicationContext context; private ApplicationContextProvider(){} @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { context = applicationContext; } public static <T> T getBean(String name,Class<T> aClass){ return context.getBean(name,aClass); } } |
然后定义我们的自己的线程类,注意此类是原型作用域,不能是默认的单例:
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@Component ( "mTask" ) @Scope ( "prototype" ) public class MoniotrTask extends Thread { final static Logger logger= LoggerFactory.getLogger(MoniotrTask. class ); //参数封装 private Monitor monitor; public void setMonitor(Monitor monitor) { this .monitor = monitor; } @Resource (name = "greaterDaoImpl" ) private RuleDao greaterDaoImpl; @Override public void run() { logger.info( "线程:" +Thread.currentThread().getName()+ "运行中....." ); } } |
写个测试例子,测试下使用SpringContext获取Bean,查看是否是多实例:
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/** * Created by Administrator on 2016/8/18. */ @RunWith (SpringJUnit4ClassRunner. class ) public class SpingContextTest { @Test public void show() throws Exception{ MoniotrTask m1= ApplicationContextProvider.getBean( "mTask" , MoniotrTask. class ); MoniotrTask m2=ApplicationContextProvider.getBean( "mTask" , MoniotrTask. class ); MoniotrTask m3=ApplicationContextProvider.getBean( "mTask" , MoniotrTask. class ); System.out.println(m1+ " => " +m1.greaterDaoImpl); System.out.println(m2+ " => " +m2.greaterDaoImpl); System.out.println(m3+ " => " +m3.greaterDaoImpl); } } |
运行结果如下:
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[ INFO ] [2016-08-25 17:36:34] com.test.tools.SpingContextTest [57] - Started SpingContextTest in 2.902 seconds (JVM running for 4.196) 2016-08-25 17:36:34.842 INFO 8312 --- [ main] com.test.tools.SpingContextTest : Started SpingContextTest in 2.902 seconds (JVM running for 4.196) Thread[Thread-2,5,main] => com.xuele.bigdata.xalert.dao.rule.impl.GreaterDaoImpl@285f38f6 Thread[Thread-3,5,main] => com.xuele.bigdata.xalert.dao.rule.impl.GreaterDaoImpl@285f38f6 Thread[Thread-4,5,main] => com.xuele.bigdata.xalert.dao.rule.impl.GreaterDaoImpl@285f38f6 |
可以看到我们的监控类是多实例的,它里面的Dao是单实例的,这样以来我们就可以在spring中使用多线程处理我们的任务了。
如何启动我们的多线程任务类,可以专门定义一个组件类启动也可以在启动Spring的main方法中启动,下面看下,如何定义组件启动:
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@Component public class StartTask { final static Logger logger= LoggerFactory.getLogger(StartTask. class ); //定义在构造方法完毕后,执行这个初始化方法 @PostConstruct public void init(){ final List<Monitor> list = ParseRuleUtils.parseRules(); logger.info( "监控任务的总Task数:{}" ,list.size()); for ( int i= 0 ;i<list.size();i++) { MoniotrTask moniotrTask= ApplicationContextProvider.getBean( "mTask" , MoniotrTask. class ); moniotrTask.setMonitor(list.get(i)); moniotrTask.start(); logger.info( "第{}个监控task: {}启动 !" ,(i+ 1 ),list.get(i).getName()); } } } |
最后备忘下logback.xml,里面可以配置相对和绝对的日志文件路径:
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<!-- Logback configuration. See http://logback.qos.ch/manual/index.html --> < configuration scan = "true" scanPeriod = "10 seconds" > <!-- Simple file output --> < appender name = "FILE" class = "ch.qos.logback.core.rolling.RollingFileAppender" > <!--<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">--> <!-- encoder defaults to ch.qos.logback.classic.encoder.PatternLayoutEncoder --> < encoder > < pattern > [ %-5level] [%date{yyyy-MM-dd HH:mm:ss}] %logger{96} [%line] - %msg%n </ pattern > < charset >UTF-8</ charset > <!-- 此处设置字符集 --> </ encoder > < rollingPolicy class = "ch.qos.logback.core.rolling.TimeBasedRollingPolicy" > <!-- rollover daily 配置日志所生成的目录以及生成文件名的规则,默认是相对路径 --> < fileNamePattern >logs/xalert-%d{yyyy-MM-dd}.%i.log</ fileNamePattern > <!--<property name="logDir" value="E:/testlog" />--> <!--绝对路径定义--> <!--<fileNamePattern>${logDir}/logs/xalert-%d{yyyy-MM-dd}.%i.log</fileNamePattern>--> < timeBasedFileNamingAndTriggeringPolicy class = "ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP" > <!-- or whenever the file size reaches 64 MB --> < maxFileSize >64 MB</ maxFileSize > </ timeBasedFileNamingAndTriggeringPolicy > </ rollingPolicy > < filter class = "ch.qos.logback.classic.filter.ThresholdFilter" > < level >DEBUG</ level > </ filter > <!-- Safely log to the same file from multiple JVMs. Degrades performance! --> < prudent >true</ prudent > </ appender > <!-- Console output --> < appender name = "STDOUT" class = "ch.qos.logback.core.ConsoleAppender" > <!-- encoder defaults to ch.qos.logback.classic.encoder.PatternLayoutEncoder --> < encoder > < pattern > [ %-5level] [%date{yyyy-MM-dd HH:mm:ss}] %logger{96} [%line] - %msg%n </ pattern > < charset >UTF-8</ charset > <!-- 此处设置字符集 --> </ encoder > <!-- Only log level WARN and above --> < filter class = "ch.qos.logback.classic.filter.ThresholdFilter" > < level >INFO</ level > </ filter > </ appender > <!-- Enable FILE and STDOUT appenders for all log messages. By default, only log at level INFO and above. --> < root level = "INFO" > < appender-ref ref = "STDOUT" /> < appender-ref ref = "FILE" /> </ root > <!-- For loggers in the these namespaces, log at all levels. --> < logger name = "pedestal" level = "ALL" /> < logger name = "hammock-cafe" level = "ALL" /> < logger name = "user" level = "ALL" /> < include resource = "org/springframework/boot/logging/logback/base.xml" /> < jmxConfigurator /> </ configuration > |
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。
原文链接:http://www.cnblogs.com/qindongliang/p/5808145.html