kill -9 pid ???
kill可将指定的信息送至程序。预设的信息为SIGTERM(15),可将指定程序终止。若仍无奈终止该程序,可应用SIGKILL(9)信息尝试强制删除程序。程序或工作的编号可利用ps指令或jobs指令查看。
讲的这个简单,简略点来说就是用来杀死linux中的过程,啥?你问我啥是过程?请自行百度。
我置信很多人都用过kill -9 pid 这个命令,彻底杀死过程的意思,个别状况咱们应用它没有下面问题,然而在咱们我的项目中应用它就有可能存在致命的问题。
kill -9 pid 带来的问题
因为kill -9 属于暴力删除,所以会给程序带来比较严重的结果,那到底会带来什么结果呢?
举个栗子:转账性能,再给两个账户进行加钱扣钱的时候忽然断电了?这个时候会产生什么事件?对于InnoDB存储引擎来说,没有什么损失,因为它反对事务,然而对于MyISAM引擎来说那几乎就是劫难,为什么?如果给A账户扣了钱,当初须要将B账户加钱,这个时候停电了,就会造成,A的钱被扣了,然而B没有拿到这笔钱,这在生产环境是相对不容许的,kill -9 相当于忽然断电的成果。
当然了,像转账这种,必定不是应用MyISAM引擎,然而现在分布式火了起来,跨服务转账曾经是很平时的事件,这种时候如果应用kill -9 去进行服务,那就不是你的事务能保证数据的准确性了,这个时候你可能会想到分布式事务,这个世界上没有相对的平安零碎或者架构,分布式事务也是一样,他也会存在问题,概率很小,如果一旦产生,损失有可能是无法弥补的,所以肯定不能应用kill -9 去进行服务,因为你不晓得他会造成什么结果。
在MyISAM引擎中体现的更显著,比方用户的信息由两张表保护,管理员批改用户信息的时候须要批改两张表,但因为你的kill -9 暴力完结我的项目,导致只批改胜利了一张表,这也会导致数据的不一致性,这是小事,因为大不了再批改一次,然而金钱、合同这些重要的信息如果因为你的暴力删除导致错乱,我感觉可能比删库跑路还重大,至多删库还能复原,你这个都不晓得错在哪里。
那咱们应该怎么完结我的项目呢?
其实java给咱们提供了完结我的项目的性能,比方:tomcat能够应用shutdown.bat/shutdown.sh进行优雅完结。
什么叫优雅完结?
第一步:进行接管申请和外部线程。 第二步:判断是否有线程正在执行。 第三步:期待正在执行的线程执行结束。 第四步:进行容器。
以上四步才是失常的完结流程,那springboot怎么失常完结服务呢?上面我介绍几种失常完结服务的计划,请拿好小本本做好笔记。
优雅完结服务
kill -15 pid
这种形式也会比拟优雅的完结过程(我的项目),应用他的时候须要谨慎,为什么呢?咱们来看个例子
我写了一个一般的controller办法做测试
@GetMapping(value = "/test") public String test(){ log.info("test --- start"); try { Thread.sleep(100000); } catch (InterruptedException e) { e.printStackTrace(); } log.info("test --- end"); return "test"; }
代码很简略,打印:test — start之后让让程序休眠100秒,而后再打印:test — end,在线程休眠中咱们应用kill -15 pid来完结这个过程,你们猜 test — end会被打印吗?
application.yml server: port: 9988
启动我的项目
sudo mvn spring-boot:run
这是maven启动springboot我的项目的形式
看到这个就代表我的项目启动成了
找到我的项目的过程id
sudo ps -ef |grep shutdown
这个就是我的项目的过程号,接下来咱们先测试test接口,让线程进入休眠状态,而后再应用kill -15 14086进行我的项目
sudo curl 127.0.0.1:9988/test
回到我的项目日志
咱们发现申请曾经达到服务,并且线程曾经胜利进入休眠,当初咱们kill -15 14086完结过程
sudo kill -15 14086
回到日志
2020-04-24 10:53:14.939 INFO 14086 --- [nio-9988-exec-1] com.ymy.controller.TestController : test --- start 2020-04-24 10:54:02.450 INFO 14086 --- [extShutdownHook] o.s.s.concurrent.ThreadPoolTaskExecutor : Shutting down ExecutorService 'applicationTaskExecutor' java.lang.InterruptedException: sleep interrupted at java.lang.Thread.sleep(Native Method) at com.ymy.controller.TestController.test(TestController.java:26) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879) at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:109) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1594) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:748) 2020-04-24 10:54:04.574 INFO 14086 --- [nio-9988-exec-1] com.ymy.controller.TestController : test --- end 2020-04-24 10:54:04.610 ERROR 14086 --- [nio-9988-exec-1] o.s.web.servlet.HandlerExecutionChain : HandlerInterceptor.afterCompletion threw exception java.lang.NullPointerException: null at org.springframework.boot.actuate.metrics.web.servlet.LongTaskTimingHandlerInterceptor.stopLongTaskTimers(LongTaskTimingHandlerInterceptor.java:123) ~[spring-boot-actuator-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.boot.actuate.metrics.web.servlet.LongTaskTimingHandlerInterceptor.afterCompletion(LongTaskTimingHandlerInterceptor.java:79) ~[spring-boot-actuator-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.web.servlet.HandlerExecutionChain.triggerAfterCompletion(HandlerExecutionChain.java:179) ~[spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.servlet.DispatcherServlet.triggerAfterCompletion(DispatcherServlet.java:1427) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1060) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) [spring-webmvc-5.2.5.RELEASE.jar:5.2.5.RELEASE] at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) [tomcat-embed-websocket-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:109) [spring-boot-actuator-2.2.6.RELEASE.jar:2.2.6.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) [spring-web-5.2.5.RELEASE.jar:5.2.5.RELEASE] at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:373) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1594) [tomcat-embed-core-9.0.33.jar:9.0.33] at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.33.jar:9.0.33] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_242] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_242] at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.33.jar:9.0.33] at java.lang.Thread.run(Thread.java:748) [na:1.8.0_242]
竟然报错了,然而test — end是打印进去了,为什么会报错呢?这就和sleep这个办法无关了,在线程休眠期间,当调用线程的interrupt办法的时候会导致sleep抛出异样,这里很显著就是kill -15 这个命令会让程序马上调用线程的interrupt办法,目标是为了让线程进行,尽管让线程进行,但线程什么时候进行还是线程本人说的算,这就是为什么咱们还能看到:test — end的起因。
ConfigurableApplicationContext colse
咱们先看怎么实现
package com.ymy.controller; import lombok.extern.slf4j.Slf4j; import org.springframework.beans.BeansException; import org.springframework.context.ApplicationContext; import org.springframework.context.ApplicationContextAware; import org.springframework.context.ConfigurableApplicationContext; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RestController; @RestController @Slf4j public class TestController implements ApplicationContextAware { private ApplicationContext context; @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { this.context = applicationContext; } @GetMapping(value = "/test") public String test(){ log.info("test --- start"); try { Thread.sleep(100000); } catch (InterruptedException e) { e.printStackTrace(); } log.info("test --- end"); return "test"; } /** * 停机 */ @PostMapping(value = "shutdown") public void shutdown(){ ConfigurableApplicationContext cyx = (ConfigurableApplicationContext) context; cyx.close(); } }
重点在:cyx.close();,为什么他能进行springboot我的项目呢?请看源码
public void close() { synchronized(this.startupShutdownMonitor) { this.doClose(); if (this.shutdownHook != null) { try { Runtime.getRuntime().removeShutdownHook(this.shutdownHook); } catch (IllegalStateException var4) { } } } }
程序在启动的时候向jvm注册了一个敞开钩子,咱们在执行colse办法的时候会删除这个敞开钩子,jvm就会晓得这是须要进行服务。
咱们看测试后果
很显著,他也触发了线程的interrupt办法导致线程报错,原理和kill -15差不多。
actuator
这种形式是通过引入依赖的形式进行服务,actuator提供了很多接口,比方健康检查,根本信息等等,咱们也能够应用他来优雅的停机。
引入依赖
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-actuator</artifactId> </dependency>
application.yml
server: port: 9988 management: endpoints: web: exposure: include: shutdown endpoint: shutdown: enabled: true server: port: 8888
我这里对actuator的接口从新给定了一个接口,这样可进步安全性,上面咱们来测试一下
@RequestMapping(value = "/test",method = RequestMethod.GET) public String test(){ System.out.println("test --- start"); try { Thread.sleep(10000); } catch (InterruptedException e) { e.printStackTrace(); } System.out.println("test --- end"); return "hello"; }
在申请test途中进行服务
咱们发现发送进行服务申请之后还给咱们返回了提示信息,很人性化,咱们看看控制台
test — end被执行了,不过在进行线程池的时候还是调用了线程的interrupt办法,导致sleep报错,这三种形式都能够比拟优雅的进行springboot服务,如果我我的项目中存在线程休眠,我心愿10秒当前再进行服务能够吗?必定是能够的,咱们只须要略微做点批改就能够了。
- 1.新增进行springboot服务类:ElegantShutdownConfig.java
package com.ymy.config; import org.apache.catalina.connector.Connector; import org.springframework.boot.web.embedded.tomcat.TomcatConnectorCustomizer; import org.springframework.context.ApplicationListener; import org.springframework.context.event.ContextClosedEvent; import java.util.concurrent.Executor; import java.util.concurrent.ThreadPoolExecutor; import java.util.concurrent.TimeUnit; public class ElegantShutdownConfig implements TomcatConnectorCustomizer, ApplicationListener<ContextClosedEvent> { private volatile Connector connector; private final int waitTime = 10; @Override public void customize(Connector connector) { this.connector = connector; } @Override public void onApplicationEvent(ContextClosedEvent event) { connector.pause(); Executor executor = connector.getProtocolHandler().getExecutor(); if (executor instanceof ThreadPoolExecutor) { try { ThreadPoolExecutor threadPoolExecutor = (ThreadPoolExecutor) executor; threadPoolExecutor.shutdown(); if (!threadPoolExecutor.awaitTermination(waitTime, TimeUnit.SECONDS)) { System.out.println("请尝试暴力敞开"); } } catch (InterruptedException ex) { System.out.println("异样了"); Thread.currentThread().interrupt(); } } } }
- 2.在启动类中退出bean
package com.ymy; import com.ymy.config.ElegantShutdownConfig; import lombok.extern.slf4j.Slf4j; import org.apache.catalina.connector.Connector; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.boot.web.embedded.tomcat.TomcatConnectorCustomizer; import org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory; import org.springframework.boot.web.servlet.server.ServletWebServerFactory; import org.springframework.context.ApplicationListener; import org.springframework.context.ConfigurableApplicationContext; import org.springframework.context.annotation.Bean; import org.springframework.context.event.ContextClosedEvent; import java.util.concurrent.Executor; import java.util.concurrent.ThreadPoolExecutor; import java.util.concurrent.TimeUnit; @SpringBootApplication public class ShutdownServerApplication { public static void main(String[] args) { ConfigurableApplicationContext run = SpringApplication.run(ShutdownServerApplication.class, args); run.registerShutdownHook(); } @Bean public ElegantShutdownConfig elegantShutdownConfig() { return new ElegantShutdownConfig(); } @Bean public ServletWebServerFactory servletContainer() { TomcatServletWebServerFactory tomcat = new TomcatServletWebServerFactory(); tomcat.addConnectorCustomizers(elegantShutdownConfig()); return tomcat; } }
这样咱们就配置好了,咱们再来测试一遍,test的接口还是休眠10秒
咱们发现这次没有报错了,他是期待了一段时间之后再完结的线程池,这个工夫就是咱们在ElegantShutdownConfig类中配置的waitTime。
那可能你会有疑难了,jvm没有立刻进行,那这个时候在有申请会产生什么呢?如果敞开的时候有新的申请,服务将不在接管此申请。
数据备份操作
如果我想在服务进行的时候做点备份操作啥的,应该怎么做呢?其实很简略在你要执行的办法上增加一个注解即可:@PreDestroy
Destroy:毁灭、覆灭 pre:前缀缩写
所以合在一起的意思就是在容器进行之前执行一次,你能够在这外面做备份操作,也能够做记录停机工夫等。
新增服务进行备份工具类:DataBackupConfig.java
package com.ymy.config; import org.springframework.context.annotation.Configuration; import javax.annotation.PreDestroy; @Configuration public class DataBackupConfig { @PreDestroy public void backData(){ System.out.println("正在备份数据。。。。。。。。。。。"); } }
咱们再来测试而后打印控制台日志:
起源:https://www.gaodaima.com/qq_3322…