0 课程地址
http://coding.imooc.com/lesson/380.html#mid=28360
1 浓缩精华
2.1，4.1，4.2
2 个人关注
2.1 initializingbean开启启动和本节两种开机启动有什么优劣
这个问题提的挺好的，我来做一些解释。首先，我们可以看一看 InitializingBean 的定义：
public interface InitializingBean { void afterPropertiesSet() throws Exception;} |
InitializingBean 接口为 bean 提供了属性初始化后的处理方法，它只包括 afterPropertiesSet 方法，凡是继承该接口的类，在 bean 的属性初始化后都会执行该方法。
但是，需要注意的是，InitializingBean 是在当前的 Bean 初始化完成之后就去执行的。而我在课程中讲到的 ApplicationRunner 和 CommandLineRunner 则是在所有的 Bean 都初始化完成之后才会去执行。所以，我们可以在 ApplicationRunner 和 CommandLineRunner 中直接注入系统中的 bean 做一些操作。
另外，InitializingBean 是 Spring 框架的接口，而 ApplicationRunner 和 CommandLineRunner 则是 SpringBoot 提供的接口。
不过，通常来说，如果开机启动的任务没有依赖，使用任何一种方式都是可行的，区别不大。
3 课程内容
3.1 课程内容
两种开机启动方式以及@Order注解的应用
4 代码演练
4.1 两种开启启动方式（ApplicationRunner和CommandRunner）（ApplicationRunner先启动）
BootApplicationRunner
package com.imooc.springboot.application.study; import lombok.extern.slf4j.Slf4j; import org.springframework.boot.ApplicationArguments; import org.springframework.boot.ApplicationRunner; import org.springframework.stereotype.Component; /** * BootApplicationRunner * * @author 魏豆豆 * @date 2021/4/4 */ @Component @Slf4j public class BootApplicationRunner implements ApplicationRunner { @Override public void run(ApplicationArguments args) throws Exception { log.info("BootApplicationRunner===========启动"); } }
BootCommandRunner
package com.imooc.springboot.application.study; import lombok.extern.slf4j.Slf4j; import org.springframework.boot.CommandLineRunner; import org.springframework.stereotype.Component; /** * BootCommandRunner * * @author 魏豆豆 * @date 2021/4/4 */ @Component @Slf4j public class BootCommandRunner implements CommandLineRunner { @Override public void run(String... args) throws Exception { log.info("============================BootCommandRunner"); } }
打印日志
. ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v2.1.4.RELEASE) 2021-04-04 08:39:37.971 INFO 32 --- [ main] c.i.s.a.SpringBootStudyApplication : Starting SpringBootStudyApplication on DESKTOP-A08HONB with PID 32 (F:\kewai\SpringCloud\laoqin\chapter_3\imooc_springboot_study\target\classes started by weijingli in F:\kewai\SpringCloud\laoqin\chapter_3\imooc_springboot_study) 2021-04-04 08:39:37.982 INFO 32 --- [ main] c.i.s.a.SpringBootStudyApplication : No active profile set, falling back to default profiles: default 2021-04-04 08:39:43.845 ERROR 32 --- [ main] o.a.catalina.core.AprLifecycleListener : An incompatible version [1.1.32] of the APR based Apache Tomcat Native library is installed, while Tomcat requires version [1.2.14] 2021-04-04 08:39:45.470 ERROR 32 --- [ main] o.a.catalina.core.AprLifecycleListener : An incompatible version [1.1.32] of the APR based Apache Tomcat Native library is installed, while Tomcat requires version [1.2.14] 2021-04-04 08:39:45.828 INFO 32 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 8081 (http) 2021-04-04 08:39:45.855 ERROR 32 --- [ main] o.a.catalina.core.AprLifecycleListener : An incompatible version [1.1.32] of the APR based Apache Tomcat Native library is installed, while Tomcat requires version [1.2.14] 2021-04-04 08:39:45.871 INFO 32 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat] 2021-04-04 08:39:45.871 INFO 32 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.17] 2021-04-04 08:39:46.403 INFO 32 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/imooc] : Initializing Spring embedded WebApplicationContext 2021-04-04 08:39:46.403 INFO 32 --- [ main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 8187 ms 2021-04-04 08:39:47.698 INFO 32 --- [ main] o.s.s.concurrent.ThreadPoolTaskExecutor : Initializing ExecutorService 'applicationTaskExecutor' 2021-04-04 08:39:48.347 INFO 32 --- [ main] o.s.s.c.ThreadPoolTaskScheduler : Initializing ExecutorService 'taskScheduler' 2021-04-04 08:39:48.385 INFO 32 --- [ main] o.s.b.a.e.web.EndpointLinksResolver : Exposing 2 endpoint(s) beneath base path '/actuator' 2021-04-04 08:39:48.649 INFO 32 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 8081 (http) with context path '/imooc' 2021-04-04 08:39:48.656 INFO 32 --- [ main] c.i.s.a.SpringBootStudyApplication : Started SpringBootStudyApplication in 13.154 seconds (JVM running for 15.812) 2021-04-04 08:39:48.692 INFO 32 --- [ main] c.i.s.a.study.BootApplicationRunner : BootApplicationRunner===========启动 2021-04-04 08:39:48.692 INFO 32 --- [ main] c.i.s.a.study.BootCommandRunner : ============================BootCommandRunner
4.2 @Order调整先后顺序
BootApplicationRunner
package com.imooc.springboot.application.study;
import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.stereotype.Component;
/**
* BootApplicationRunner
*
* @author 魏豆豆
* @date 2021/4/4
*/
@Order(2)
@Component
@Slf4j
public class BootApplicationRunner implements ApplicationRunner {
@Override
public void run(ApplicationArguments args) throws Exception {
log.info("BootApplicationRunner===========启动");
}
}
BootCommandRunner
package com.imooc.springboot.application.study;
import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.CommandLineRunner;
import org.springframework.stereotype.Component;
/**
* BootCommandRunner
*
* @author 魏豆豆
* @date 2021/4/4
*/
@Order(1)
@Component
@Slf4j
public class BootCommandRunner implements CommandLineRunner {
@Override
public void run(String... args) throws Exception {
log.info("============================BootCommandRunner");
}
}
打印日志：
2021-04-04 08:46:11.492 INFO 18544 --- [ main] c.i.s.a.study.BootCommandRunner : ============================BootCommandRunner
2021-04-04 08:46:11.492 INFO 18544 --- [ main] c.i.s.a.study.BootApplicationRunner : BootApplicationRunner===========启动
诸葛
