Springboot项目启动后执行特定方法

Springboot给我们提供了两种“开机启动”方式：ApplicationRunner和CommandLineRunner。
这两种方法提供的目的是为了满足，在项目启动的时候立刻执行某些方法。我们可以通过实现ApplicationRunner和CommandLineRunner，来实现，他们都是在SpringApplication 执行之后开始执行的。
CommandLineRunner接口可以用来接收字符串数组的命令行参数，ApplicationRunner 是使用ApplicationArguments 用来接收参数的

使用ApplicationRunner

/**
 * 项目启动执行 ApplicationRunner
 */
@Component
public class MyApplicationRunner implements ApplicationRunner {

    private static Logger log = LoggerFactory.getLogger(MyCommandLineRunner.class);

    @Override
    public void run(ApplicationArguments var1) throws Exception{
        log.info(" ApplicationRunner 项目启动，开始执行...");

    }
}

使用 CommandLineRunner

/**
 * 项目启动执行 CommandLineRunner
 */
@Component
public class MyCommandLineRunner  implements CommandLineRunner {

    private static Logger log = LoggerFactory.getLogger(MyCommandLineRunner.class);
    @Override
    public void run(String... var1) throws Exception {
        log.info(" CommandLineRunner 项目启动，开始执行...");
    }
}

项目启动测试

2022-08-17 20:25:07.723  INFO 13704 --- [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8089 (https) with context path '/gc'
2022-08-17 20:25:07.763  INFO 13704 --- [  restartedMain] com.chat.gc.GcChatWebrtcApplication      : Started GcChatWebrtcApplication in 3.862 seconds (JVM running for 152.095)
2022-08-17 20:25:07.765  INFO 13704 --- [  restartedMain] com.chat.gc.config.MyCommandLineRunner   :  ApplicationRunner 项目启动，开始执行...
2022-08-17 20:25:07.765  INFO 13704 --- [  restartedMain] com.chat.gc.config.MyCommandLineRunner   :  CommandLineRunner 项目启动，开始执行...
2022-08-17 20:25:07.901  INFO 13704 --- [  restartedMain] .ConditionEvaluationDeltaLoggingListener : Condition evaluation unchanged

指定启动方法执行的顺序

如果想要指定启动方法执行的顺序，可以通过实现org.springframework.core.Ordered接口或者使用org.springframework.core.annotation.Order注解来实现。
以ApplicationRunner 为例来分别实现

Ordered接口：

    /**
 * 项目启动执行 ApplicationRunner
 */
@Component
public class MyApplicationRunner implements ApplicationRunner, Ordered {

    private static Logger log = LoggerFactory.getLogger(MyCommandLineRunner.class);

    @Override
    public void run(ApplicationArguments var1) throws Exception{
        log.info(" ApplicationRunner 项目启动，开始执行...");
    }

    @Override
    public int getOrder() {
        return 1;
    }
}

项目启动测试

2022-08-17 20:30:24.063  INFO 7460 --- [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8089 (https) with context path '/gc'
2022-08-17 20:30:24.069  INFO 7460 --- [  restartedMain] com.chat.gc.GcChatWebrtcApplication      : Started GcChatWebrtcApplication in 15.202 seconds (JVM running for 20.388)
2022-08-17 20:30:24.071  INFO 7460 --- [  restartedMain] com.chat.gc.config.MyCommandLineRunner   :  ApplicationRunner 项目启动，开始执行...
2022-08-17 20:30:24.071  INFO 7460 --- [  restartedMain] com.chat.gc.config.MyCommandLineRunner   :  CommandLineRunner 项目启动，开始执行...

Order注解实现方式：

/**
 * 项目启动执行 CommandLineRunner
 */
@Order(value = 2)
@Component
public class MyCommandLineRunner  implements CommandLineRunner {

    private static Logger log = LoggerFactory.getLogger(MyCommandLineRunner.class);
    @Override
    public void run(String... var1) throws Exception {
        log.info(" CommandLineRunner 项目启动，开始执行...");
    }

}

项目启动测试

2022-08-17 20:41:36.148  INFO 696 --- [  restartedMain] o.s.b.w.embedded.tomcat.TomcatWebServer  : Tomcat started on port(s): 8089 (https) with context path '/gc'
2022-08-17 20:41:36.156  INFO 696 --- [  restartedMain] com.chat.gc.GcChatWebrtcApplication      : Started GcChatWebrtcApplication in 18.13 seconds (JVM running for 22.356)
2022-08-17 20:41:36.159  INFO 696 --- [  restartedMain] com.chat.gc.config.MyCommandLineRunner   :  ApplicationRunner 项目启动，开始执行...
2022-08-17 20:41:36.160  INFO 696 --- [  restartedMain] com.chat.gc.config.MyCommandLineRunner   :  CommandLineRunner 项目启动，开始执行...

补充系统退出/关闭时监听

@Component
public class MyApplicationRunner implements ApplicationRunner, DisposableBean {
    private static Logger log = LoggerFactory.getLogger(MyApplicationRunner.class);

    @Override
    public void run(ApplicationArguments args) throws Exception {
        log.info(" ApplicationRunner 项目启动，开始执行...");
    }

    @Override
    public void destroy() throws Exception {
        log.info(" ApplicationRunner 系统停止运行，开始关闭...");
    }
}

日志：

2023-02-02 15:53:35.457  INFO 304 --- [           main] usi.paofu.PaofuApplication               : Started PaofuApplication in 18.515 seconds (JVM running for 25.814)
2023-02-02 15:53:35.460  INFO 304 --- [           main] usi.paofu.run.MyApplicationRunner        :  ApplicationRunner 项目启动，开始执行...
Disconnected from the target VM, address: '127.0.0.1:50138', transport: 'socket'
2023-02-02 15:54:38.641  INFO 304 --- [extShutdownHook] o.s.s.concurrent.ThreadPoolTaskExecutor  : Shutting down ExecutorService 'applicationTaskExecutor'
2023-02-02 15:54:38.645  INFO 304 --- [extShutdownHook] usi.paofu.run.MyApplicationRunner        :  ApplicationRunner 系统停止运行，开始关闭...
2023-02-02 15:54:38.706  INFO 304 --- [extShutdownHook] com.alibaba.druid.pool.DruidDataSource   : {dataSource-1} closed

参考：https://www.cnblogs.com/cnsyear/p/12732168.html