Spring Cloud Task 的生命周期

àì夳堔傛蜴生んèń 2023-02-28 01:22 35阅读 0赞

### 文章目录 ###

*   *  Spring Cloud Task 的生命周期
     *   *  TaskExecutionListener
         *  注解的方式
     *  参考
     *  源代码

## Spring Cloud Task 的生命周期 ##

> 生命周期是一个任务task实例运行的全过程，也是一个被配置为task的Spring Boot应用被执行的过程(通过添加`@EnableTask`注解配置)

### TaskExecutionListener ###

`TaskExecutionListener`允许我们为任务生命周期中发生的特定事件注册侦听器。创建一个实现`TaskExecutionListener`接口的类。实现TaskExecutionListener接口的类会收到以下事件的通知

*  onTaskStartup: 在将TaskExecution存储到TaskRepository之前。
 *  onTaskEnd: 在更新TaskExecution到TaskRepository并标记task的最终状态之前。
 *  onTaskFailed: 在task抛出未处理异常时调用onTaskEnd方法之前。

下面我们通过代码来看看这个Spring Cloud Task 的生命周期：

package com.example;
    
    import org.springframework.boot.CommandLineRunner;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.task.configuration.EnableTask;
    import org.springframework.cloud.task.listener.TaskExecutionListener;
    import org.springframework.cloud.task.repository.TaskExecution;
    import org.springframework.context.annotation.Bean;
    
    @SpringBootApplication
    @EnableTask
    public class LifecycleApplication { 
    
    
        @Bean
        public CommandLineRunner commandLineRunner() { 
            return new MyCommonLineRunner();
        }
    
        @Bean
        public MyTaskExecutionListener taskExecutionListener() { 
            return new MyTaskExecutionListener();
        }
    
    
        public static class MyTaskExecutionListener implements TaskExecutionListener { 
    
            @Override
            public void onTaskStartup(TaskExecution taskExecution) { 
                System.out.println("task start.." + taskExecution.toString());
            }
    
            @Override
            public void onTaskEnd(TaskExecution taskExecution) { 
                System.out.println("task end.." + taskExecution.toString());
            }
    
            @Override
            public void onTaskFailed(TaskExecution taskExecution, Throwable throwable) { 
                System.out.println("task fail.." + taskExecution.toString());
            }
        }
    
    
        public static class MyCommonLineRunner implements CommandLineRunner { 
            @Override
            public void run(String... args) throws Exception { 
                System.out.println("Hello, World");
            }
        }
    
        public static void main(String[] args) { 
            SpringApplication.run(LifecycleApplication.class, args);
        }
    }

然后我们来看看运行的结果：

从运行的输出结果我们可以看出，`onTaskStartup`方法是在`SimpleTaskRepository#createTaskExecution`方法执行之后执行的。`onTaskEnd`方法是在`SimpleTaskRepository#completeTaskExecution`方法执行之前执行的，在`CommandLineRunner#run`方法执行之后之前的。

接下来我们来看看`onTaskFailed`是什么时候执行的，我们来改造一下我们的代码：

package com.example;
    
    import org.springframework.boot.CommandLineRunner;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.task.configuration.EnableTask;
    import org.springframework.cloud.task.listener.TaskExecutionListener;
    import org.springframework.cloud.task.repository.TaskExecution;
    import org.springframework.context.annotation.Bean;
    
    @SpringBootApplication
    @EnableTask
    public class LifecycleApplication { 
    
    
        @Bean
        public CommandLineRunner commandLineRunner() { 
            return new MyCommonLineRunner();
        }
    
        @Bean
        public MyTaskExecutionListener taskExecutionListener() { 
            return new MyTaskExecutionListener();
        }
    
    
        public static class MyTaskExecutionListener implements TaskExecutionListener { 
    
            @Override
            public void onTaskStartup(TaskExecution taskExecution) { 
                System.out.println("task start.." + taskExecution.toString());
            }
    
            @Override
            public void onTaskEnd(TaskExecution taskExecution) { 
                System.out.println("task end.." + taskExecution.toString());
            }
    
            @Override
            public void onTaskFailed(TaskExecution taskExecution, Throwable throwable) { 
                System.out.println("task fail.." + taskExecution.toString());
            }
        }
    
    
        public static class MyCommonLineRunner implements CommandLineRunner { 
            @Override
            public void run(String... args) throws Exception { 
                System.out.println("Hello, World");
                int i = 1 / 0;
            }
        }
    
        public static void main(String[] args) { 
            SpringApplication.run(LifecycleApplication.class, args);
        }
    }

然后我们来看看执行的结果：

.   ____          _            __ _ _
     /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
     \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
      ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v2.4.0-SNAPSHOT) 2020-07-18 19:46:07.832 INFO 11108 --- [ main] com.example.LifecycleApplication : Starting LifecycleApplication using Java 1.8.0_92 on C with PID 11108 (C:\Users\c\Desktop\spring-cloud-task-demo\target\classes started by c in C:\Users\c\Desktop\spring-cloud-task-demo) 2020-07-18 19:46:07.836 INFO 11108 --- [ main] com.example.LifecycleApplication : No active profile set, falling back to default profiles: default 2020-07-18 19:46:08.579 DEBUG 11108 --- [ main] o.s.c.t.c.SimpleTaskAutoConfiguration : Using org.springframework.cloud.task.configuration.DefaultTaskConfigurer TaskConfigurer 2020-07-18 19:46:08.579 DEBUG 11108 --- [ main] o.s.c.t.c.DefaultTaskConfigurer : No DataSource was found, using ResourcelessTransactionManager 2020-07-18 19:46:08.856 DEBUG 11108 --- [ main] o.s.c.t.r.support.SimpleTaskRepository : Creating: TaskExecution{executionId=0, parentExecutionId=null, exitCode=null, taskName='HelloWorld', startTime=Sat Jul 18 19:46:08 GMT+08:00 2020, endTime=null, exitMessage='null', externalExecutionId='null', errorMessage='null', arguments=[]} task start..TaskExecution{executionId=0, parentExecutionId=null, exitCode=null, taskName='HelloWorld', startTime=Sat Jul 18 19:46:08 GMT+08:00 2020, endTime=null, exitMessage='null', externalExecutionId='null', errorMessage='null', arguments=[]} 2020-07-18 19:46:08.884 INFO 11108 --- [ main] com.example.LifecycleApplication : Started LifecycleApplication in 1.508 seconds (JVM running for 3.896) Hello, World task fail..TaskExecution{executionId=0, parentExecutionId=null, exitCode=1, taskName='HelloWorld', startTime=Sat Jul 18 19:46:08 GMT+08:00 2020, endTime=Sat Jul 18 19:46:08 GMT+08:00 2020, exitMessage='null', externalExecutionId='null', errorMessage='java.lang.IllegalStateException: Failed to execute CommandLineRunner
    	at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:788)
    	at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:769)
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:330)
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1244)
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1233)
    	at com.example.LifecycleApplication.main(LifecycleApplication.java:55)
    Caused by: java.lang.ArithmeticException: / by zero
    	at com.example.LifecycleApplication$MyCommonLineRunner.run(LifecycleApplication.java:50)
    	at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:785)
    	... 5 more
    ', arguments=[]} task end..TaskExecution{executionId=0, parentExecutionId=null, exitCode=1, taskName='HelloWorld', startTime=Sat Jul 18 19:46:08 GMT+08:00 2020, endTime=Sat Jul 18 19:46:08 GMT+08:00 2020, exitMessage='null', externalExecutionId='null', errorMessage='java.lang.IllegalStateException: Failed to execute CommandLineRunner
    	at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:788)
    	at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:769)
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:330)
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1244)
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1233)
    	at com.example.LifecycleApplication.main(LifecycleApplication.java:55)
    Caused by: java.lang.ArithmeticException: / by zero
    	at com.example.LifecycleApplication$MyCommonLineRunner.run(LifecycleApplication.java:50)
    	at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:785)
    	... 5 more
    ', arguments=[]} 2020-07-18 19:46:08.894 DEBUG 11108 --- [ main] o.s.c.t.r.support.SimpleTaskRepository : Updating: TaskExecution with executionId=0 with the following {exitCode=1, endTime=Sat Jul 18 19:46:08 GMT+08:00 2020, exitMessage='null', errorMessage='java.lang.IllegalStateException: Failed to execute CommandLineRunner
    	at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:788)
    	at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:769)
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:330)
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1244)
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1233)
    	at com.example.LifecycleApplication.main(LifecycleApplication.java:55)
    Caused by: java.lang.ArithmeticException: / by zero
    	at com.example.LifecycleApplication$MyCommonLineRunner.run(LifecycleApplication.java:50)
    	at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:785)
    	... 5 more
    '} 2020-07-18 19:46:08.895 INFO 11108 --- [ main] ConditionEvaluationReportLoggingListener : Error starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
    2020-07-18 19:46:08.910 ERROR 11108 --- [           main] o.s.boot.SpringApplication               : Application run failed
    
    java.lang.IllegalStateException: Failed to execute CommandLineRunner
    	at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:788) [spring-boot-2.4.0-20200717.195013-207.jar:2.4.0-SNAPSHOT]
    	at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:769) [spring-boot-2.4.0-20200717.195013-207.jar:2.4.0-SNAPSHOT]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:330) [spring-boot-2.4.0-20200717.195013-207.jar:2.4.0-SNAPSHOT]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1244) [spring-boot-2.4.0-20200717.195013-207.jar:2.4.0-SNAPSHOT]
    	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1233) [spring-boot-2.4.0-20200717.195013-207.jar:2.4.0-SNAPSHOT]
    	at com.example.LifecycleApplication.main(LifecycleApplication.java:55) [classes/:na]
    Caused by: java.lang.ArithmeticException: / by zero
    	at com.example.LifecycleApplication$MyCommonLineRunner.run(LifecycleApplication.java:50) ~[classes/:na]
    	at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:785) [spring-boot-2.4.0-20200717.195013-207.jar:2.4.0-SNAPSHOT]
    	... 5 common frames omitted
    
    
    Process finished with exit code 1

当`CommandLineRunner#run`方法抛出未捕获的异常时候，onTaskFailed会被执行，之后还会执行`onTaskEnd`方法，输出了如下内容：

task end..TaskExecution{executionId=0, parentExecutionId=null, exitCode=1, taskName='HelloWorld', startTime=Sat Jul 18 19:46:08 GMT+08:00 2020, endTime=Sat Jul 18 19:46:08 GMT+08:00 2020, exitMessage='null', externalExecutionId='null', errorMessage='java.lang.IllegalStateException: Failed to execute CommandLineRunner

可以看到当有异常抛出的时候，exitCode的值为1，而且errorMessage也有内容显示。

### 注解的方式 ###

我们还可以通过注解的方式去达到上面的目的，去完成我们对生命周期的监听，可以用下面三个注解：

*  @BeforeTask
 *  @AfterTask
 *  @FailedTask

package com.example;
    
    import org.springframework.boot.CommandLineRunner;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.task.configuration.EnableTask;
    import org.springframework.cloud.task.listener.annotation.AfterTask;
    import org.springframework.cloud.task.listener.annotation.BeforeTask;
    import org.springframework.cloud.task.listener.annotation.FailedTask;
    import org.springframework.cloud.task.repository.TaskExecution;
    import org.springframework.context.annotation.Bean;
    
    @SpringBootApplication
    @EnableTask
    public class LifecycleApplication { 
    
    
        @Bean
        public CommandLineRunner commandLineRunner() { 
            return new MyCommonLineRunner();
        }
    
        @BeforeTask
        public void beforeTask(TaskExecution taskExecution){ 
            System.out.println("task start.." + taskExecution.toString());
        }
    
    
        @AfterTask
        public void afterTask(TaskExecution taskExecution){ 
            System.out.println("task end.." + taskExecution.toString());
        }
    
    
        @FailedTask
        public void failedTask(TaskExecution taskExecution){ 
            System.out.println("task fail.." + taskExecution.toString());
        }
    
        public static class MyCommonLineRunner implements CommandLineRunner { 
            @Override
            public void run(String... args) throws Exception { 
                System.out.println("Hello, World");
            }
        }
    
        public static void main(String[] args) { 
            SpringApplication.run(LifecycleApplication.class, args);
        }
    }

然后我们来看看输出的结果：

## 参考 ##

[\[Spring Cloud Task\]2 生命周期特性与任务仓库数据结构][Spring Cloud Task_2]

[Spring Cloud Task 官方文档][Spring Cloud Task]

## 源代码 ##

[https://gitee.com/cckevincyh/Spring-Cloud-Task/tree/lifecycle][https_gitee.com_cckevincyh_Spring-Cloud-Task_tree_lifecycle]

[Spring Cloud Task_2]: https://www.jianshu.com/p/06c5f18cf01d
[Spring Cloud Task]: https://docs.spring.io/spring-cloud-task/docs/current/reference/#getting-started
[https_gitee.com_cckevincyh_Spring-Cloud-Task_tree_lifecycle]: https://gitee.com/cckevincyh/Spring-Cloud-Task/tree/lifecycle