spring cloud task Demo搭建

起步：什麼是 spring cloud task

Spring Cloud Task makes it easy to create short lived microservices. We provide capabilities that allow short lived JVM processes to be executed on demand in a production environment.

Spring Cloud Task 是爲了實現短生命週期的、定時執行的、不須要被從新啓動的輕量級應用架構。

建立 Demo

demo 已發佈 https://github.com/Theembers/... 能夠下載參考
1.首先須要建立一個 springBoot 項目

2.除此之外須要加入數據庫依賴,Spring Cloud Task 支持主流數據庫（H二、HSQLDB、MySql、Oracle、Postgres）咱們以mysql爲例

<!--數據庫依賴引入-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
    <version>1.5.7.RELEASE</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

3.引入task依賴

<!--spring cloud task 依賴引入-->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-task-core</artifactId>
    <version>1.0.0.BUILD-SNAPSHOT</version>
</dependency>

4.在application.properties中配置數據庫信息

#DB Configuration:
spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.url = jdbc:mysql://localhost:3306/testdb
spring.datasource.username = root
spring.datasource.password = root

#JPA Configuration:
spring.jpa.database=MySQL
spring.jpa.show-sql=true  
spring.jpa.generate-ddl=true  
spring.jpa.hibernate.ddl-auto=update
#spring.jpa.database-platform=org.hibernate.dialect.MySQL5Dialect
spring.jpa.hibernate.naming_strategy=org.hibernate.cfg.ImprovedNamingStrategy  
#spring.jpa.database=org.hibernate.dialect.MySQL5InnoDBDialect
#spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MYSQL5Dialect

5.編寫你的Application

@SpringBootApplication
@EnableTask
public class SpringCloudTaskApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringCloudTaskApplication.class, args);
    }

    @Bean
    public CommandLineRunner commandLineRunner() {
        return new TestCommandLineRunner();
    }

    public static class TestCommandLineRunner implements CommandLineRunner {
        @Override
        public void run(String... strings) throws Exception {
            System.out.println("this is a Test about spring cloud task.");
            try{
                List<String> list = new ArrayList<>();
                list.get(1);
            }catch (Exception e){
                System.out.println("Error");
                throw e;
            }
        }
    }
}

注意： 以上代碼中經過異常的形式故意經過list.get(1)拋出，便於在數據庫中能夠看到一些數據產生。

6.如今能夠經過運行main方法啓動你的demo，如下是控制檯輸出：

.   ____          _            __ _ _
 /\\ / ___'_ __ _ _(_)_ __  __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
 \\/  ___)| |_)| | | | | || (_| |  ) ) ) )
  '  |____| .__|_| |_|_| |_\__, | / / / /
 =========|_|==============|___/=/_/_/_/
 :: Spring Boot ::        (v1.5.7.RELEASE)

2017-09-25 17:02:43.349  INFO 11592 --- [           main] c.x.s.SpringCloudTaskApplication         : Starting SpringCloudTaskApplication on XinLing with PID 11592 (D:\workspaces\Java\spring-cloud-task\target\classes started by theem in D:\workspaces\Java\spring-cloud-task)
2017-09-25 17:02:43.351  INFO 11592 --- [           main] c.x.s.SpringCloudTaskApplication         : No active profile set, falling back to default profiles: default
2017-09-25 17:02:43.383  INFO 11592 --- [           main] s.c.a.AnnotationConfigApplicationContext : Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@11c20519: startup date [Mon Sep 25 17:02:43 CST 2017]; root of context hierarchy
2017-09-25 17:02:43.938  INFO 11592 --- [           main] j.LocalContainerEntityManagerFactoryBean : Building JPA container EntityManagerFactory for persistence unit 'default'
2017-09-25 17:02:43.947  INFO 11592 --- [           main] o.hibernate.jpa.internal.util.LogHelper  : HHH000204: Processing PersistenceUnitInfo [
    name: default
    ...]
2017-09-25 17:02:43.988  INFO 11592 --- [           main] org.hibernate.Version                    : HHH000412: Hibernate Core {5.0.12.Final}
2017-09-25 17:02:43.989  INFO 11592 --- [           main] org.hibernate.cfg.Environment            : HHH000206: hibernate.properties not found
2017-09-25 17:02:43.989  INFO 11592 --- [           main] org.hibernate.cfg.Environment            : HHH000021: Bytecode provider name : javassist
2017-09-25 17:02:44.016  INFO 11592 --- [           main] o.hibernate.annotations.common.Version   : HCANN000001: Hibernate Commons Annotations {5.0.1.Final}
Mon Sep 25 17:02:44 CST 2017 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Mon Sep 25 17:02:44 CST 2017 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Mon Sep 25 17:02:44 CST 2017 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Mon Sep 25 17:02:44 CST 2017 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Mon Sep 25 17:02:44 CST 2017 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Mon Sep 25 17:02:44 CST 2017 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Mon Sep 25 17:02:44 CST 2017 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Mon Sep 25 17:02:44 CST 2017 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Mon Sep 25 17:02:44 CST 2017 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
Mon Sep 25 17:02:44 CST 2017 WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification.
2017-09-25 17:02:44.307  INFO 11592 --- [           main] org.hibernate.dialect.Dialect            : HHH000400: Using dialect: org.hibernate.dialect.MySQL5Dialect
2017-09-25 17:02:44.406  INFO 11592 --- [           main] org.hibernate.tool.hbm2ddl.SchemaUpdate  : HHH000228: Running hbm2ddl schema update
2017-09-25 17:02:44.422  INFO 11592 --- [           main] j.LocalContainerEntityManagerFactoryBean : Initialized JPA EntityManagerFactory for persistence unit 'default'
2017-09-25 17:02:44.514  INFO 11592 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : Executing SQL script from class path resource [org/springframework/cloud/task/schema-mysql.sql]
2017-09-25 17:02:44.532  INFO 11592 --- [           main] o.s.jdbc.datasource.init.ScriptUtils     : Executed SQL script from class path resource [org/springframework/cloud/task/schema-mysql.sql] in 17 ms.
2017-09-25 17:02:44.636  INFO 11592 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2017-09-25 17:02:44.640  INFO 11592 --- [           main] o.s.c.support.DefaultLifecycleProcessor  : Starting beans in phase 0
this is a Test about spring cloud task.
Error
2017-09-25 17:02:44.675  INFO 11592 --- [           main] utoConfigurationReportLoggingInitializer : 

Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.
2017-09-25 17:02:44.687  INFO 11592 --- [           main] s.c.a.AnnotationConfigApplicationContext : Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@11c20519: startup date [Mon Sep 25 17:02:43 CST 2017]; root of context hierarchy
2017-09-25 17:02:44.688  INFO 11592 --- [           main] o.s.c.support.DefaultLifecycleProcessor  : Stopping beans in phase 0
2017-09-25 17:02:44.689  INFO 11592 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Unregistering JMX-exposed beans on shutdown
2017-09-25 17:02:44.689  INFO 11592 --- [           main] j.LocalContainerEntityManagerFactoryBean : Closing JPA EntityManagerFactory for persistence unit 'default'
2017-09-25 17:02:44.698 ERROR 11592 --- [           main] o.s.boot.SpringApplication               : Application startup failed

java.lang.IllegalStateException: Failed to execute CommandLineRunner
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:735) [spring-boot-1.5.7.RELEASE.jar:1.5.7.RELEASE]
    at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:716) [spring-boot-1.5.7.RELEASE.jar:1.5.7.RELEASE]
    at org.springframework.boot.SpringApplication.afterRefresh(SpringApplication.java:703) [spring-boot-1.5.7.RELEASE.jar:1.5.7.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:304) [spring-boot-1.5.7.RELEASE.jar:1.5.7.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118) [spring-boot-1.5.7.RELEASE.jar:1.5.7.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107) [spring-boot-1.5.7.RELEASE.jar:1.5.7.RELEASE]
    at com.xz.springCoudTask.SpringCloudTaskApplication.main(SpringCloudTaskApplication.java:17) [classes/:na]
Caused by: java.lang.IndexOutOfBoundsException: Index: 1, Size: 0
    at java.util.ArrayList.rangeCheck(ArrayList.java:653) ~[na:1.8.0_91]
    at java.util.ArrayList.get(ArrayList.java:429) ~[na:1.8.0_91]
    at com.xz.springCoudTask.SpringCloudTaskApplication$TestCommandLineRunner.run(SpringCloudTaskApplication.java:31) ~[classes/:na]
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:732) [spring-boot-1.5.7.RELEASE.jar:1.5.7.RELEASE]
    ... 6 common frames omitted


Process finished with exit code 1

7.如下表會在第一次成功執行後建立。

在task_execution中也能夠看到執行記錄，包括錯誤信息

解讀

spring cloud task生命週期

1.在任務開始以前（即在spring初始化以後執行任何CommandLineRunner或ApplicationRunner實現以前）TaskRepository建立一個記錄記錄開始事件的條目，此事件SmartLifecycle#start由Spring Framework觸發，來向系統指出全部bean均可以使用。

The recording of a task will only occur upon the successful bootstrapping of an ApplicationContext. If the context fails to bootstrap at all, the task’s execution will not be recorded.

任務的記錄只有當bean能夠成功加載時纔會被記錄，若是失敗則不會被記錄。

2.在Spring Boot加載完成全部的bean以後，任務執行並更新數據庫中的執行結果和狀態，最後退出。