Elatic job quick start

See the previous document for the basic environment https://blog.csdn.net/qq_45745830/article/details/121624158?spm=1001.2014.3001.5502https://blog.csdn.net/qq_45745830/article/details/121624158?spm=1001.2014.3001.5502

Introduction to distributed task scheduling

At present, most applications are distributed or micro services, so we need distributed task scheduling. At present, the popular distributed task scheduling mainly include elastic job, XXL job, quartz, etc. Let's make a comparison here:

Static task case

It's easy to use elastic job. Next, let's learn about the use of elastic job. In the case here, we first implement the static task case. The static task case is written in advance, that is, the execution time.

To create a Zookeeper:

docker run -d --name zk \ --net seckill_network --ip 172.36.0.16 \ --restart=always \ -v /etc/localtime:/etc/localtime \ -p 3181:2181 zookeeper:3.4.14

Case realization steps:

1) Introducing dependencies in seckill goods

<!-- ElasticJobAutoConfiguration Auto configuration class function--> <dependency> <groupId>com.github.kuhn-he</groupId> <artifactId>elastic-job-lite-spring-boot-starter</artifactId> <version>2.1.5</version> </dependency>

2) Configure elastic job

Configure elastic job in bootstrap.yml as follows:

server: port: 28889 spring: main: #No error reporting allow-circular-references: true allow-bean-definition-overriding: true application: name: job-springboot datasource: #Connect to database driver-class-name: com.mysql.jdbc.Driver url: jdbc:mysql://localhost:3306/elastic_job_demo?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC username: root password: root zkserver: zk-server:3181 #Dynamic Task Usage zknamespace: zknamesp ​ elaticjob: #Static Task Usage zookeeper: server-lists: zk-server:3181 #zookeeper's address namespace: updatetask #Scheduled task namespace

)Task creation

Create com.seckill.goods.task.statictask.StaticJob with the following code:

@Component @ElasticSimpleJob( cron = "1/5 * * * * ?", //Task execution cycle jobName = "updatetask", //Consistent with scheduled task namespace shardingTotalCount = 1 //Slice ) public class StaticJob implements SimpleJob { ​ /** * Business processing method */ @Override public void execute(ShardingContext shardingContext) { SimpleDateFormat simpleDateFormat = new SimpleDateFormat("HH:mm:ss"); System.out.println("Time:" + simpleDateFormat.format(new Date())); } }

Explanation:

Dynamic task case

1. Registry configuration

bootstrap.yml add configuration

# Dynamic timed task zkserver: zk-server:3181 zknamespace: zknamesp

2. Create task

Create task class: com.seckill.goods.task.dynamic.DynamicJob

public class DynamicJob implements SimpleJob { //Get the classes we need through spring; private FileService fileService= GetSpringBean.get(FileService.class); /** * Implement corresponding tasks */ @Override public void execute(ShardingContext shardingContext) { fileService.all();//Get database System.out.println(); //Get requested parameters String s = HttpUtil.get("https://www.baidu.com/"); System.out.println(s); String id = shardingContext.getJobParameter(); SimpleDateFormat simpleDateFormat = new SimpleDateFormat("HH:mm:ss"); String jobName = shardingContext.getJobName(); System.out.println(jobName + "Time:" + simpleDateFormat.format(new Date()) + ":::" + id); } }

@Component public class GetSpringBean implements ApplicationContextAware { //spring class manager ​ // Declare a static variable to hold the spring container context @Autowired private static ApplicationContext context; ​ @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { this.context = applicationContext; } ​ public static <T> T get(Class<T> clazz) { return context.getBean(clazz); } }

Listener usage

Write listener: com.seckill.goods.task.dynamic.dynamicplistener

public class DynamicListener extends AbstractDistributeOnceElasticJobListener { ​ /** * Constructor */ public DynamicListener(long startedTimeoutMilliseconds, long completedTimeoutMilliseconds) { super(startedTimeoutMilliseconds, completedTimeoutMilliseconds); } ​ /** * Pre execution notice */ @Override public void doBeforeJobExecutedAtLastStarted(ShardingContexts shardingContexts) { System.out.println("=======doBeforeJobExecutedAtLastStarted======="); } ​ /** * Post execution notification */ @Override public void doAfterJobExecutedAtLastCompleted(ShardingContexts shardingContexts) { System.out.println("=======doAfterJobExecutedAtLastCompleted======="); } }

Create configuration class and configure registry information, com.seckill.goods.task.dynamic.ElasticjobDynamicConfig:

@Configuration public class ElasticjobDynamicConfig { ​ @Value("$") private String zkserver; @Value("$") private String zknamespace; ​ @Autowired private ZookeeperRegistryCenter zookeeperRegistryCenter; @Autowired private DynamicListener dynamicListener; ​ /** * 1.Configure initialization data */ @Bean public ZookeeperConfiguration zkConfig() { //1.Zookeeper address //2. Scheduled task namespace return new ZookeeperConfiguration(zkserver, zknamespace); } ​ /** * 2.Register initialization data */ @Bean(initMethod = "init") public ZookeeperRegistryCenter registryCenter(ZookeeperConfiguration zkConfig) { return new ZookeeperRegistryCenter(zkConfig); } /** * monitor */ @Bean public DynamicListener dynamicListener() { return new DynamicListener(10000L, 100000L); } ​ /** * 3.Dynamically add scheduled task cases */ public void addDynamicTask(String jobName, String cron, int shardingTotalCount, SimpleJob instance, String id) { //1. Add the task operator of elastjob Lite LiteJobConfiguration liteJobConfiguration = LiteJobConfiguration.newBuilder( new SimpleJobConfiguration( JobCoreConfiguration.newBuilder(jobName, cron, shardingTotalCount) .jobParameter(id) //Additional parameters .build(), instance.getClass().getName()) ).overwrite(true).build();//overwrite(true) overwrites the original task with the same name ​ //2. Add the task operator of Lite to the task launcher of Spring and initialize it new SpringJobScheduler(instance, zookeeperRegistryCenter, liteJobConfiguration, dynamicListener).init(); } //cron expression format private static final String cron = "ss mm HH dd MM ? yyyy"; ​ /** * Convert time to Cron expression * "1/5 * * * * ?"; */ public static String date2cron(Date date) { SimpleDateFormat simpleDateFormat = new SimpleDateFormat(cron); return simpleDateFormat.format(date); } ​ }

Test class: http://localhost:28889/task?jobName=ytx2&time=5000&id=1 Execute once in five seconds

@RestController @RequestMapping(value = "/task") public class TaskController { ​ @Autowired private ElasticjobDynamicConfig elasticjobDynamicConfig; ​ /** * Dynamic timed task case test */ @GetMapping public String task(String jobName, Long time, String id) { // String cron = "0/" + time + " * * * * ?"; //Delay execution in milliseconds after the current time String cron = ElasticjobDynamicConfig.date2cron(new Date(System.currentTimeMillis() + time)); elasticjobDynamicConfig.addDynamicTask(jobName, cron, 1, new DynamicJob(), id); return "Execution succeeded!"; } }

29 November 2021, 20:27 | Views: 7637