第一篇需要實現一個最簡單的需求：某個任務定時執行，多臺機子只讓其中一臺機子執行任務

一、安裝?分布式應用程序協調服務 zookeeper，安裝步驟在鏈接里面

二、在springboot項目中引入?elastic-job 依賴，我這里用的 springboot 2.0.5 版本

整合代碼參考官方的springboot demo

對應的??elastic-job 版本

2.1.5

com.dangdang

elastic-job-lite-core

${elastic-job.version}

com.dangdang

elastic-job-lite-spring

${elastic-job.version}

依賴XML代碼

application.yaml 加入配置

regCenter:

serverList: localhost:2181

namespace: my-project

simpleJob:

cron: 0/15 * * * * ?

shardingTotalCount: 1

shardingItemParameters: 0=a

dataflowJob:

cron: 0/5 * * * * ?

shardingTotalCount: 3

shardingItemParameters: 0=Beijing,1=Shanghai,2=Guangzhou

application.yaml 配置代碼

三、作業代碼(simpleJob類型的任務)，把官方的demo拿到自己的項目中來就行，注意添加一個@Component注解在類上

/** Copyright 1999-2015 dangdang.com.

*

* Licensed under the Apache License, Version 2.0 (the "License");

* you may not use this file except in compliance with the License.

* You may obtain a copy of the License at

*

*http://www.apache.org/licenses/LICENSE-2.0*

* Unless required by applicable law or agreed to in writing, software

* distributed under the License is distributed on an "AS IS" BASIS,

* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

* See the License for the specific language governing permissions and

* limitations under the License.

*

*/

packagecom.dianji.task_server.job.exec;importcom.dangdang.ddframe.job.api.ShardingContext;importcom.dangdang.ddframe.job.api.simple.SimpleJob;importlombok.extern.slf4j.Slf4j;importorg.springframework.beans.factory.annotation.Value;importorg.springframework.stereotype.Component;importjava.text.MessageFormat;importjava.text.SimpleDateFormat;importjava.util.Date;

@Slf4j

@Componentpublic class SpringSimpleJob implementsSimpleJob {

@Value("${flag}")privateString serverFlag;

@Overridepublic void execute(finalShardingContext shardingContext) {int shardingItem =shardingContext.getShardingItem();if (shardingItem == 0) {

log.info("這是來自『{}』的任務，SIMPLE「SpringSimpleJob_execute」", serverFlag + ":" +shardingContext.getShardingParameter());

String logStr= "Item: {0} | Parameter: {1} | : {2} | Time: {3} | Thread: {4} | {5}";

logStr=MessageFormat.format(logStr, shardingContext.getShardingItem(),

shardingContext.getShardingParameter(),new SimpleDateFormat("HH:mm:ss").format(newDate()),

Thread.currentThread().getId(),"SIMPLE「SpringSimpleJob_execute」");

log.info(logStr);

}else if (shardingItem == 1) {

log.info("這是來自『{}』的任務", serverFlag + ":" +shardingContext.getShardingParameter());

}else if (shardingItem == 2) {

log.info("這是來自『{}』的任務", shardingContext.getShardingParameter());

}

}

}

作業任務代碼

四、配置作業(直接將官方的配置代碼拿進自己的項目中)

/** Copyright 1999-2015 dangdang.com.

*

* Licensed under the Apache License, Version 2.0 (the "License");

* you may not use this file except in compliance with the License.

* You may obtain a copy of the License at

*

*http://www.apache.org/licenses/LICENSE-2.0*

* Unless required by applicable law or agreed to in writing, software

* distributed under the License is distributed on an "AS IS" BASIS,

* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

* See the License for the specific language governing permissions and

* limitations under the License.

*

*/

packagecom.dianji.task_server.job.config;importcom.dangdang.ddframe.job.api.simple.SimpleJob;importcom.dangdang.ddframe.job.config.JobCoreConfiguration;importcom.dangdang.ddframe.job.config.simple.SimpleJobConfiguration;importcom.dangdang.ddframe.job.event.JobEventConfiguration;importcom.dangdang.ddframe.job.lite.api.JobScheduler;importcom.dangdang.ddframe.job.lite.config.LiteJobConfiguration;importcom.dangdang.ddframe.job.lite.spring.api.SpringJobScheduler;importcom.dangdang.ddframe.job.reg.zookeeper.ZookeeperRegistryCenter;importcom.dianji.task_server.job.exec.SpringSimpleJob;importorg.springframework.beans.factory.annotation.Value;importorg.springframework.context.annotation.Bean;importorg.springframework.context.annotation.Configuration;importjavax.annotation.Resource;

@Configurationpublic classSimpleJobConfig {

@ResourceprivateZookeeperRegistryCenter regCenter;

@ResourceprivateJobEventConfiguration jobEventConfiguration;

@BeanpublicSimpleJob simpleJob() {return newSpringSimpleJob();

}

@Bean(initMethod= "init")public JobScheduler simpleJobScheduler(final SimpleJob simpleJob, @Value("${simpleJob.cron}") final String cron, @Value("${simpleJob.shardingTotalCount}") final intshardingTotalCount,

@Value("${simpleJob.shardingItemParameters}") finalString shardingItemParameters) {return newSpringJobScheduler(simpleJob, regCenter, getLiteJobConfiguration(simpleJob.getClass(), cron, shardingTotalCount, shardingItemParameters), jobEventConfiguration);

}private LiteJobConfiguration getLiteJobConfiguration(final Class extends SimpleJob> jobClass, final String cron, final int shardingTotalCount, finalString shardingItemParameters) {return LiteJobConfiguration.newBuilder(newSimpleJobConfiguration(JobCoreConfiguration.newBuilder(

jobClass.getName(), cron, shardingTotalCount).shardingItemParameters(shardingItemParameters).build(), jobClass.getCanonicalName())).overwrite(true).build();

}

}

作業配置代碼

五、最簡單的整合步驟就完成了，啟動應用(分別啟動三個進程)，看見任務開始執行了

最簡單的任務需求得到了滿足，定時執行，多臺機子只讓其中一臺機子執行任務

關于分片的數量設置，實際操作了一把

假如：有3個進程實例

并且elastic-job 設置

分片 1 時：3個進程只有1一個進程執行1次任務，共執行1次任務

分片 2 時：3個進程中的2個進程一共執行2次任務，共執行2次任務

分片 3 時：3個進程每個執行1次任務，共執行3次任務

分片 4 時：3個進程同時一共執行4次任務，共執行4次任務

分片 5 時：3個進程同時一共執行5次任務，共執行5次任務

分片為X時，此任務同時在Y臺個進程里面執行X次。

這樣就可以根據不同的使用場景配置不同的分片數量了

總結

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