elastic-job的原理简介和使用

<!-- 引入elastic-job-lite核心模块 -->
<dependency>
    <groupId>com.dangdang</groupId>
    <artifactId>elastic-job-lite-core</artifactId>
    <version>2.0.5</version>
</dependency>
<!-- 使用springframework自定义命名空间时引入 -->
<dependency>
    <groupId>com.dangdang</groupId>
    <artifactId>elastic-job-lite-spring</artifactId>
    <version>2.0.5</version>
</dependency>

package com.fanfan.sample001;
 
import com.dangdang.ddframe.job.api.ShardingContext;
import com.dangdang.ddframe.job.api.simple.SimpleJob;
 
import java.util.Date;
 
/**
 * Created by fanfan on 2016/12/20.
 */
public class MySimpleJob implements SimpleJob {
    @Override
    public void execute(ShardingContext shardingContext) {
        System.out.println(String.format("------Thread ID: %s, 任务总片数: %s, 当前分片项: %s",
                Thread.currentThread().getId(), shardingContext.getShardingTotalCount(), shardingContext.getShardingItem()));
        /**
         * 实际开发中，有了任务总片数和当前分片项，就可以对任务进行分片执行了
         * 比如 SELECT * FROM user WHERE status = 0 AND MOD(id, shardingTotalCount) = shardingItem
         */
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:reg="http://www.dangdang.com/schema/ddframe/reg"
       xmlns:job="http://www.dangdang.com/schema/ddframe/job"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
                        http://www.springframework.org/schema/beans/spring-beans.xsd
                        http://www.dangdang.com/schema/ddframe/reg
                        http://www.dangdang.com/schema/ddframe/reg/reg.xsd
                        http://www.dangdang.com/schema/ddframe/job
                        http://www.dangdang.com/schema/ddframe/job/job.xsd">
    <!--配置作业注册中心 -->
    <reg:zookeeper id="regCenter" server-lists="192.168.241.1:2181" namespace="dd-job"
                   base-sleep-time-milliseconds="1000" max-sleep-time-milliseconds="3000" max-retries="3" />
 
    <!-- 配置作业-->
    <job:simple id="mySimpleJob" class="com.fanfan.sample001.MySimpleJob" registry-center-ref="regCenter"
                sharding-total-count="2" cron="0/2 * * * * ?" overwrite="true" />
 
</beans>

package com.fanfan.sample001;
 
import com.dangdang.ddframe.job.api.ShardingContext;
import com.dangdang.ddframe.job.api.dataflow.DataflowJob;
 
import java.util.ArrayList;
import java.util.List;
 
/**
 * Created by fanfan on 2016/12/23.
 */
public class MyDataFlowJob implements DataflowJob<User> {
 
    /*
        status
        0：待处理
        1：已处理
     */
 
    @Override
    public List<User> fetchData(ShardingContext shardingContext) {
        List<User> users = null;
        /**
         * users = SELECT * FROM user WHERE status = 0 AND MOD(id, shardingTotalCount) = shardingItem Limit 0, 30
         */
        return users;
    }
 
    @Override
    public void processData(ShardingContext shardingContext, List<User> data) {
        for (User user: data) {
            System.out.println(String.format("用户 %s 开始计息", user.getUserId()));
            user.setStatus(1);
            /**
             * update user
             */
        }
    }
}

<job:dataflow id="myDataFlowJob" class="com.fanfan.sample001.MyDataFlowJob" registry-center-ref="regCenter"
              sharding-total-count="2" cron="0 0 02 * * ?" streaming-process="true" overwrite="true" />