用JAVA写一个定时任务，定时清理es mtime 30天之前的数据 采用 delete_by_query

可以使用 Quartz 定时任务框架来实现，以下是一个简单的示例代码：

首先引入相关依赖：

<dependency>
  <groupId>org.quartz-scheduler</groupId>
  <artifactId>quartz</artifactId>
  <version>2.3.2</version>
</dependency>
<dependency>
  <groupId>org.elasticsearch.client</groupId>
  <artifactId>elasticsearch-rest-high-level-client</artifactId>
  <version>7.0.0</version>
</dependency>

然后定义一个 Job 类来执行清理操作：

import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.deletebyquery.DeleteByQueryRequest;
import org.elasticsearch.action.deletebyquery.DeleteByQueryResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.index.query.QueryBuilders;
import org.quartz.Job;
import org.quartz.JobExecutionContext;
import org.quartz.JobExecutionException;

import java.io.IOException;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.util.Date;

public class EsCleanJob implements Job {
    private RestHighLevelClient esClient;

    public EsCleanJob(RestHighLevelClient esClient) {
        this.esClient = esClient;
    }

    @Override
    public void execute(JobExecutionContext context) throws JobExecutionException {
        System.out.println("开始清理es数据...");
        // 计算30天前的时间戳
        LocalDateTime thirtyDaysAgo = LocalDateTime.now().minusDays(30);
        long timestamp = thirtyDaysAgo.toInstant(ZoneOffset.of("+8")).toEpochMilli();
        // 构建 delete by query 请求
        DeleteByQueryRequest request = new DeleteByQueryRequest("index_name");
        request.setQuery(QueryBuilders.rangeQuery("mtime").lt(timestamp));
        // 执行 delete by query 操作
        try {
            DeleteByQueryResponse response = esClient.deleteByQuery(request, RequestOptions.DEFAULT);
            System.out.println("清理完成，删除 " + response.getDeleted() + " 条数据");
        } catch (IOException e) {
            throw new JobExecutionException("清理es数据失败", e);
        }
    }
}

最后在主函数中启动定时任务：

import org.elasticsearch.client.RestHighLevelClient;
import org.quartz.*;
import org.quartz.impl.StdSchedulerFactory;

public class EsCleanScheduler {
    public static void main(String[] args) throws SchedulerException {
        // 创建 es 客户端
        RestHighLevelClient esClient = new RestHighLevelClient(/* es 配置 */);
        // 创建 JobDetail 实例
        JobDetail jobDetail = JobBuilder.newJob(EsCleanJob.class).withIdentity("esCleanJob").build();
        // 创建 Trigger 实例
        Trigger trigger = TriggerBuilder.newTrigger()
                .withIdentity("esCleanTrigger")
                .withSchedule(SimpleScheduleBuilder.repeatSecondlyForever(86400)) // 每隔一天执行一次
                .build();
        // 创建 Scheduler 实例
        SchedulerFactory schedulerFactory = new StdSchedulerFactory();
        Scheduler scheduler = schedulerFactory.getScheduler();
        scheduler.start();
        scheduler.scheduleJob(jobDetail, trigger);
    }
}

这样就完成了定时清理 es 数据的任务。