用JAVA写一个定时任务，定时清理es（mtime 修改时间是30天之前）的数据

可以使用Java的ScheduledExecutorService类来实现定时任务，然后使用Java API连接到ES服务器，执行删除操作。

以下是代码示例：

import java.util.Date;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.common.unit.TimeValue;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.sort.SortBuilders;
import org.elasticsearch.search.sort.SortOrder;

public class EsDataCleaner {
  public static void main(String[] args) {
    ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor();
    executor.scheduleAtFixedRate(new EsCleanTask(), 0, 24, TimeUnit.HOURS);
  }

  static class EsCleanTask implements Runnable {
    @Override
    public void run() {
      RestHighLevelClient client = null;

      try {
        // 连接ES服务器
        client = new RestHighLevelClient(RestClient.builder(new HttpHost("localhost", 9200)));

        // 构造搜索请求，查询mtime字段小于30天前的文档
        Date date = new Date(System.currentTimeMillis() - 30 * 24 * 60 * 60 * 1000L);
        SearchRequest searchRequest = new SearchRequest("my_index");
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.query(QueryBuilders.rangeQuery("mtime").lte(date));
        searchSourceBuilder.size(1000);
        searchSourceBuilder.sort(SortBuilders.fieldSort("_doc").order(SortOrder.ASC));
        searchRequest.source(searchSourceBuilder);

        // 执行搜索请求，获取结果
        SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);

        // 遍历结果，逐个删除
        for (SearchHit hit : searchResponse.getHits().getHits()) {
          DeleteRequest deleteRequest = new DeleteRequest("my_index", hit.getId());
          DeleteResponse deleteResponse = client.delete(deleteRequest, RequestOptions.DEFAULT);
          System.out.println("Deleted document " + hit.getId() + ", status: " + deleteResponse.status());
        }
      } catch (Exception e) {
        e.printStackTrace();
      } finally {
        if (client != null) {
          try {
            client.close();
          } catch (Exception e) {
            e.printStackTrace();
          }
        }
      }
    }
  }
}

这里使用了Java API连接到ES服务器，并执行了一次搜索请求，然后遍历搜索结果，逐个删除符合条件的文档。定时任务每24小时运行一次。