ElasticSearch如何实现查询所有数据

这篇文章主要介绍"ElasticSearch如何实现查询所有数据"，在日常操作中，相信很多人在ElasticSearch如何实现查询所有数据问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答"ElasticSearch如何实现查询所有数据"的疑惑有所帮助！接下来，请跟着小编一起来学习吧！

1，分页查询所有，但最多能查10000 条记录，超过就会报错

 public List getAll(String index, String type, QueryBuilder queryBuilder, Class tClass)  {        SearchResponse searchResponse = buildRequest(index, type, queryBuilder, 0).get();        SearchHits hits = searchResponse.getHits();        int total = (int) hits.totalHits;        List result = new ArrayList<>(total);        addToResult(hits,result,tClass);        int pagesize = 1000;        int page = total / pagesize;        if(total % pagesize != 0){            page++;        }        for (int i = 2; i <= page; i++) {            int from = (i - 1) * pagesize;            searchResponse = buildRequest(index, type, queryBuilder, from).get();            hits = searchResponse.getHits();            addToResult(hits,result,tClass);        }        return result;    }    private SearchRequestBuilder buildRequest(String index,String type,QueryBuilder queryBuilder,int from) {        TransportClient client = elasticSearchManager.getClient("ad");        int pagesize = 1000;        SearchRequestBuilder builder = client                .prepareSearch(index)                .setTypes(type)                .setFrom(from)                .setSize(pagesize)                .setQuery(queryBuilder);        log.info("ElasticsearchDAO query string：\nGET {}/{}/_search\n{} ", index, type, builder.toString());        return builder;    }

2,利用scroll，这是官方推荐的方式

import lombok.extern.slf4j.Slf4j;import org.elasticsearch.action.search.SearchRequestBuilder;import org.elasticsearch.action.search.SearchResponse;import org.elasticsearch.client.transport.TransportClient;import org.elasticsearch.common.unit.TimeValue;import org.elasticsearch.index.query.BoolQueryBuilder;import org.elasticsearch.index.query.QueryBuilder;import org.elasticsearch.index.query.QueryBuilders;import org.elasticsearch.search.SearchHit;import org.elasticsearch.search.SearchHits;import org.elasticsearch.search.aggregations.Aggregation;import org.elasticsearch.search.aggregations.AggregationBuilder;import org.elasticsearch.search.aggregations.Aggregations;import org.elasticsearch.search.aggregations.bucket.MultiBucketsAggregation;import org.elasticsearch.search.aggregations.bucket.terms.Terms;import org.elasticsearch.search.aggregations.metrics.NumericMetricsAggregation;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Component;import org.springframework.util.CollectionUtils;import java.io.IOException;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import java.util.concurrent.ExecutionException;@Slf4j@Componentpublic class ElasticsearchDAO {    @Autowired    private ElasticSearchManager elasticSearchManager;    private int pagesize = 10000;    /**     * es 游标有效期     */    private final int ES_SCROLL_TIME = 10;    public List search(SearchRequest req) throws ExecutionException, InterruptedException {        BoolQueryBuilder boolQuery = req.getQueryBuilder();        List result = getAll(Config.ES_REPORT_INDEX, Config.ES_REPORT_TYPE, boolQuery,ReportDO.class);        return result;    }    /**     * 查询所有     */    private List getAll(String index, String type, QueryBuilder queryBuilder, Class tClass) throws ExecutionException, InterruptedException {        SearchResponse searchResponse = buildRequest(index, type, queryBuilder).get();        String scrollId = searchResponse.getScrollId();        SearchHits hits = searchResponse.getHits();        List result = new ArrayList<>();        addToResult(hits,result,tClass);        while (true){            List list = getScrollResult(scrollId, tClass, result);            if(list == null){                break;            }        }        return result;    }    private  List  getScrollResult(String scrollId,Class tClass, List result) throws ExecutionException, InterruptedException {        TransportClient client = elasticSearchManager.getClient("ad");        SearchResponse searchResponse = client.prepareSearchScroll(scrollId)  //设置游标                .setScroll(TimeValue.timeValueSeconds(ES_SCROLL_TIME))  //设置游标有效期                .execute()                .get();        SearchHits hits = searchResponse.getHits();        SearchHit[] searchHits = hits.getHits();        if(searchHits == null || searchHits.length == 0){            return null;        }        addToResult(hits,result,tClass);        return result;    }    private SearchRequestBuilder buildRequest(String index,String type,QueryBuilder queryBuilder) {        TransportClient client = elasticSearchManager.getClient("ad");        SearchRequestBuilder builder = client                .prepareSearch(index)                .setTypes(type)                .setScroll(TimeValue.timeValueSeconds(ES_SCROLL_TIME))  //设置游标有效期                .setSize(pagesize)                .setQuery(queryBuilder);        log.info("ElasticsearchDAO query string：\nGET {}/{}/_search\n{} ", index, type, builder.toString());        return builder;    }    private void addToResult(SearchHits hits,List result,Class tClass){        for (SearchHit hit : hits) {            String sourceAsString = hit.getSourceAsString();            Object object = JsonUtil.parseObject(sourceAsString, tClass);            result.add(object);        }    }}

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