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！
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public <T>List<T> getAll(String index, String type, QueryBuilder queryBuilder, Class<T> tClass) {
SearchResponse searchResponse = buildRequest(index, type, queryBuilder, 0).get();
SearchHits hits = searchResponse.getHits();
int total = (int) hits.totalHits;
List<T> 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;
}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
@Component
public 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<ReportDO> search(SearchRequest req) throws ExecutionException, InterruptedException {
BoolQueryBuilder boolQuery = req.getQueryBuilder();
List<ReportDO> result = getAll(Config.ES_REPORT_INDEX, Config.ES_REPORT_TYPE, boolQuery,ReportDO.class);
return result;
}
/**
* 查询所有
*/
private <T>List<T> getAll(String index, String type, QueryBuilder queryBuilder, Class<T> tClass) throws ExecutionException, InterruptedException {
SearchResponse searchResponse = buildRequest(index, type, queryBuilder).get();
String scrollId = searchResponse.getScrollId();
SearchHits hits = searchResponse.getHits();
List<T> result = new ArrayList<>();
addToResult(hits,result,tClass);
while (true){
List<T> list = getScrollResult(scrollId, tClass, result);
if(list == null){
break;
}
}
return result;
}
private <T>List<T> getScrollResult(String scrollId,Class<T> tClass, List<T> 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);
}
}
}到此，关于“ElasticSearch如何实现查询所有数据”的学习就结束了，希望能够解决大家的疑惑。理论与实践的搭配能更好的帮助大家学习，快去试试吧！若想继续学习更多相关知识，请继续关注亿速云网站，小编会继续努力为大家带来更多实用的文章！
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原文链接：https://my.oschina.net/u/3574106/blog/4554451
