03搜索分页

3.搜索分页

3.1分页分析

页面需要实现分页搜索，所以我们后台每次查询的时候，需要实现分页。用户页面每次会传入当前页和每页查询多少条数据，当然如果不传入每页显示多少条数据，默认查询30条即可。

3.2分页实现

分页使用PageRequest.of( pageNo- 1, pageSize);实现，第1个参数表示第N页，从0开始，第2个参数表示每页显示多少条，实现代码如下：

package com.changgou.search.service.impl;

import com.alibaba.fastjson.JSON;
import com.changgou.search.pojo.SkuInfo;
import com.changgou.search.service.SearchService;
import org.apache.commons.lang.StringUtils;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.Operator;
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.AggregationBuilders;
import org.elasticsearch.search.aggregations.bucket.terms.StringTerms;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightField;
import org.elasticsearch.search.sort.SortBuilders;
import org.elasticsearch.search.sort.SortOrder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.elasticsearch.core.ElasticsearchTemplate;
import org.springframework.data.elasticsearch.core.SearchResultMapper;
import org.springframework.data.elasticsearch.core.aggregation.AggregatedPage;
import org.springframework.data.elasticsearch.core.aggregation.impl.AggregatedPageImpl;
import org.springframework.data.elasticsearch.core.query.NativeSearchQueryBuilder;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

@Service
public class SearchServiceImpl implements SearchService {

    @Autowired
    private ElasticsearchTemplate elasticsearchTemplate;

    @Override
    public Map search(Map<String, String> searchMap) {

        Map<String,Object> resultMap = new HashMap<>();

        //构建查询
        if (searchMap != null){
            //构建查询条件封装对象
            NativeSearchQueryBuilder nativeSearchQueryBuilder = new NativeSearchQueryBuilder();
            BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();

            //按照关键字查询
            if (StringUtils.isNotEmpty(searchMap.get("keywords"))){
                boolQuery.must(QueryBuilders.matchQuery("name",searchMap.get("keywords")).operator(Operator.AND));
            }

            //按照品牌进行过滤查询
            if (StringUtils.isNotEmpty(searchMap.get("brand"))){
                boolQuery.filter(QueryBuilders.termQuery("brandName",searchMap.get("brand")));
            }

            //按照规格进行过滤查询
            for (String key : searchMap.keySet()) {
                if (key.startsWith("spec_")){
                    String value = searchMap.get(key).replace("%2B","+");
                    //spec_网络制式
                    boolQuery.filter(QueryBuilders.termQuery(("specMap."+key.substring(5)+".keyword"),value));
                }
            }

            //按照价格进行区间过滤查询
            if (StringUtils.isNotEmpty(searchMap.get("price"))){
                String[] prices = searchMap.get("price").split("-");
                // 0-500 500-1000
                if (prices.length == 2){
                    boolQuery.filter(QueryBuilders.rangeQuery("price").lte(prices[1]));
                }
                boolQuery.filter(QueryBuilders.rangeQuery("price").gte(prices[0]));
            }
            nativeSearchQueryBuilder.withQuery(boolQuery);

            //按照品牌进行分组(聚合)查询
            String skuBrand="skuBrand";
            nativeSearchQueryBuilder.addAggregation(AggregationBuilders.terms(skuBrand).field("brandName"));

            //按照规格进行聚合查询
            String skuSpec="skuSpec";
            nativeSearchQueryBuilder.addAggregation(AggregationBuilders.terms(skuSpec).field("spec.keyword"));

            //开启分页查询
            String pageNum = searchMap.get("pageNum"); //当前页
            String pageSize = searchMap.get("pageSize"); //每页显示多少条
            if (StringUtils.isEmpty(pageNum)){
                pageNum ="1";
            }
            if (StringUtils.isEmpty(pageSize)){
                pageSize="30";
            }
            //设置分页
            //第一个参数:当前页 是从0开始
            //第二个参数:每页显示多少条
            nativeSearchQueryBuilder.withPageable(PageRequest.of(Integer.parseInt(pageNum)-1,Integer.parseInt(pageSize)));

              
            //开启查询
            /**
             * 第一个参数: 条件构建对象
             * 第二个参数: 查询操作实体类
             * 第三个参数: 查询结果操作对象
             */
            //封装查询结果
            AggregatedPage<SkuInfo> resultInfo = elasticsearchTemplate.queryForPage(nativeSearchQueryBuilder.build(), SkuInfo.class, new SearchResultMapper() {
                @Override
                public <T> AggregatedPage<T> mapResults(SearchResponse searchResponse, Class<T> aClass, Pageable pageable) {
                    //查询结果操作
                    List<T> list = new ArrayList<>();

                    //获取查询命中结果数据
                    SearchHits hits = searchResponse.getHits();
                    if (hits != null){
                        //有查询结果
                        for (SearchHit hit : hits) {
                            //SearchHit转换为skuinfo
                            SkuInfo skuInfo = JSON.parseObject(hit.getSourceAsString(), SkuInfo.class);
                        
                            list.add((T) skuInfo);
                        }
                    }
                    return new AggregatedPageImpl<T>(list,pageable,hits.getTotalHits(),searchResponse.getAggregations());
                }
            });

            //封装最终的返回结果
            //总记录数
            resultMap.put("total",resultInfo.getTotalElements());
            //总页数
            resultMap.put("totalPages",resultInfo.getTotalPages());
            //数据集合
            resultMap.put("rows",resultInfo.getContent());

            //封装品牌的分组结果
           StringTerms brandTerms = (StringTerms) resultInfo.getAggregation(skuBrand);
           List<String> brandList = brandTerms.getBuckets().stream().map(bucket -> bucket.getKeyAsString()).collect(Collectors.toList());
            resultMap.put("brandList",brandList);

            //封装规格分组结果
            StringTerms specTerms= (StringTerms) resultInfo.getAggregation(skuSpec);
            List<String> specList = specTerms.getBuckets().stream().map(bucket -> bucket.getKeyAsString()).collect(Collectors.toList());
            resultMap.put("specList",specList);

            //当前页
            resultMap.put("pageNum",pageNum);
            return resultMap;
        }
        return null;
    }
}

测试如下：