分布式搜索引擎ElasticSearch——搜索功能

分布式搜索引擎ElasticSearch——搜索功能

DSL查询文档

DSL查询分类

DSL官方文档

全文检索查询

精确查询

地理查询

复合查询

Function Score Query

function score query

Boolean Query

搜索结果处理

排序

分页

官方文档

高亮

RestClient查询文档

快速入门

public class HotelSearchTest {
    private RestHighLevelClient client;

    @Test
    void testMatchAll() throws IOException {
        // 1. 准备Request
        SearchRequest request = new SearchRequest("hotel");
        // 2. 准备DSL
        request.source().query(QueryBuilders.matchAllQuery());
        // 3. 发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);

        // 4. 解析响应
        SearchHits searchHits = response.getHits();
        // 4.1 获取总条数
        long total = searchHits.getTotalHits().value;
        System.out.println("共搜索到" + total + "条数据");
        // 4.2 文档数组
        SearchHit[] hits = searchHits.getHits();
        // 4.3 遍历
        for (SearchHit hit : hits) {
            // 获取文档source
            String json = hit.getSourceAsString();
            // 反序列化
            HotelDoc hotelDoc = JSON.parseObject(json, HotelDoc.class);
            System.out.println("hotelDoc = " + hotelDoc);
        }
        System.out.println(response);
    }

    @BeforeEach
    void setUp(){
        this.client = new RestHighLevelClient(RestClient.builder(
                HttpHost.create("http://192.168.10.88:9200")
        ));
    }

    @AfterEach
    void tearDown() throws IOException {
        this.client.close();
    }
}

match，term，range，bool查询

  // 全文检索查询
    @Test
    void testMatch() throws IOException {
        // 1. 准备Request
        SearchRequest request = new SearchRequest("hotel");
        // 2. 准备DSL
        request.source().query(QueryBuilders.matchQuery("all","皇冠"));
        // 3. 发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);

        handleResponse(response);
        System.out.println(response);
    }

    // bool查询
    @Test
    void testBool() throws IOException {
        // 1. 准备Request
        SearchRequest request = new SearchRequest("hotel");
        // 2. 准备DSL
        // 2.1 准备BooleanQuery
        BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
        // 2.2 添加term
        boolQuery.must(QueryBuilders.termQuery("city","杭州"));
        // 2.3 添加range
        boolQuery.filter(QueryBuilders.rangeQuery("price").lte(250));

        request.source().query(boolQuery);
        // 3. 发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);

        handleResponse(response);
        System.out.println(response);
    }

    // 抽取解析的代码
    private static void handleResponse(SearchResponse response) {
        // 4. 解析响应
        SearchHits searchHits = response.getHits();
        // 4.1 获取总条数
        long total = searchHits.getTotalHits().value;
        System.out.println("共搜索到" + total + "条数据");
        // 4.2 文档数组
        SearchHit[] hits = searchHits.getHits();
        // 4.3 遍历
        for (SearchHit hit : hits) {
            // 获取文档source
            String json = hit.getSourceAsString();
            // 反序列化
            HotelDoc hotelDoc = JSON.parseObject(json, HotelDoc.class);
            System.out.println("hotelDoc = " + hotelDoc);
        }
    }

排序和分页

// 排序和分页
    @Test
    void testPageAndSort() throws IOException {
        // 页码。每页大小
        int page  = 2, size  = 5;
        // 1. 准备Request
        SearchRequest request = new SearchRequest("hotel");
        // 2. 准备DSL
        // 2.1 query
        request.source().query(QueryBuilders.matchAllQuery());
        // 2.2 配许sort
        request.source().sort("price", SortOrder.ASC);
        // 2.3 分页from， size
        request.source().from((page-1)*size).size(5);
        // 3. 发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 4. 解析响应
        handleResponse(response);
    }

高亮显示

 // 高亮
    @Test
    void testHighlight() throws IOException {
        // 1. 准备Request
        SearchRequest request = new SearchRequest("hotel");
        // 2. 准备DSL
        // 2.1 query
        request.source().query(QueryBuilders.matchQuery("all","如家"));
        // 2.2 高亮
        request.source().highlighter(new HighlightBuilder().field("name").requireFieldMatch(false));
        // 3. 发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        // 4. 解析响应
        handleResponse(response);
    }

就是在前面抽取的解析代码中进一步添加关于高亮的解析部分，因为highlight和source是同级目录的，所以采用的方法类似。

  // 抽取解析的代码
    private static void handleResponse(SearchResponse response) {
        // 4. 解析响应
        SearchHits searchHits = response.getHits();
        // 4.1 获取总条数
        long total = searchHits.getTotalHits().value;
        System.out.println("共搜索到" + total + "条数据");
        // 4.2 文档数组
        SearchHit[] hits = searchHits.getHits();
        // 4.3 遍历
        for (SearchHit hit : hits) {
            // 获取文档source
            String json = hit.getSourceAsString();
            // 反序列化
            HotelDoc hotelDoc = JSON.parseObject(json, HotelDoc.class);
            // 获取高亮结果
            Map<String, HighlightField> highlightFields = hit.getHighlightFields();
            if(!CollectionUtils.isEmpty(highlightFields)){
                // 根据字段名获取高亮结果
                HighlightField highlightField = highlightFields.get("name");
                if(highlightField != null){
                    //  获取高亮值
                    String name = highlightField.getFragments()[0].string();
                    // 覆盖非高亮结果
                    hotelDoc.setName(name);
                }
            }
            System.out.println("hotelDoc = " + hotelDoc);
        }
    }

黑马旅游案例

基本的搜索和分页

@RestController
@RequestMapping("/hotel")
public class HotelController {

    @Autowired
    private IHotelService hotelService;

    @PostMapping("/list")
    public PageResult search(@RequestBody RequestParams params){
        return hotelService.search(params);
    }
}

@Service
public class HotelService extends ServiceImpl<HotelMapper, Hotel> implements IHotelService {

    @Autowired
    private RestHighLevelClient client;

    @Override
    public PageResult search(RequestParams params) {
        try {// 1. 准备Request
            SearchRequest request = new SearchRequest("hotel");
            // 2. 准备DSL
            // 2.1 query
            String key = params.getKey();
            if (key == null || "".equals(key)) {
                request.source().query(QueryBuilders.matchAllQuery());
            } else {
                request.source().query(QueryBuilders.matchQuery("all", key));
            }
            // 2.2 分页
            int page = params.getPage();
            int size = params.getSize();
            request.source().from((page - 1) * size).size(size);
            // 3. 发送请求
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
            // 4. 解析响应
            return handleResponse(response);
        }catch (IOException e){
            throw new RuntimeException(e);
        }
    }


    // 抽取解析的代码
    private PageResult handleResponse(SearchResponse response) {
        // 4. 解析响应
        SearchHits searchHits = response.getHits();
        // 4.1 获取总条数
        long total = searchHits.getTotalHits().value;
        // 4.2 文档数组
        SearchHit[] hits = searchHits.getHits();

        // 4.3 遍历
        List<HotelDoc> hotels = new ArrayList<>();
        for (SearchHit hit : hits) {
            // 获取文档source
            String json = hit.getSourceAsString();
            // 反序列化
            HotelDoc hotelDoc = JSON.parseObject(json, HotelDoc.class);
            hotels.add(hotelDoc);
        }
        // 4.4 封装返回
        return new PageResult(total,hotels);
    }


}

条件过滤

@Override
    public PageResult search(RequestParams params) {
        try {// 1. 准备Request
            SearchRequest request = new SearchRequest("hotel");
            // 2. 准备DSL
            // 2.1 query
            // 构建BooleanQuery

            buildBasicQuery(params, request);

            // 2.2 分页
            int page = params.getPage();
            int size = params.getSize();
            request.source().from((page - 1) * size).size(size);
            // 3. 发送请求
            SearchResponse response = client.search(request, RequestOptions.DEFAULT);
            // 4. 解析响应
            return handleResponse(response);
        }catch (IOException e){
            throw new RuntimeException(e);
        }
    }

    private static void buildBasicQuery(RequestParams params, SearchRequest request) {
        BoolQueryBuilder boolQuery = QueryBuilders.boolQuery();
        // 关键字搜索
        String key = params.getKey();
        if (key == null || "".equals(key)) {
            boolQuery.must(QueryBuilders.matchAllQuery());
        } else {
            boolQuery.must(QueryBuilders.matchQuery("all", key));
        }
        // 条件过滤
        // 城市
        if(params.getCity() !=  null && !"".equals(params.getCity())){
            boolQuery.filter(QueryBuilders.termQuery("city", params.getCity()));
        }
        // 品牌
        if(params.getBrand() !=  null && !"".equals(params.getBrand())){
            boolQuery.filter(QueryBuilders.termQuery("brand", params.getBrand()));
        }
        // 星级
        if(params.getStarName() !=  null && !"".equals(params.getStarName())){
            boolQuery.filter(QueryBuilders.termQuery("starName", params.getStarName()));
        }
        // 价格——范围过滤
        if(params.getMinPrice() != null && params.getMaxPrice() != null){
            boolQuery.filter(QueryBuilders.rangeQuery("price").gte(params.getMinPrice()).lte(params.getMaxPrice()));
        }

        request.source().query(boolQuery);
    }

找周边的酒店

广告置顶

        // 2.  算分控制
        FunctionScoreQueryBuilder functionScoreQuery =
                QueryBuilders.functionScoreQuery(
                        // 原始查询，相关性算分的查询
                        boolQuery,
                        // function score的数组
                        new FunctionScoreQueryBuilder.FilterFunctionBuilder[]{
                                //  其中的一个function score元素
                                new FunctionScoreQueryBuilder.FilterFunctionBuilder(
                                        // 过滤条件
                                        QueryBuilders.termQuery("isAD",true),
                                        // 算分函数
                                        ScoreFunctionBuilders.weightFactorFunction(10)
                                )
                        });