黑马JavaRestClient查询文档

1、查询

查询的基本步骤是:

1.创建SearchRequest对象

2.准备Request.source()，也就是DSL。

QueryBuilders来构建查询条件

传入Request.source()的 query()方法

3.发送请求，得到结果

4.解析结果(参考JSON结果，从外到内，逐层解析)
java和dsl对应关系 response和dsl查询结果对应关系

java 复制代码

@Test
 void testSearchMatchall() throws IOException {
    SearchRequest request = new SearchRequest("hotel");
     request.source().query(QueryBuilders.matchAllQuery());
    SearchResponse response = client.search(request, RequestOptions.DEFAULT);
    SearchHits hits = response.getHits();
    long value = hits.getTotalHits().value;
    System.out.println(value);
    SearchHit[] hits1 = hits.getHits();
    for (SearchHit hit : hits1) {
        String string = hit.getSourceAsString();
        //反序列化
        HotelDoc hotelDoc = JSON.parseObject(string, HotelDoc.class);
        System.out.println(hotelDoc);
    }
}

bool查询示例：

java 复制代码

@Test
    void testSearchBoolQuery() throws IOException {
        //准备request
        SearchRequest request = new SearchRequest("hotel");
        //准备boolQuery
        BoolQueryBuilder bool = QueryBuilders.boolQuery();
        //准备boolQuery中的条件
        bool.must(QueryBuilders.termQuery("city","杭州"));
        bool.filter(QueryBuilders.rangeQuery("price").lte(250));

        request.source().query(bool);
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        extracted(response);
    }



private static void extracted(SearchResponse response) {
        SearchHits hits = response.getHits();
        long value = hits.getTotalHits().value;
        System.out.println(value);
        SearchHit[] hits1 = hits.getHits();
        for (SearchHit hit : hits1) {
            String string = hit.getSourceAsString();
            //反序列化
            HotelDoc hotelDoc = JSON.parseObject(string, HotelDoc.class);
            System.out.println(hotelDoc);
        }
    }

要构建查询条件，只要记住一个类:QueryBuilders

2、排序和分页

java 复制代码

@Test
    void testSearchSort() throws IOException {
        //准备request
        SearchRequest request = new SearchRequest("hotel");
        //准备query，所有数据
        request.source().query(QueryBuilders.matchAllQuery());
        //设置分页，从0开始，5条数据
        request.source().from(0).size(5);
        //设置排序，升序
        request.source().sort("price", SortOrder.ASC);
        //发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        //解析结果
        extracted(response);
    }

ps：一如dsl语句中一般，query字段和from、size、sort字段平级，因此都是在source()之后设置

3、高亮

java 复制代码

@Test
    void testSearchHightlight() throws IOException {
        //准备request
        SearchRequest request = new SearchRequest("hotel");
        //准备query，所有数据
        request.source().query(QueryBuilders.matchQuery("all","如家"));
        //准备hightlight字段
        request.source().highlighter(new HighlightBuilder().field("name").requireFieldMatch(false));
        //发送请求
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        //解析结果
        highlightextracted(response);
    }



private static void highlightextracted(SearchResponse response) {
        SearchHits hits = response.getHits();
        long value = hits.getTotalHits().value;
        System.out.println(value);
        SearchHit[] hits1 = hits.getHits();
        for (SearchHit hit : hits1) {
            String string = hit.getSourceAsString();
            //反序列化
            HotelDoc hotelDoc = JSON.parseObject(string, 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字段
                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);
        }
    }

所有搜索DSL的构建，记住一个API:

SearchRequest的source()方法。

高亮结果解析是参考JSON结果，逐层解析