26-RestHighLevelClient----高亮&分页&排序&指定返回字段

高亮查询和query同时使用时，高亮查询的字段和query字段需要一致。若query查询全部，而高亮查询是查询某一个特定字段，则高亮查询不会生效

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@SpringBootTest
public class RestHighLevelClientOpsTest {
 
    private RestHighLevelClient restHighLevelClient;
 
    @Autowired
    public RestHighLevelClientOpsTest(RestHighLevelClient restHighLevelClient) {
        this.restHighLevelClient = restHighLevelClient;
    }
 
    /**
     * 查询所有 分页查询 form 起始位置  size 每页展示记录的条数
     */
    @Test
    public void testSearch() throws IOException {
        SearchRequest searchRequest = new SearchRequest("products");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        sourceBuilder.query(QueryBuilders.matchAllQuery())
                .from(0)    //起始位置：start=（page-1）*size
                .size(1);   //每页显示条数
 
        searchRequest.source(sourceBuilder);
 
        SearchResponse search = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
 
        System.out.println("总条数：" + search.getHits().getTotalHits().value);
        System.out.println("获取文档最大得分：" + search.getHits().getMaxScore());
 
        SearchHit[] hits = search.getHits().getHits();
        for (SearchHit hit : hits) {
            System.out.println(hit.getSourceAsString());
        }
    }
 
    /**
     * 查询结果默认是按分数排序，我们可以手动指定排序规则
     * 排序：按价格排序
     */
    @Test
    public void testSort() throws IOException {
        SearchRequest searchRequest = new SearchRequest("products");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
        sourceBuilder.query(QueryBuilders.matchAllQuery()).sort("price", SortOrder.ASC);
        searchRequest.source(sourceBuilder);
 
        SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
 
        System.out.println("总条数：" + searchResponse.getHits().getTotalHits().value);
        System.out.println("最大得分：" + searchResponse.getHits().getMaxScore());
 
        SearchHit[] hits = searchResponse.getHits().getHits();
        for (SearchHit hit : hits) {
            System.out.println(hit.getSourceAsString());
        }
    }
 
    /**
     * 指定返回的字段
     */
    @Test
    public void testReturn() throws IOException {
        SearchRequest searchRequest = new SearchRequest("products");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
 
        //之所以设置两个数组，是因为如果我们字段很多的时候，我们业务需求只希望查询/排除很少一部分的字段，则只需要在查询/排除数组里面写那仅有的几个字段即可，省时省力
        sourceBuilder.query(QueryBuilders.matchAllQuery()).fetchSource(new String[]{"title"}, new String[]{});//参数1：包含的字段数组   参数2：排除的字段数组
 
        searchRequest.source(sourceBuilder);
 
        SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
 
        System.out.println("总条数：" + searchResponse.getHits().getTotalHits().value);
        System.out.println("最大得分：" + searchResponse.getHits().getMaxScore());
 
        SearchHit[] hits = searchResponse.getHits().getHits();
        for (SearchHit hit : hits) {
            System.out.println(hit.getSourceAsString());
        }
    }
 
    /**
     * 高亮查询
     */
    @Test
    public void testHighlight() throws IOException {
        SearchRequest searchRequest = new SearchRequest("products");
        SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
 
        //高亮器
        HighlightBuilder highlightBuilder = new HighlightBuilder();
        highlightBuilder.requireFieldMatch(false)//因为高亮查询默认是对查询字段即description就行高亮，可以关闭字段匹配，这样就可以对查询到的多个字段（前提是有关键词并且改字段可以分词）进行高亮显示
                        .field("description")//若有关键字切可以分词，则可以高亮，写*可以匹配所有字段
                        .field("title")//若有关键字切可以分词，则可以高亮，写*可以匹配所有字段
                        .preTags("<span style='color:red;'>")//手动前缀标签
                        .postTags("</span>");
 
        sourceBuilder.query(QueryBuilders.termQuery("description", "好吃")).highlighter(highlightBuilder);///高亮搜索
        searchRequest.source(sourceBuilder);
 
        SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
        SearchHit[] hits = searchResponse.getHits().getHits();
        for (SearchHit hit : hits) {
            //获取高亮字段
            Map<String, HighlightField> highlightFields = hit.getHighlightFields();
 
            //如果高亮字段包含在description中
            if (highlightFields.containsKey("description")){
                System.out.println("description中有这个字段");
                Text[] fragments = highlightFields.get("description").getFragments();
                for (Text fragment : fragments) {
                    System.out.println(fragment);
                }
            }
 
            //如果高亮字段包含在title中
            if (highlightFields.containsKey("title")){
                System.out.println("title中有这个字段");
                Text[] fragments = highlightFields.get("title").getFragments();
                for (Text fragment : fragments) {
                    System.out.println(fragment);
                }
            }
        }
    }
}