1.主要依赖

<!-- https://mvnrepository.com/artifact/cn.hutool/hutool-all -->
        <dependency>
            <groupId>cn.hutool</groupId>
            <artifactId>hutool-all</artifactId>
            <version>5.3.10</version>
        </dependency>

        <dependency>
            <groupId>commons-lang</groupId>
            <artifactId>commons-lang</artifactId>
            <version>2.6</version>
        </dependency>

        <!--返回json字符窜的支持  -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.58</version>
        </dependency>
        <!--elasticsearch-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
        </dependency>

简单配置

@Configuration
public class ElasticsearchConfig {

    @Bean
    public RestHighLevelClient restHighLevelClient(){
        RestHighLevelClient client=new RestHighLevelClient(
                RestClient.builder(new HttpHost("127.0.0.1",9200,"http")));
        return client;
    }

}

2.查询条件QueryBuilder的构建方法举例

在使用聚合查询之前我们有必要先来了解下创建查询条件QueryBuilder的几种常用方法

2.1精确查询(必须完全匹配上)

单个匹配termQuery

//不分词查询 参数1: 字段名,参数2:字段查询值,因为不分词,所以汉字只能查询一个字,英语是一个单词.
QueryBuilder queryBuilder=QueryBuilders.termQuery("fieldName", "fieldlValue");
//分词查询,采用默认的分词器
QueryBuilder queryBuilder2 = QueryBuilders.matchQuery("fieldName", "fieldlValue");

多个匹配
//不分词查询,参数1: 字段名,参数2:多个字段查询值,因为不分词,所以汉字只能查询一个字,英语是一个单词.
QueryBuilder queryBuilder=QueryBuilders.termsQuery("fieldName", "fieldlValue1","fieldlValue2...");
//分词查询,采用默认的分词器
QueryBuilder queryBuilder= QueryBuilders.multiMatchQuery("fieldlValue", "fieldName1", "fieldName2", "fieldName3");
//匹配所有文件,相当于就没有设置查询条件
QueryBuilder queryBuilder=QueryBuilders.matchAllQuery();

2.2模糊查询(只要包含即可)

//模糊查询常见的5个方法如下
        //1.常用的字符串查询
        QueryBuilders.queryStringQuery("fieldValue").field("fieldName");//左右模糊
        //2.常用的用于推荐相似内容的查询
        QueryBuilders.moreLikeThisQuery(new String[] {"fieldName"}).addLikeText("pipeidhua");//如果不指定filedName,则默认全部,常用在相似内容的推荐上
        //3.前缀查询  如果字段没分词,就匹配整个字段前缀
        QueryBuilders.prefixQuery("fieldName","fieldValue");
        //4.fuzzy query:分词模糊查询,通过增加fuzziness模糊属性来查询,如能够匹配hotelName为tel前或后加一个字母的文档,fuzziness 的含义是检索的term 前后增加或减少n个单词的匹配查询
        QueryBuilders.fuzzyQuery("hotelName", "tel").fuzziness(Fuzziness.ONE);
        //5.wildcard query:通配符查询,支持* 任意字符串;?任意一个字符
        QueryBuilders.wildcardQuery("fieldName","ctr*");//前面是fieldname,后面是带匹配字符的字符串
        QueryBuilders.wildcardQuery("fieldName","c?r?");

2.3范围查询

//闭区间查询
        QueryBuilder queryBuilder0 = QueryBuilders.rangeQuery("fieldName").from("fieldValue1").to("fieldValue2");
        //开区间查询
        QueryBuilder queryBuilder1 = QueryBuilders.rangeQuery("fieldName").from("fieldValue1").to("fieldValue2").includeUpper(false).includeLower(false);//默认是true,也就是包含
        //大于
        QueryBuilder queryBuilder2 = QueryBuilders.rangeQuery("fieldName").gt("fieldValue");
        //大于等于
        QueryBuilder queryBuilder3 = QueryBuilders.rangeQuery("fieldName").gte("fieldValue");
        //小于
        QueryBuilder queryBuilder4 = QueryBuilders.rangeQuery("fieldName").lt("fieldValue");
        //小于等于
        QueryBuilder queryBuilder5 = QueryBuilders.rangeQuery("fieldName").lte("fieldValue");

2.4组合查询/多条件查询/布尔查询

QueryBuilders.boolQuery()
QueryBuilders.boolQuery().must();//文档必须完全匹配条件,相当于and
QueryBuilders.boolQuery().mustNot();//文档必须不匹配条件,相当于not
QueryBuilders.boolQuery().should();//至少满足一个条件,这个文档就符合should,相当于or

3.工具类

/**
 * @Author: dxf
 * @Description: Elasticsearch工具类
 * @Date: Created in 2020-08-22 17:49
 * @Modified By:
 */
@Component
@Slf4j
public class ElasticsearchUtil {
    //最好不要自定义id 会影响插入速度。

    @Autowired
    @Qualifier("restHighLevelClient")
    private  RestHighLevelClient restHighLevelClient;

    /**
     * 创建索引
     * @param index
     * @return
     */
    public  boolean createIndex(String index) throws IOException {
        if(isIndexExist(index)){
            log.error("Index is  exits!");
            return false;
        }
        //1.创建索引请求
        CreateIndexRequest request = new CreateIndexRequest(index);
        //2.执行客户端请求
        org.elasticsearch.client.indices.CreateIndexResponse response = restHighLevelClient.indices()
                .create(request, RequestOptions.DEFAULT);
        return response.isAcknowledged();
    }

    /**
     * 判断索引是否存在
     * @param index
     * @return
     */
    public  boolean isIndexExist(String index) throws IOException {
        GetIndexRequest request = new GetIndexRequest(index);
        boolean exists = restHighLevelClient.indices().exists(request, RequestOptions.DEFAULT);
        return exists;
    }

    /**
     * 删除索引
     * @param index
     * @return
     */
    public  boolean deleteIndex(String index) throws IOException {
        if(!isIndexExist(index)) {
            log.error("Index is not exits!");
            return false;
        }
        DeleteIndexRequest request = new DeleteIndexRequest(index);
        AcknowledgedResponse delete = restHighLevelClient.indices()
                .delete(request, RequestOptions.DEFAULT);
        return delete.isAcknowledged();
    }

    /**
     * 数据添加,自定义id
     * @param object 要增加的数据
     * @param index      索引,类似数据库
     * @param id         数据ID,为null时es随机生成
     * @return
     */
    public  String addData(Object object, String index, String id) throws IOException {
        //创建请求
        IndexRequest request = new IndexRequest(index);
        //规则 put /test_index/_doc/1
        request.id(id);
        request.timeout(TimeValue.timeValueSeconds(1));
        //将数据放入请求 json
        IndexRequest source = request.source(JSON.toJSONString(object), XContentType.JSON);
        //客户端发送请求
        IndexResponse response = restHighLevelClient.index(request, RequestOptions.DEFAULT);
        return response.getId();
    }

    /**
     * 数据添加 随机id
     * @param object 要增加的数据
     * @param index      索引,类似数据库
     * @return
     */
    public  String addData(Object object, String index) throws IOException {
        return addData(object, index, UUID.randomUUID().toString().replaceAll("-", "").toUpperCase());
    }

    /**
     * 通过ID删除数据
     * @param index 索引,类似数据库
     * @param id    数据ID
     * @return
     */
    public  void deleteDataById(String index,String id) throws IOException {
        DeleteRequest request = new DeleteRequest(index, id);
        restHighLevelClient.delete(request, RequestOptions.DEFAULT);
    }

    /**
     * 通过ID 更新数据
     * @param object     要更新数据
     * @param index      索引,类似数据库
     * @param id         数据ID
     * @return
     */
    public  void updateDataById(Object object, String index, String id) throws IOException {
        UpdateRequest update = new UpdateRequest(index, id);
        update.timeout("1s");
        update.doc(JSON.toJSONString(object), XContentType.JSON);
        restHighLevelClient.update(update, RequestOptions.DEFAULT);
    }

    /**
     * 通过ID获取数据
     * @param index  索引,类似数据库
     * @param id     数据ID
     * @param fields 需要显示的字段,逗号分隔(缺省为全部字段)
     * @return
     */
    public  Map<String,Object> searchDataById(String index, String id, String fields) throws IOException {
        GetRequest request = new GetRequest(index, id);
        if (StringUtils.isNotEmpty(fields)){
            //只查询特定字段。如果需要查询所有字段则不设置该项。
            request.fetchSourceContext(new FetchSourceContext(true,fields.split(","), Strings.EMPTY_ARRAY));
        }
        GetResponse response = restHighLevelClient.get(request, RequestOptions.DEFAULT);
        return response.getSource();
    }

    /**
     * 通过ID判断文档是否存在
     * @param index  索引,类似数据库
     * @param id     数据ID
     * @return
     */
    public  boolean existsById(String index,String id) throws IOException {
        GetRequest request = new GetRequest(index, id);
        //不获取返回的_source的上下文
        request.fetchSourceContext(new FetchSourceContext(false));
        request.storedFields("_none_");
        return restHighLevelClient.exists(request, RequestOptions.DEFAULT);
    }

    /**
     * 批量插入false成功
     * @param index  索引,类似数据库
     * @param objects     数据
     * @return
     */
    public  boolean bulkPost(String index, List<?> objects) {
        BulkRequest bulkRequest = new BulkRequest();
        BulkResponse response=null;
        //最大数量不得超过20万
        for (Object object: objects) {
            IndexRequest request = new IndexRequest(index);
            request.source(JSON.toJSONString(object), XContentType.JSON);
            bulkRequest.add(request);
        }
        try {
            response=restHighLevelClient.bulk(bulkRequest,RequestOptions.DEFAULT);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return response.hasFailures();
    }

    /**
     * 根据经纬度查询范围查找location 经纬度字段,distance 距离中心范围KM,lat  lon 圆心经纬度
     * @param index
     * @param longitude
     * @param latitude
     * @param distance
     * @return
     */
    public  SearchResponse geoDistanceQuery(String index,Float  longitude, Float latitude,String distance) throws IOException {

        if(longitude == null || latitude == null){
            return null;
        }
        //拼接条件
        BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
//        QueryBuilder isdeleteBuilder = QueryBuilders.termQuery("isdelete", false);
        // 以某点为中心,搜索指定范围
        GeoDistanceQueryBuilder distanceQueryBuilder = new GeoDistanceQueryBuilder("location");
        distanceQueryBuilder.point(latitude, longitude);
        //查询单位:km
        distanceQueryBuilder.distance(distance, DistanceUnit.KILOMETERS);
        boolQueryBuilder.filter(distanceQueryBuilder);
//        boolQueryBuilder.must(isdeleteBuilder);

        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        searchSourceBuilder.query(boolQueryBuilder);

        SearchRequest searchRequest = new SearchRequest(index);
        searchRequest.source(searchSourceBuilder);

        SearchResponse searchResponse = restHighLevelClient.search(searchRequest,RequestOptions.DEFAULT);
        return searchResponse;
    }

    /**
     * 获取低水平客户端
     * @return
     */
    public RestClient getLowLevelClient() {
        return restHighLevelClient.getLowLevelClient();
    }

    /**
     * 高亮结果集 特殊处理
     * map转对象 JSONObject.parseObject(JSONObject.toJSONString(map), Content.class)
     * @param searchResponse
     * @param highlightField
     */
    private  List<Map<String, Object>> setSearchResponse(SearchResponse searchResponse, String highlightField) {
        //解析结果
        ArrayList<Map<String,Object>> list = new ArrayList<>();
        for (SearchHit hit : searchResponse.getHits().getHits()) {
            Map<String, HighlightField> high = hit.getHighlightFields();
            HighlightField title = high.get(highlightField);
            Map<String, Object> sourceAsMap = hit.getSourceAsMap();//原来的结果
            //解析高亮字段,将原来的字段换为高亮字段
            if (title!=null){
                Text[] texts = title.fragments();
                String nTitle="";
                for (Text text : texts) {
                    nTitle+=text;
                }
                //替换
                sourceAsMap.put(highlightField,nTitle);
            }
            list.add(sourceAsMap);
        }
        return list;
    }

    /**
     * 查询并分页
     * @param index          索引名称
     * @param query          查询条件
     * @param size           文档大小限制
     * @param fields         需要显示的字段,逗号分隔(缺省为全部字段)
     * @param sortField      排序字段
     * @param highlightField 高亮字段
     * @return
     */
    public  List<Map<String, Object>> searchListData(String index,
                                                     SearchSourceBuilder query,
                                                     Integer size,
                                                     Integer from,
                                                     String fields,
                                                     String sortField,
                                                     String highlightField) throws IOException {
        SearchRequest request = new SearchRequest(index);
        SearchSourceBuilder builder = query;
        if (StringUtils.isNotEmpty(fields)){
            //只查询特定字段。如果需要查询所有字段则不设置该项。
            builder.fetchSource(new FetchSourceContext(true,fields.split(","),Strings.EMPTY_ARRAY));
        }
        from = from <= 0 ? 0 : from*size;
        //设置确定结果要从哪个索引开始搜索的from选项,默认为0
        builder.from(from);
        builder.size(size);
        if (StringUtils.isNotEmpty(sortField)){
            //排序字段,注意如果proposal_no是text类型会默认带有keyword性质,需要拼接.keyword
            builder.sort(sortField+".keyword", SortOrder.ASC);
        }
        //高亮
        HighlightBuilder highlight = new HighlightBuilder();
        highlight.field(highlightField);
        //关闭多个高亮
        highlight.requireFieldMatch(false);
        highlight.preTags("<span style='color:red'>");
        highlight.postTags("</span>");
        builder.highlighter(highlight);
        //不返回源数据。只有条数之类的数据。
//        builder.fetchSource(false);
        request.source(builder);
        SearchResponse response = restHighLevelClient.search(request, RequestOptions.DEFAULT);
        log.error("=="+response.getHits().getTotalHits());
        if (response.status().getStatus() == 200) {
            // 解析对象
            return setSearchResponse(response, highlightField);
        }
        return null;
    }
}