標簽：ElasticSearch8.Kibana8；

一、簡介

Elasticsearch是一個分布式、RESTful風格的搜索和數據分析引擎，適用于各種數據類型，數字、文本、地理位置、結構化數據、非結構化數據；

在實際的工作中，歷經過Elasticsearch從6.0到7.0的版本升級，而這次SpringBoot3和ES8.0的集成，雖然腳本的語法變化很小，但是Java客戶端的API語法變化很大；

二、環境搭建

1、下載安裝包

需要注意的是，這些安裝包的版本要選擇對應的，不然容易出問題；

軟件包：elasticsearch-8.8.2-darwin-x86_64.tar.gz
分詞器工具：elasticsearch-analysis-ik-8.8.2.zip
可視化工具：kibana-8.8.2-darwin-x86_64.tar.gz

2、服務啟動

不論是ES還是Kibana，在首次啟動后，會初始化很多配置文件，可以根據自己的需要做相關的配置調整，比如常見的端口調整，資源占用，安全校驗等；

1、啟動ES
elasticsearch-8.8.2/bin/elasticsearch本地訪問：localhost:92002、啟動Kibana
kibana-8.8.2/bin/kibana本地訪問：http://localhost:5601# 3、查看安裝的插件
http://localhost:9200/_cat/plugins  ->  analysis-ik 8.8.2

三、工程搭建

1、工程結構

2、依賴管理

在starter-elasticsearch組件中，實際上依賴的是elasticsearch-java組件的8.7.1版本；

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-elasticsearch</artifactId><version>${spring-boot.version}</version>
</dependency>

3、配置文件

在上面環境搭建的過程中，已經禁用了用戶和密碼的登錄驗證，配置ES服務地址即可；

spring:# ElasticSearch配置elasticsearch:uris: localhost:9200

四、基礎用法

1、實體類

通過Document和Field注解描述ES索引結構的實體類，注意這里JsonIgnoreProperties注解，解決索引中字段和實體類非一一對應的而引起的JSON解析問題；

@JsonIgnoreProperties(ignoreUnknown = true)
@Document(indexName = "contents_index", createIndex = false)
public class ContentsIndex implements Serializable {private static final long serialVersionUID=1L;@Field(type= FieldType.Integer)private Integer id;@Field(type= FieldType.Keyword)private String title;@Field(type= FieldType.Keyword)private String intro;@Field(type= FieldType.Text)private String content;@Field(type= FieldType.Integer)private Integer createId;@Field(type= FieldType.Keyword)private String createName;@Field(type= FieldType.Date,format = DateFormat.date_hour_minute_second)private Date createTime;
}

2、初始化索引

基于ElasticsearchTemplate類和上述實體類，實現索引結構的初始化，并且將tb_contents表中的數據同步到索引中，最后通過ID查詢一條測試數據；

@Service
public class ContentsIndexService {private static final Logger log = LoggerFactory.getLogger(ContentsIndexService.class);@Resourceprivate ContentsService contentsService ;@Resourceprivate ElasticsearchTemplate template ;/*** 初始化索引結構和數據*/public void initIndex (){// 處理索引結構IndexOperations indexOps = template.indexOps(ContentsIndex.class);if (indexOps.exists()){boolean delFlag = indexOps.delete();log.info("contents_index exists，delete:{}",delFlag);indexOps.createMapping(ContentsIndex.class);} else {log.info("contents_index not exists");indexOps.createMapping(ContentsIndex.class);}// 同步數據庫表記錄List<Contents> contentsList = contentsService.queryAll();if (contentsList.size() > 0){List<ContentsIndex> contentsIndexList = new ArrayList<>() ;contentsList.forEach(contents -> {ContentsIndex contentsIndex = new ContentsIndex() ;BeanUtils.copyProperties(contents,contentsIndex);contentsIndexList.add(contentsIndex);});template.save(contentsIndexList);}// ID查詢ContentsIndex contentsIndex = template.get("10",ContentsIndex.class);log.info("contents-index-10:{}",contentsIndex);}
}

3、倉儲接口

繼承ElasticsearchRepository接口，可以對ES這種特定類型的存儲庫進行通用增刪改查操作；在測試類中對該接口的方法進行測試；

// 1、接口定義
public interface ContentsIndexRepository extends ElasticsearchRepository<ContentsIndex,Long> {
}// 2、接口測試
public class ContentsIndexRepositoryTest {@Autowiredprivate ContentsIndexRepository contentsIndexRepository;@Testpublic void testAdd (){// 單個新增contentsIndexRepository.save(buildOne());// 批量新增contentsIndexRepository.saveAll(buildList()) ;}@Testpublic void testUpdate (){// 根據ID查詢后再更新Optional<ContentsIndex> contentsOpt = contentsIndexRepository.findById(14L);if (contentsOpt.isPresent()){ContentsIndex contentsId = contentsOpt.get();System.out.println("id=14:"+contentsId);contentsId.setContent("update-content");contentsId.setCreateTime(new Date());contentsIndexRepository.save(contentsId);}}@Testpublic void testQuery (){// 單個ID查詢Optional<ContentsIndex> contentsOpt = contentsIndexRepository.findById(1L);if (contentsOpt.isPresent()){ContentsIndex contentsId1 = contentsOpt.get();System.out.println("id=1:"+contentsId1);}// 批量ID查詢Iterator<ContentsIndex> contentsIterator = contentsIndexRepository.findAllById(Arrays.asList(10L,12L)).iterator();while (contentsIterator.hasNext()){ContentsIndex contentsIndex = contentsIterator.next();System.out.println("id="+contentsIndex.getId()+":"+contentsIndex);}}@Testpublic void testDelete (){contentsIndexRepository.deleteById(15L);contentsIndexRepository.deleteById(16L);}
}

4、查詢語法

無論是ElasticsearchTemplate類還是ElasticsearchRepository接口，都是對ES常用的簡單功能進行封裝，在實際使用時，復雜的查詢語法還是依賴ElasticsearchClient和原生的API封裝；

這里主要演示七個查詢方法，主要涉及：ID查詢，字段匹配，組合與范圍查詢，分頁與排序，分組統計，最大值查詢和模糊匹配；更多的查詢API還是要多看文檔中的案例才行；

public class ElasticsearchClientTest {@Autowiredprivate ElasticsearchClient client ;@Testpublic void testSearch1 () throws IOException {// ID查詢GetResponse<ContentsIndex> resp = client.get(getReq ->getReq.index("contents_index").id("7"), ContentsIndex.class);if (resp.found()){ContentsIndex contentsIndex = resp.source() ;System.out.println("contentsIndex-7："+contentsIndex);}}@Testpublic void testSearch2 () throws IOException {// 指定字段匹配SearchResponse<ContentsIndex> resp = client.search(searchReq -> searchReq.index("contents_index").query(query -> query.match(field -> field.field("createName").query("張三"))),ContentsIndex.class);printResp(resp);}@Testpublic void testSearch3 () throws IOException {// 組合查詢：姓名和時間范圍Query byName = MatchQuery.of(field -> field.field("createName").query("王五"))._toQuery();Query byTime = RangeQuery.of(field -> field.field("createTime").gte(JsonData.of("2023-07-10T00:00:00")).lte(JsonData.of("2023-07-12T00:00:00")))._toQuery();SearchResponse<ContentsIndex> resp = client.search(searchReq -> searchReq.index("contents_index").query(query -> query.bool(boolQuery -> boolQuery.must(byName).must(byTime))),ContentsIndex.class);printResp(resp);}@Testpublic void testSearch4 () throws IOException {// 排序和分頁，在14條數據中，根據ID倒序排列，從第5條往后取4條數據SearchResponse<ContentsIndex> resp = client.search(searchReq -> searchReq.index("contents_index").from(5).size(4).sort(sort -> sort.field(sortField -> sortField.field("id").order(SortOrder.Desc))),ContentsIndex.class);printResp(resp);}@Testpublic void testSearch5 () throws IOException {// 根據createId分組統計SearchResponse<ContentsIndex> resp = client.search(searchReq -> searchReq.index("contents_index").aggregations("createIdGroup",agg -> agg.terms(term -> term.field("createId"))),ContentsIndex.class);Aggregate aggregate = resp.aggregations().get("createIdGroup");LongTermsAggregate termsAggregate = aggregate.lterms();Buckets<LongTermsBucket> buckets = termsAggregate.buckets();for (LongTermsBucket termsBucket : buckets.array()) {System.out.println(termsBucket.key() + " : " + termsBucket.docCount());}}@Testpublic void testSearch6 () throws IOException {// 查詢最大的IDSearchResponse<ContentsIndex> resp = client.search(searchReq -> searchReq.index("contents_index").aggregations("maxId",agg -> agg.max(field -> field.field("id"))),ContentsIndex.class);for (Map.Entry<String, Aggregate> entry : resp.aggregations().entrySet()){System.out.println(entry.getKey()+":"+entry.getValue().max().value());}}@Testpublic void testSearch7 () throws IOException {// 模糊查詢title字段，允許1個誤差Query byContent = FuzzyQuery.of(field -> field.field("title").value("設計").fuzziness("1"))._toQuery();SearchResponse<ContentsIndex> resp = client.search(searchReq -> searchReq.index("contents_index").query(byContent),ContentsIndex.class);printResp(resp);}private void printResp (SearchResponse<ContentsIndex> resp){TotalHits total = resp.hits().total();System.out.println("total："+total);List<Hit<ContentsIndex>> hits = resp.hits().hits();for (Hit<ContentsIndex> hit: hits) {ContentsIndex contentsIndex = hit.source();System.out.println(hit.id()+"："+contentsIndex);}}
}

五、參考源碼

文檔倉庫：
https://gitee.com/cicadasmile/butte-java-note源碼倉庫：
https://gitee.com/cicadasmile/butte-spring-parent