SpringBoot2.x集成分布式搜索引擎Elasticsearch

深藏阁楼爱情的钟 2022-12-18 03:57 157阅读 0赞

参考资料：

[https://my.oschina.net/uwith/blog/3226665][https_my.oschina.net_uwith_blog_3226665]

[https://www.freesion.com/article/8399663484/][https_www.freesion.com_article_8399663484]

[https://cloud.tencent.com/developer/article/1529654][https_cloud.tencent.com_developer_article_1529654]

[https://zhuyc.vip/archives/2020043013343102208][https_zhuyc.vip_archives_2020043013343102208]

elasticsearchResttemplate注入：[https://www.jianshu.com/p/bc54cf93bfd2][https_www.jianshu.com_p_bc54cf93bfd2]

7+版本后，index、type、document：[https://www.letianbiji.com/elasticsearch/es7-index-type-doc.html][https_www.letianbiji.com_elasticsearch_es7-index-type-doc.html]

## 1. 前言 ##

在工作中你或多或少听说过搜索引擎，目前最流行的搜索引擎就是Elasticsearch，本文将从Elasticsearch的安装、实战、原理分析几个方面带你领略Elasticsearch的风采

## 2. Elasticsearch介绍 ##

Elasticsearch是一个分布式搜索引擎，可以用来存储、分析、搜索数据。

## 3. Elasticsearch安装 ##

### 3.1 Docker的方式安装Elasticsearch ###

3.1.1 使用docker搜索镜像

➜  ~ docker search elasticsearch

3.1.2从远程拉取镜像

➜  ~ docker pull elasticsearch:7.4.0

3.1.3 启动镜像

➜  ~ docker run -d --name myes -p 9200:9200 -p 9300:9300 -e "discovery.type=single-node" elasticsearch:7.4.0

3.1.4 访问Elasticsearch

http://localhost:9200/

{
      "name" : "0222e17f062d",
      "cluster_name" : "docker-cluster",
      "cluster_uuid" : "OtL-k7FpR4ylPVsiKcZIkA",
      "version" : {
        "number" : "7.4.0",
        "build_flavor" : "default",
        "build_type" : "docker",
        "build_hash" : "22e1767283e61a198cb4db791ea66e3f11ab9910",
        "build_date" : "2019-09-27T08:36:48.569419Z",
        "build_snapshot" : false,
        "lucene_version" : "8.2.0",
        "minimum_wire_compatibility_version" : "6.8.0",
        "minimum_index_compatibility_version" : "6.0.0-beta1"
      },
      "tagline" : "You Know, for Search"
    }

当你看到如上返回数据，恭喜你es安装成功了。

### 3.2 正常安装Elasticsearch ###

3.2.1 下载安装包

Linux：

➜  ~ curl -L -O https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-7.4.1-linux-x86_64.tar.gz

MacOS：

➜  ~ wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-7.4.1-darwin-x86_64.tar.gz

3.2.2 解压安装包

Linux:

➜  ~ tar -xvf elasticsearch-7.4.1-linux-x86_64.tar.gz

macOS:

➜  ~ tar -xvf elasticsearch-7.4.1-darwin-x86_64.tar.gz

3.2.3 运行

Linux and macOS:

➜  ~ cd elasticsearch-7.4.1/bin
    ➜  ~ ./elasticsearch

### 3.3 访问Elasticsearch ###

http://localhost:9200/

## 4.Elasticsearch增、删、改、查实战 ##

本文以SpringBoot整合Elasticsearch进行实战讲解，要求对SpringBoot有一定的了解

### 4.1 新建项目 ###

创建boot-example-elasticsearch模块

### 4.2 添加依赖 ###

<dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
            </dependency>
        </dependencies>

### 4.3 配置Elasticsearch地址 ###

spring:
      elasticsearch:
        rest:
          uris: http://localhost:9200 # 指明es地址
    复制代码

### 4.4 创建文档实体类 ###

@Data
    @Builder
    @NoArgsConstructor
    @AllArgsConstructor
    @ToString
    @Document(indexName = "goods", type = "_doc")
    public class Goods implements Serializable {
    
        @Id
        private Long id;
    
        @Field
        private String name;
    
        @Field
        private String title;
    
        @Field
        private BigDecimal price;
    
        @Field
        private String publishDate;
    }

> 需要使用@Document注解用来指明索引和文档类型，这样在操作文档数据的时候可以不需要指定索引和类型。使用@Id注解指明文档的id，@Field用于指明文档的其它属性

### 4.5 注入ElasticsearchRestTemplate ###

和往常操作其它中间件如redis、rabbitMQ一样，需要注入相应的xxxxTemplate

@Autowired
    private ElasticsearchRestTemplate elasticsearchRestTemplate;

### 4.6 新增文档数据 ###

@Test
    public void insert() {
        Goods goods = Goods.builder()
            .id(10006L)
            .name("测试商品")
            .title("我是一个测试商品，拍了不发货，请谨慎！")
            .price(new BigDecimal(9999999))
            .publishDate("2019-11-06")
            .build();
        /**
             * index用于新增或者修改整个文档
             * 文档不存在，执行新增操作
             * 文档存在，执行修改操作
             * 此处只需要设置索引的对象即可，底层代码会从索引对象的@Document注解中获取索引、类型以及文档的id
             */
        elasticsearchRestTemplate.index(new IndexQueryBuilder().withObject(goods).build());
        log.info("index document finish");
    }

### 4.7 批量新增文档数据 ###

@Test
    public void batchInsert() {
        List<Goods> goodsList = buildGoodsList();
        List<IndexQuery> indexQueryList = new ArrayList<>();
        for (int i = 0, len = goodsList.size(); i < len; i++) {
            indexQueryList.add(new IndexQueryBuilder()
                               .withObject(goodsList.get(i)).build());
        }
        // 使用bulk方法批量索引文档
        elasticsearchRestTemplate.bulkIndex(indexQueryList);
        log.info("batch index document finish");
    }

### 4.8 修改文档数据 ###

@Test
    public void update() {
        Goods goods = Goods.builder()
            .id(10001L)
            .name("AppleiPhone 11 update")
            .title("Apple iPhone 11 (A2223) 64GB 黑色 移动联通电信4G手机 双卡双待 update")
            .price(new BigDecimal(6666))
            .publishDate("2019-12-12")
            .build();
        IndexQuery indexQuery = new IndexQueryBuilder()
            .withObject(goods)
            .build();
        /**
             * 使用index方法来更新整个文档
             * 如果有字段为null，更新到es中，es文档中不会有该字段存在
             * {
             *           "_class" : "com.boot.example.Goods",
             *           "id" : 10006,
             *           "name" : "AppleiPhone 11 update",
             *           "title" : "Apple iPhone 11 (A2223) 64GB 黑色 移动联通电信4G手机 双卡双待 update"
             *         }
             */
        elasticsearchRestTemplate.index(indexQuery);
        log.info("update document");
    }

### 4.9 修改文档部分数据 ###

@Test
    public void partialUpdate() {
        // 构建需要更新的字段
        Map<String, Object> map = new HashMap<>();
        map.put("price", new BigDecimal(6666));
        map.put("publishDate", "2019-09-08");
        UpdateQuery updateQuery = new UpdateQueryBuilder()
            .withId("10001")
            .withClass(Goods.class)
            .withUpdateRequest(new UpdateRequest().doc(map))
            .build();
        // 更新文档的部分内容
        elasticsearchRestTemplate.update(updateQuery);
        log.info("partial update document");
    }

### 4.10 查询单个文档数据 ###

@Test
    public void getById() {
        GetQuery getQuery = new GetQuery();
        getQuery.setId("10001");
        Goods goods = elasticsearchRestTemplate.queryForObject(getQuery, Goods.class);
        log.info("get document by id result：{}", goods);
    }

### 4.11 查询文档列表数据 ###

@Test
    public void list() {
        /**
             * 使用match进行搜索
             * GET /goods/_search
             * {
             *   "query": {
             *     "match": {
             *       "title": "apple"
             *     }
             *   }
             * }
             */
        NativeSearchQuery nativeSearchQuery = new NativeSearchQueryBuilder()
            .withQuery(new MatchQueryBuilder("title", "apple"))
            .withSort(new FieldSortBuilder("publishDate").order(SortOrder.DESC))
            .build();
        List<Goods> goodsList = elasticsearchRestTemplate.queryForList(nativeSearchQuery, Goods.class);
        log.info("list document size：{}， result ：{}", goodsList.size(), goodsList);
    }

### 4.12 多条件查询文档列表数据 ###

@Test
    public void listByMultiCondition() {
        NativeSearchQuery nativeSearchQuery = new NativeSearchQueryBuilder()
            .withQuery(new BoolQueryBuilder()
                       .must(new MatchQueryBuilder("title", "apple"))
                       .must(new RangeQueryBuilder("price").from(BigDecimal.ZERO).to(new BigDecimal(12800)))
                      )
            .build();
        List<Goods> goodsList = elasticsearchRestTemplate.queryForList(nativeSearchQuery, Goods.class);
        log.info("list document size：{}， result ：{}", goodsList.size(), goodsList);
    }

### 4.13 分页查询文档数据 ###

@Test
    public void page() {
        QueryBuilder queryBuilder = new MatchQueryBuilder("title", "apple");
        NativeSearchQuery nativeSearchQuery = new NativeSearchQueryBuilder()
            .withQuery(queryBuilder)
            .withPageable(PageRequest.of(0, 10))
            .build();
        /**
             * 查看详细的请求响应日志信息，在配置文件中设置如下：
             * logging:
             *   level:
             *     tracer: trace
             *
             *     2019-11-06 21:09:11.995 TRACE 13584 --- [/O dispatcher 1] tracer: curl -iX POST 'http://localhost:9200/goods/_doc/_search?rest_total_hits_as_int=true&typed_keys=true&ignore_unavailable=false&expand_wildcards=open&allow_no_indices=true&ignore_throttled=true&search_type=dfs_query_then_fetch&batched_reduce_size=512' -d '{"from":0,"size":10,"query":{"match":{"title":{"query":"apple","operator":"OR","prefix_length":0,"max_expansions":50,"fuzzy_transpositions":true,"lenient":false,"zero_terms_query":"NONE","auto_generate_synonyms_phrase_query":true,"boost":1.0}}},"version":true}'
             *     # HTTP/1.1 200 OK
             *     # Warning: 299 Elasticsearch-7.4.0-22e1767283e61a198cb4db791ea66e3f11ab9910 "[types removal] Specifying types in search requests is deprecated."
             *     # content-type: application/json; charset=UTF-8
             *     # content-length: 730
             *     #
             *     # {"took":0,"timed_out":false,"_shards":{"total":1,"successful":1,"skipped":0,"failed":0},"hits":{"total":2,"max_score":0.76022595,"hits":[{"_index":"goods","_type":"_doc","_id":"10001","_version":2,"_score":0.76022595,"_source":{"_class":"com.boot.example.Goods","id":10001,"name":"AppleiPhone 11","title":"Apple iPhone 11 (A2223) 64GB 黑色 移动联通电信4G手机 双卡双待","price":6666,"publishDate":"2019-09-08"}},{"_index":"goods","_type":"_doc","_id":"10002","_version":1,"_score":0.73438257,"_source":{"_class":"com.boot.example.Goods","id":10002,"name":"AppleMNYH2CH/A","title":"Apple MacBook 12 | Core m3 8G 256G SSD硬盘 银色 笔记本电脑 轻薄本 MNYH2CH/A","price":12800.0,"publishDate":"2018-09-11"}}]}}
             */
        Page<Goods> page = elasticsearchRestTemplate.queryForPage(nativeSearchQuery, Goods.class);
        List<Goods> goodsList = page.getContent();
        log.info("page document size：{}，result：{}", goodsList.size(), goodsList);
    }

### 4.14 删除文档 ###

@Test
    public void delete() {
        // 删除文档
        elasticsearchRestTemplate.delete(Goods.class, "10001");
    }

## 5.Elasticsearch聚合实战 ##

### 5.1 统计文档数量 ###

@Test
    public void count() {
        SearchQuery searchQuery = new NativeSearchQueryBuilder().build();
        Long count = elasticsearchRestTemplate.count(searchQuery, Goods.class);
        log.info("goods count：{}", count);
    }

### 5.2 求平均值 ###

@Test
    public void avgPrice() {
        SearchQuery searchQuery = new NativeSearchQueryBuilder()
            .addAggregation(AggregationBuilders.avg("avg_price").field("price"))
            .withIndices("goods")
            .build();
        double avgPrice = elasticsearchRestTemplate.query(searchQuery, response -> {
            Avg avg = response.getAggregations().get("avg_price");
            return avg.getValue();
        });
        log.info("avg_price：{}", avgPrice);
    }

### 5.3 求最大值 ###

@Test
    public void maxPrice() {
        SearchQuery searchQuery = new NativeSearchQueryBuilder()
            .addAggregation(AggregationBuilders.max("max_price").field("price"))
            .withIndices("goods")
            .build();
        double maxPrice = elasticsearchRestTemplate.query(searchQuery, response -> {
            Max max = response.getAggregations().get("max_price");
            return max.getValue();
        });
        log.info("max_price：{}", maxPrice);
    }

## 6. ElasticsearchRestTemplate API总结 ##

<table> 
 <thead> 
  <tr> 
   <th>序号</th> 
   <th>功能</th> 
   <th>方法名</th> 
   <th>query对象</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>1</td> 
   <td>新增</td> 
   <td>index</td> 
   <td>IndexQuery</td> 
  </tr> 
  <tr> 
   <td>2</td> 
   <td>批量新增</td> 
   <td>bulkIndex</td> 
   <td>IndexQuery</td> 
  </tr> 
  <tr> 
   <td>3</td> 
   <td>修改</td> 
   <td>index</td> 
   <td>IndexQuery</td> 
  </tr> 
  <tr> 
   <td>&nbsp;</td> 
   <td>部分修改</td> 
   <td>update</td> 
   <td>UpdateQuery</td> 
  </tr> 
  <tr> 
   <td>5</td> 
   <td>查询对象</td> 
   <td>queryForObject</td> 
   <td>GetQuery</td> 
  </tr> 
  <tr> 
   <td>6</td> 
   <td>查询列表</td> 
   <td>queryForList</td> 
   <td>NativeSearchQuery</td> 
  </tr> 
  <tr> 
   <td>7</td> 
   <td>分页查询</td> 
   <td>queryForPage</td> 
   <td>NativeSearchQuery</td> 
  </tr> 
  <tr> 
   <td>8</td> 
   <td>删除</td> 
   <td>delete</td> 
   <td>DeleteQuery</td> 
  </tr> 
  <tr> 
   <td>9</td> 
   <td>统计</td> 
   <td>count</td> 
   <td>NativeSearchQuery</td> 
  </tr> 
  <tr> 
   <td>10</td> 
   <td>平均值</td> 
   <td>uery</td> 
   <td>NativeSearchQuery</td> 
  </tr> 
  <tr> 
   <td>11</td> 
   <td>最大值</td> 
   <td>query</td> 
   <td>NativeSearchQuery</td> 
  </tr> 
 </tbody> 
</table>

## 7. SpringBoot整合Elasticsearch原理探秘 ##

### 7.1 ElasticsearchDataConfiguration ###

![ce86d329d1d877c4b2fd23eafa7f7eeb.png][]

声明我们的最重要的ElasticsearchRestTemplate，ElasticsearchRestTemplate需要RestHighLevelClient

### 7.2 RestClientConfigurations ###

![bb7a71e05f63623d12ff8b14574955e7.png][]

声明RestHighLevelClient，RestHighLevelClient需要RestClientBuilder

![e9eb822dcd4e69dd65abbe37858d76bc.png][]

声明RestClientBuilder，RestClientBuilder由RestClient构建得到，构建使用到的hosts从RestClientProperties的uris属性中获取，uris的属性在配置文件中指定

spring:
      elasticsearch:
        rest:
          uris: http://localhost:9200 # 指明es地址
    复制代码

通过本文你不仅学到如何整合SpringBoot和Elasticsearch，还可以通过ElasticsearchRestTemplate对文档进行增、删、改、查操作，最后你还了解了Elasticsearch自动配置原理，希望这些知识对你有帮助。

[https_my.oschina.net_uwith_blog_3226665]: https://my.oschina.net/uwith/blog/3226665
[https_www.freesion.com_article_8399663484]: https://www.freesion.com/article/8399663484/
[https_cloud.tencent.com_developer_article_1529654]: https://cloud.tencent.com/developer/article/1529654
[https_zhuyc.vip_archives_2020043013343102208]: https://zhuyc.vip/archives/2020043013343102208
[https_www.jianshu.com_p_bc54cf93bfd2]: https://www.jianshu.com/p/bc54cf93bfd2
[https_www.letianbiji.com_elasticsearch_es7-index-type-doc.html]: https://www.letianbiji.com/elasticsearch/es7-index-type-doc.html
[ce86d329d1d877c4b2fd23eafa7f7eeb.png]: /images/20221122/1621d928373440788c26ba867e0c782c.png
[bb7a71e05f63623d12ff8b14574955e7.png]: /images/20221122/cefc5d43a26f4520b67581d8aad0f284.png
[e9eb822dcd4e69dd65abbe37858d76bc.png]: /images/20221122/d92f5b94a2cc46c893cc4446b9ab089d.png