Spring-Boot整合ElasticSearch的简单使用

ゝ一世哀愁。 2023-10-01 02:15 6阅读 0赞

ElasticSearch 是一个分布式搜索服务，提供 Restful API，底层基于 Lucene，采用多 shard（分片）的方式保证数据安全，并提供自动 resharding 的功能

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### ElasticSearch对比MYSQL ###

1.  索引》数据库
2.  类型》表
3.  文档》行
4.  属性》列

### DOCKER创建 ###

// docker 创建 ES 容器
    // -e ES_JAVA_OPTS="-Xms256m -Xmx256m" 限制 ES 内存使用大小
    docker run -e ES_JAVA_OPTS="-Xms256m -Xmx256m" -d -p 9200:9200 -p 9300:9300 --name ES 镜像 id

### 依赖 ###

// spring boot默认使用springData ES模块进行操作
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
    </dependency>

### 配置 ###

spring：
      elasticsearch:
        rest:
          uris: http://localhost:9200
      data:
        elasticsearch:
          repositories:
            enabled: true
          client:
            reactive:
              endpoints: http://localhost:9200

### 实现 ###

@Autowired
    RestHighLevelClient restHighLevelClient ;
    /**
       * 新增单条数据  》》》 转为JSON添加
       * restHighLevelClient.index
     */
    public void saveOne()throws IOException{
        IndexRequest indexRequest =  new IndexRequest("city");
        City city = new City(8,"武汉",0,1);
        indexRequest.id(city.getCid()+"");// 指定ID
        indexRequest.source(JSON.toJSONString(city), XContentType.JSON); // 转换为JSON格式
        // 执行
        restHighLevelClient.index(indexRequest , RequestOptions.DEFAULT);
    }
    
    /**
         * 批量新增  》》》 转为JSON添加
         * restHighLevelClient.bulk
     */
    public void saveAll() throws IOException{
        ArrayList<Object> list = new ArrayList<>();
        BulkRequest bulkRequest = new BulkRequest();
        for (Object o : list) {
            bulkRequest.add(
              new IndexRequest("city")
              .id("") // 指定ID
              .source(JSON.toJSONString(o),XContentType.JSON)      
            );
        }
        restHighLevelClient.bulk(bulkRequest , RequestOptions.DEFAULT);
    }
    
    /**
       * 检索全部
       * QueryBuilders.matchAllQuery()
       * 模糊匹配
       * QueryBuilders.matchQuery("name","zhangsan")
       * 精确匹配
       * QueryBuilders.matchQuery("name.keyword","zhangsan")
       * 区间匹配 （gte 大于等于  lte 小于等于 gt 大于 le 小于）
       * QueryBuilders.rangeQuery("age").gte().lte()
    */
    public void getCity() throws IOException {
        SearchRequest request = new SearchRequest("city");
        SearchSourceBuilder bulider = new SearchSourceBuilder();
        BoolQueryBuilder query = QueryBuilders.boolQuery(); // 组合查询
        query.must(QueryBuilders.matchAllQuery()); // 查找全部
        bulider.query(query);
        
        // 分页
        bulider.from((pageNum-1)*pageSize); // 开始位置
        bulider.size(pageSize); // 显示条数
        
        // 排序  DESC 倒叙  ASC 升序
        bulider.sort("age", SortOrder.DESC);
        
        request.source(bulider);
        SearchResponse search = restHighLevelClient.search(request, RequestOptions.DEFAULT);
        SearchHit[] hits = search.getHits().getHits();
        for (SearchHit hit : hits) {
            String sourceAsString = hit.getSourceAsString();
            System.out.println(sourceAsString);
        }
    }
    
    /**
       * 高亮检索
       * HighlightBuilder
    */
    public void findCity() throws IOException {
        SearchRequest request = new SearchRequest("city");
        SearchSourceBuilder bulider = new SearchSourceBuilder();
        BoolQueryBuilder query = QueryBuilders.boolQuery();
        // 模糊检索
        query.must(QueryBuilders.matchQuery("name","zhang"));
        
        // 高亮
        HighlightBuilder high = new HighlightBuilder();
        high.field("name"); // 添加高亮的字段
        high.preTags("<b>"); // 起始位置
        high.postTags("</b>"); // 结束位置
        bulider.highlighter(high);
        
        bulider.query(query);
        request.source(bulider);
        SearchResponse search = restHighLevelClient.search(request, RequestOptions.DEFAULT);
        SearchHit[] hits = search.getHits().getHits();
        for (SearchHit hit : hits) {
            String sourceAsString = hit.getSourceAsString();
            System.out.println(sourceAsString);
        }
    }

[Elasticsearch官网![icon-default.png_t_M1FB][]https://www.elastic.co/guide/cn/elasticsearch/guide/current/getting-started.html][Elasticsearch_icon-default.png_t_M1FB_https_www.elastic.co_guide_cn_elasticsearch_guide_current_getting-started.html]

[icon-default.png_t_M1FB]: https://csdnimg.cn/release/blog_editor_html/release2.0.5/ckeditor/plugins/CsdnLink/icons/icon-default.png?t=M1FB
[Elasticsearch_icon-default.png_t_M1FB_https_www.elastic.co_guide_cn_elasticsearch_guide_current_getting-started.html]: https://www.elastic.co/guide/cn/elasticsearch/guide/current/getting-started.html