Day28：ElasticSearch入门、Spring整合ES、开发社区搜索功能

由于篇幅所限，我将提供ElasticSearch入门和Spring整合ES的核心代码示例。

ElasticSearch入门

安装ElasticSearch并启动服务。

wget -qO - https://artifacts.elastic.co/GPG-KEY-elasticsearch | sudo apt-key add -
sudo apt-get install apt-transport-https
echo "deb https://artifacts.elastic.co/packages/7.x/apt stable main" | sudo tee -a /etc/apt/sources.list.d/elastic-7.x.list
sudo apt-get update && sudo apt-get install elasticsearch
sudo systemctl start elasticsearch.service

Spring整合ES

1. 添加依赖到pom.xml。

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
    </dependency>
    <!-- 其他依赖 -->
</dependencies>

2. 配置application.yml。

spring:
  elasticsearch:
    rest:
      uris: "http://localhost:9200"

3. 创建实体类。

@Document(indexName = "community")
public class DiscussPost {
    @Id
    private int id;
    // 其他属性
}

4. 创建Repository接口。

public interface DiscussPostRepository extends ElasticsearchRepository<DiscussPost, Integer> {
}

5. 使用Repository进行搜索。

@Service
public class SearchService {
    @Autowired
    private DiscussPostRepository discussPostRepository;
 
    public Page<DiscussPost> findDiscussPosts(String keyword, int page, int size) {
        PageRequest pageRequest = PageRequest.of(page, size);
        if (StringUtils.isNotBlank(keyword)) {
            // 使用关键字搜索
            NativeSearchQuery query = new NativeSearchQueryBuilder()
                    .withQuery(QueryBuilders.multiMatchQuery(keyword, "title", "content"))
                    .withPageable(pageRequest)
                    .build();
            return discussPostRepository.search(query);
        } else {
            // 不使用关键字搜索
            return discussPostRepository.findAll(pageRequest);
        }
    }
}

开发社区搜索功能

@Controller
@RequestMapping("/search")
public class SearchController {
    @Autowired
    private SearchService searchService;
 
    @RequestMapping(method = RequestMethod.GET)
    public String getSearchPage(Model model, @RequestParam(name = "keyword", required = false) String keyword,
                               @RequestParam(name = "page", defaultValue = "0") int page,
                               @RequestParam(name = "size", defaultValue