Spring Boot整合Elasticsearch

Spring Boot整合Elasticsearch是一個相對簡單的過程，可以通過以下步驟來完成：

1. 添加依賴

首先，在你的pom.xml文件中添加Spring Boot和Elasticsearch的依賴。

<dependencies>
    <!-- Spring Boot Starter Data Elasticsearch -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
    </dependency>

    <!-- Elasticsearch Client -->
    <dependency>
        <groupId>org.elasticsearch.client</groupId>
        <artifactId>elasticsearch-java</artifactId>
    </dependency>

    <!-- Spring Boot Starter Web for RESTful services -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
</dependencies>

2. 配置Elasticsearch

在application.properties或application.yml文件中配置Elasticsearch的連接信息。

application.properties

spring.elasticsearch.rest.uris=http://localhost:9200

application.yml

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

3. 創建Elasticsearch Repository

創建一個接口來定義對Elasticsearch的操作。

import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface MyDocumentRepository extends ElasticsearchRepository<MyDocument, String> {
}

4. 創建Elasticsearch實體類

創建一個實體類來映射到Elasticsearch的文檔。

import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.Document;
import org.springframework.data.elasticsearch.annotations.Field;
import org.springframework.data.elasticsearch.annotations.FieldType;

@Document(indexName = "my_documents")
public class MyDocument {

    @Id
    private String id;

    @Field(type = FieldType.Text)
    private String title;

    @Field(type = FieldType.Text)
    private String content;

    // Getters and Setters
}

5. 使用Repository進行操作

在你的服務或控制器中使用MyDocumentRepository進行CRUD操作。

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class MyDocumentService {

    @Autowired
    private MyDocumentRepository repository;

    public MyDocument saveDocument(MyDocument document) {
        return repository.save(document);
    }

    public List<MyDocument> findAllDocuments() {
        return repository.findAll();
    }

    public MyDocument findDocumentById(String id) {
        return repository.findById(id).orElse(null);
    }

    public void deleteDocument(String id) {
        repository.deleteById(id);
    }
}

6. 創建控制器

創建一個控制器來提供RESTful API接口。

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/documents")
public class MyDocumentController {

    @Autowired
    private MyDocumentService service;

    @PostMapping
    public MyDocument saveDocument(@RequestBody MyDocument document) {
        return service.saveDocument(document);
    }

    @GetMapping
    public List<MyDocument> findAllDocuments() {
        return service.findAllDocuments();
    }

    @GetMapping("/{id}")
    public MyDocument findDocumentById(@PathVariable String id) {
        return service.findDocumentById(id);
    }

    @DeleteMapping("/{id}")
    public void deleteDocument(@PathVariable String id) {
        service.deleteDocument(id);
    }
}

7. 啟動應用

啟動你的Spring Boot應用，然后訪問Elasticsearch的REST API來驗證整合是否成功。

curl -X POST "http://localhost:8080/documents" -H 'Content-Type: application/json' -d'
{
    "title": "Sample Document",
    "content": "This is a sample document for Elasticsearch integration."
}'

通過以上步驟，你就可以成功地在Spring Boot應用中整合Elasticsearch，并提供基本的CRUD操作。