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Elasticsearch 应用开发指南

1. 引入 POM 依赖

在项目根目录的 pom.xml 中添加必要的依赖，确保能够正常使用 Elasticsearch。

   
    
    
     org.springframework.boot
    
    
    
     spring-boot-starter-parent
    
    
    
     2.3.2.RELEASE
    
   
   
    
    
    
    
        
     
      org.springframework.boot
     
        
     
      spring-boot-starter-data-elasticsearch
     
    
    
    
    
    
    
    
        
     
      org.springframework.boot
     
        
     
      spring-boot-starter-web
     
    
    
    
    
    
    
    
        
     
      cn.hutool
     
        
     
      hutool-core
     
        
     
      5.7.13
     
    
    
    
    
    
    
    
        
     
      org.projectlombok
     
        
     
      lombok
     
    
    
    
    
    
    
    
        
     
      org.springframework.boot
     
        
     
      spring-boot-starter-test
     
    
    
    
    
        
     
      junit
     
        
     
      junit
     
    
    
   

2. 应用配置

在 application.properties 中配置 Elasticsearch 的基础设置。

spring:
    elasticsearch:
        rest:
            uris: 127.0.0.1:9200
            username: 
            password: 
            connection-timeout: 1000
            read-timeout: 1000

3. JavaBean 配置及 ES 注解

使用 Spring Data Elasticsearch 注解来定义索引和字段映射。

常用数据类型

• 简单类型:
  • text: 分词字段，支持聚合
  • keyword: 不分词字段，支持聚合
  • date: 日期类型
  • boolean: 布尔值
• 复杂类型:
  • Nested: 嵌套对象
  • Object: JSON 对象
  • Array: 数组
  • List: 列表

Student 实体类

import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.Document;
import org.springframework.data.elasticsearch.annotations.Field;
import java.util.Date;
import java.util.List;
@Data
@NoArgsConstructor
@AllArgsConstructor
@Document(indexName = "student", type = "_doc", replicas = 1, shards = 1, createIndex = true)
public class Student {
    @Id
    @Field(index = true, store = true, type = FieldType.Keyword)
    private String sId;
    
    @Field(index = true, store = true, type = FieldType.Keyword)
    private String sName;
    
    @Field(index = true, store = true, type = FieldType.Text, analyzer = "ik_smart")
    private String sAddress;
    
    @Field(index = false, store = true, type = FieldType.Integer)
    private Integer sAge;
    
    @Field(index = false, store = true, type = FieldType.Date, format = DateFormat.basic_date_time)
    private Date sCreateTime;
    
    @Field(index = false, store = true, type = FieldType.Object)
    private Headmaster sHeadmaster;
    
    @Field(index = true, store = false, type = FieldType.Keyword)
    private String[] sCourseList;
    
    @Field(index = true, store = false, type = FieldType.Keyword)
    private List
   
     sColorList;
    
    @Field(index = true, store = false, type = FieldType.Nested)
    private List
    
      sTeacherList;
}
    
   

4. 启动类配置

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class ElasticsearchApplication {
    public static void main(String[] args) {
        SpringApplication.run(ElasticsearchApplication.class, args);
    }
}

5. ElasticsearchRestTemplate 新增

5.1 createIndex & putMapping

通过 RestTemplate 创建索引及映射。

import org.springframework.data.elasticsearch.core.ElasticsearchRestTemplate;
@Service
public class ElasticsearchSaveService {
    @Autowired
    private ElasticsearchRestTemplate elasticsearchRestTemplate;
    
    public boolean createIndexAndMapping(Class
    classType) {
        return elasticsearchRestTemplate.indexExists(classType) 
               && elasticsearchRestTemplate.createIndex(classType)
               && elasticsearchRestTemplate.putMapping(classType);
    }
}

5.2 save 添加文档

通过 RestTemplate 批量或单独添加文档。

import org.springframework.data.elasticsearch.core.ElasticsearchRestTemplate;
@Service
public class ElasticsearchSaveService {
    @Autowired
    private ElasticsearchRestTemplate elasticsearchRestTemplate;
    
    public Iterable
   
     save(Iterable
    
      entities) {
        return elasticsearchRestTemplate.save(entities);
    }
    
    public T save(T entity) {
        return elasticsearchRestTemplate.save(entity);
    }
}
    
   

6. ElasticsearchRestTemplate 删除

6.1 deleteIndex

通过 RestTemplate 删除索引。

import org.springframework.data.elasticsearch.core.ElasticsearchRestTemplate;
@Service
public class ElasticsearchDeleteService {
    @Autowired
    private ElasticsearchRestTemplate elasticsearchRestTemplate;
    
    public boolean deleteIndex(Class
    clazz) {
        return elasticsearchRestTemplate.deleteIndex(clazz);
    }
}

6.2 delete 删除文档

通过 RestTemplate 删除文档。

import org.springframework.data.elasticsearch.core.ElasticsearchRestTemplate;
@Service
public class ElasticsearchDeleteService {
    @Autowired
    private ElasticsearchRestTemplate elasticsearchRestTemplate;
    
    public Boolean delete(String id, Class
    entityType) {
        return elasticsearchRestTemplate.delete(id, entityType);
    }
    
    public Boolean delete(Object entity) {
        return elasticsearchRestTemplate.delete(entity);
    }
}

7. 搜索功能

通过 RestTemplate 执行复杂查询。

import org.springframework.data.elasticsearch.core.query.Query;
import org.springframework.data.elasticsearch.core.ElasticsearchRestTemplate;
@Service
public class ElasticsearchQueryService {
    @Autowired
    private ElasticsearchRestTemplate elasticsearchRestTemplate;
    
    public List
   
     search(Query query) {
        return elasticsearchRestTemplate.query(query, T.class);
    }
}
   

8. 搜索优化

• 分词器设置: 使用 ik_smart 或 ik_max_word 分词器。
• 日期格式: 建议使用标准日期格式。
• 聚合操作: 合理使用聚合操作，避免过度聚合。

通过以上配置和操作，可以实现对 Elasticsearch 的高效管理和文档存储。