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【Elasticsearch 自学笔记三】Spring Boot 整合 ES

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本文介绍了 Spring Boot 整合 Elasticsearch 的方法，包括索引操作、字段操作、复杂搜索、分页与排序、使用 @Query、使用 NativeQuery。

这一期我们用 Spring Boot + Spring Data Elasticsearch 整合 ES.

导入依赖

选用 Idea 快速创建 Spring Boot 项目，选择：

  • Spring Data Elasticsearch
  • Lombok
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<!-- Spring Data Elasticsearch -->
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
</dependency>

<!-- Spring Web -->
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<!-- Spring Development -->
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-devtools</artifactId>
  <scope>runtime</scope>
  <optional>true</optional>
</dependency>
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-configuration-processor</artifactId>
  <optional>true</optional>
</dependency>

<!-- Lombok -->
<dependency>
  <groupId>org.projectlombok</groupId>
  <artifactId>lombok</artifactId>
  <optional>true</optional>
</dependency>

<!-- Spring Test -->
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-test</artifactId>
  <scope>test</scope>
  <exclusions>
    <exclusion>
      <groupId>org.junit.vintage</groupId>
      <artifactId>junit-vintage-engine</artifactId>
    </exclusion>
  </exclusions>
</dependency>

编写配置

不写也可以，因为这本来就是默认值。

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spring.elasticsearch.rest.uris=http://127.0.0.1:9200

索引操作

到这里，我们就可以操作索引了。

通过 Autowired 自动注入 ElasticsearchRestTemplate 类，这里演示索引的创建、查看和删除：

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@Autowired
private ElasticsearchRestTemplate elasticsearchRestTemplate;

@Test
public void testCreateIndex() {
  boolean isSuccess = elasticsearchRestTemplate.indexOps(IndexCoordinates.of("user")).create();
  System.out.println(isSuccess);
}

@Test
public void testGetIndex() {
  Map<String, Object> map = elasticsearchRestTemplate.indexOps(IndexCoordinates.of("user")).getMapping();
  for (Map.Entry<String, Object> entry : map.entrySet()) {
    System.out.println(entry.getKey() + ": " + entry.getValue());
  }
}

@Test
public void testDeleteIndex() {
  boolean isSuccess = elasticsearchRestTemplate.indexOps(IndexCoordinates.of("user")).delete();
  System.out.println(isSuccess);
}

字段操作

创建实体类

@Document 指定索引名

@Field 指定字段类型，store 指定字段是否保存，analzyer 指定分词器。

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@NoArgsConstructor
@Getter
@Setter
@Accessors(chain = true)
@Document(indexName = "user")
public class User {

  @Id
  @Field(type = FieldType.Integer, store = true)
  private String id;

  @Field(type = FieldType.Keyword, store = true)
  private String name;

  @Field(type = FieldType.Integer, store = true)
  private int age;

  @Field(type = FieldType.Text, store = true, analyzer = "ik_max_word")
  private String desc;

  @Override
  public String toString() {
    return "Name: " + name + ", age: " + age + ", description: " + desc + ".";
  }

}

此处 ID 使用 String 类型，是因为当我们不指定 ID 时，String = null，ES 会自动生成随机 ID.

创建接口

Spring Data 系列的一贯传统，声明接口方法，自动通过动态代理实现。

至于接口方法的命名规则，可以查看我之前的 Spring Data JPA 笔记。

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public interface UserDao extends ElasticsearchRepository<User, String> {
  List<User> findByDescMatches(String key);
}

调用接口方法

我们来写一个 Service：

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public interface ElasticsearchService {

  void addUser(User user) throws IOException;

  void addUserList(List<User> list);

  List<User> searchUserByDesc(String desc) throws IOException;

}

实现类：

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package org.koorye.service;

import org.koorye.dao.UserDao;
import org.koorye.entity.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class ElasticsearchServiceImpl implements ElasticsearchService {

  @Autowired
  private UserDao userDao;

  @Override
  public void addUser(User user) {
    userDao.save(user);
  }

  @Override
  public void addUserList(List<User> list) {
    userDao.saveAll(list);
  }

  @Override
  public List<User> searchUserByDesc(String key) {
    return userDao.findByDescMatches(key);
  }

}

非常简单，一行代码就可以解决一个方法。

测试：

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@Test
public void testAddUser() {
  List<User> userList = new ArrayList<>();
  userList.add(new User().setName("koorye1").setAge(19).setDesc("I love python"));
  userList.add(new User().setName("koorye2").setAge(20).setDesc("I love java"));
  userList.add(new User().setName("koorye3").setAge(21).setDesc("I love c"));
  elasticsearchService.addUserList(userList);
}

@Test
public void testSearchUserByDesc() {
  String matchKey = "love";
  List<User> list = elasticsearchService.searchUserByDesc(matchKey);
  for (User user : list) {
    System.out.println(user);
  }
}

返回结果：

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Name: koorye1, age: 19, description: I love python.
Name: koorye2, age: 20, description: I love java.
Name: koorye3, age: 21, description: I love c.

复杂搜索

Spring Data Elasticsearch 的方法命名匹配使得我们执行复杂搜索变得异常简单。

官方文档的示例：

关键词 示例
And findByNameANdPrice
Or findByNameOrPrice
Is findByName
Not findByNameNot
Between findByPriceBetween
LessThan findByPriceLessThan
LessThanEqual findByPriceLessThanEqual
GreaterThan findByPriceGreaterThan
GreaterThanEqual findByPriceGreaterThanEqual
Before findByPriceBefore
After findByPriceAfter
Like findByNameLike
StartingWith findByNameStartingWith
EndingWith findByNameEndingWith
Contains/Containing findByNameContaining
In findByNameIn(Collection<String> names)
NotIn findByNameNotIn(Collection<String> names)
Near findByStoreNear(暂不支持？)
True findByAvailableTrue
False findByAvailableFalse
OrderBy findByAvailableTrueOrderByNameDesc

借助这些关键词，布尔查询、区间查询就可以非常方便的实现。

结果分页与排序

只需在参数中加入 Pageable 和 Sort 就可以实现，当然排序也可以使用 OrderBy ：

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public interface ElasticsearchService {

  void addUser(User user) throws IOException;

  void addUserList(List<User> list);

  List<User> searchUserByDesc(String desc) throws IOException;

  List<User> searchUserByDescOrderByAge(String desc);

  List<User> searchUserByDesc(String desc, Sort sort);

  Page<User> searchUserByDesc(String desc, Pageable pageable) throws IOException;

}

Service 层代码就不再演示。

测试：

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@Test
public void testSearchUserBySort() {
  String key = "love";
  Sort sort = Sort.by(Sort.Direction.DESC, "age");
  List<User> userList = elasticsearchService.searchUserByDesc(key, sort);
  for (User user : userList) {
    System.out.println(user);
  }
}

@Test
public void testSearchUserByOrder() {
  String key = "love";
  List<User> userList = elasticsearchService.searchUserByDescOrderByAge(key);
  for (User user : userList) {
    System.out.println(user);
  }
}

@Test
public void testSearchUserByDescPageable() {
  String matchKey = "love";
  Pageable pageable = PageRequest.of(0, 2);
  Page<User> userPage = elasticsearchService.searchUserByDesc(matchKey, pageable);
  List<User> userList = userPage.getContent();
  for (User user : userList) {
    System.out.println(user);
  }
}

返回结果：

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Name: koorye3, age: 21, description: I love c.
Name: koorye3, age: 21, description: I love c.
Name: koorye2, age: 20, description: I love java.
Name: koorye2, age: 20, description: I love java.
Name: koorye1, age: 19, description: I love python.
Name: koorye1, age: 19, description: I love python.
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Name: koorye3, age: 21, description: I love c.
Name: koorye3, age: 21, description: I love c.
Name: koorye2, age: 20, description: I love java.
Name: koorye2, age: 20, description: I love java.
Name: koorye1, age: 19, description: I love python.
Name: koorye1, age: 19, description: I love python.
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Name: koorye1, age: 19, description: I love python.
Name: koorye2, age: 20, description: I love java.

使用 @Query

@Query 注解使得我们可以使用 JSON 编写条件：

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@Query("{\"match\": {\"desc\": \"love\"}}")
List<User> searchUserByQuery();

测试：

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@Test
public void testSearchUserByQuery() {
  List<User> userList = elasticsearchService.searchUserByQuery();
  for (User user : userList) {
    System.out.println(user);
  }
}

返回结果：

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Name: koorye1, age: 19, description: I love python.
Name: koorye2, age: 20, description: I love java.
Name: koorye3, age: 21, description: I love c.
Name: koorye1, age: 19, description: I love python.
Name: koorye2, age: 20, description: I love java.
Name: koorye3, age: 21, description: I love c.

使用 NativeQuery

相当于原生的查询，我们可以指定很多复杂条件，如过滤、分页、排序、高亮等：

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@Test
public void testSearchUserByNativeQuery() {
  NativeSearchQuery nativeSearchQuery = new NativeSearchQueryBuilder().withFields("name", "age")
      .withQuery(QueryBuilders.matchQuery("desc", "love"))
      .withPageable(PageRequest.of(0, 3))
      .withSort(SortBuilders.fieldSort("age").order(SortOrder.DESC))
      .withHighlightFields(new HighlightBuilder.Field("desc"))
      .build();

  List<User> userList = elasticsearchRestTemplate.queryForList(nativeSearchQuery, User.class, IndexCoordinates.of("user"));

  for (User user : userList) {
    System.out.println(user);
  }
}

返回结果：

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Name: koorye3, age: 21, description: null.
Name: koorye3, age: 21, description: null.
Name: koorye2, age: 20, description: null.

最新版本中 NativeQuery 已被弃用？