spring-boot-learning- Elasticsearch

索引==数据库

类型==表

文档==表里面的记录

属性==表里面的列

使用RestFul风格elasticSearch进行操作

添加一个索引为megacorp,类型为employee,——id为1的文档

获得一个索引：

跟新文档，实际上也是用PUT

注意箭头的地方，每次对文档进行任何操作都会改变版本数

轻量级搜索

_search代替id进行搜索所有

使用查询表达式json格式进行查询

S

Springboot整合ES

先看看我们springboot为我们自动配置了什么

在org.springframework.boot.autoconfigure 自动配置包下的

往下面看一下，会有另外一个elasticsearch的目录，里面：

注：这是另外一种和ES进行交互的工具

#######################################################################################

加入依赖：

 <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
        </dependency>

实体类对应elasticsearch的文档：

@Data
@Document(indexName = "company",type = "employees",shards = 5,replicas = 1)
/**
 * indexName: 索引库名称
 * type:   类型
 * shards:  分片数：默认为5个
 * replicas: 副本数：默认为1个
 */
public class Employe implements Serializable {
    /**
     *用来将对象中id和ES中_id映射
     */
    @Id
    private Long id;
    /**
     * `@Field`: 用来指定ES中的字段对应Mapping,相当于数据库中的列属性
     * ​    `type`: 用来指定ES中存储类型
     */
    @Field(type = FieldType.Text)
    private String name;

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

    @Override
    public String toString() {
        return "Employee{" +
                "id='" + id + '\'' +
                ", name='" + name + '\'' +
                ", password='" + password + '\'' +
                '}';
    }
}

获得操作接口：

/**
 * 直接继承 ElasticsearchRepository接口就可以了，里面已经帮我们实现了
 *
 */
@Repository
public  interface EmployeRepository extends ElasticsearchRepository<Employe,Long> {

}

增删改查

@SpringBootTest
class EsdApplicationTests {

    @Autowired
    private  EmployeRepository employeRepository;

    /**
     * 插入数据：
     */
    @Test
    void testEmploye(){
        Employe employee = new Employe();
        employee.setId(5L);
        employee.setName("zhi");
        employee.setPassword("789");
        employeRepository.save(employee);

    }

    /**
     * 查询数据
     */
    @Test
    void testEmployeGet(){
        Optional<Employe> employe =  employeRepository.findById(2L);
        System.out.println(employe);
    }

    /**
     * 删除数据
     */
    @Test
    void delEmployeDel(){
        employeRepository.deleteById(2L);
    }

    /**
     * 修改数据，实际就是保存数据
     */
    @Test
    void updEmployeUp(){
        Employe employee = new Employe();
        employee.setId(5L);
        employee.setName("zhi");
        employee.setPassword("78955555");
        employeRepository.save(employee);
    }

}

如何取学习一个新的东西：找官方文档：

https://www.elastic.co/guide/index.html

点进去，我们一半使用高级客户端

里面会有详细介绍怎么用：

1 找到原生的依赖:

依赖的其他包：

2 找对象

 3分析类当中的方法

我新建一个工程：

导入依赖：

可以看到：

再进入spring-data里面：

 查看默认的版本：

 注意：我们导入的依赖必须和我们es的版本一致

自定义版本依赖

可以先点进去父pom里面看看

<artifactId>spring-boot-starter-parent</artifactId>

查看一下源码：

加入了这三个类

RestClientConfigurations.RestClientBuilderConfiguration.class,
        RestClientConfigurations.RestHighLevelClientConfiguration.class,
        RestClientConfigurations.RestClientFallbackConfiguration.class 

都是静态内部类

其中关键的类就是RestClientBuilderConfiguration

class RestClientConfigurations {

    @Configuration(proxyBeanMethods = false)
    static class RestClientBuilderConfiguration {

        @Bean
        @ConditionalOnMissingBean
        RestClientBuilder elasticsearchRestClientBuilder(RestClientProperties properties,
                ObjectProvider<RestClientBuilderCustomizer> builderCustomizers) {
            HttpHost[] hosts = properties.getUris().stream().map(HttpHost::create).toArray(HttpHost[]::new);
            RestClientBuilder builder = RestClient.builder(hosts);
            PropertyMapper map = PropertyMapper.get();
            map.from(properties::getUsername).whenHasText().to((username) -> {
                CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
                Credentials credentials = new UsernamePasswordCredentials(properties.getUsername(),
                        properties.getPassword());
                credentialsProvider.setCredentials(AuthScope.ANY, credentials);
                builder.setHttpClientConfigCallback(
                        (httpClientBuilder) -> httpClientBuilder.setDefaultCredentialsProvider(credentialsProvider));
            });
            builder.setRequestConfigCallback((requestConfigBuilder) -> {
                map.from(properties::getConnectionTimeout).whenNonNull().asInt(Duration::toMillis)
                        .to(requestConfigBuilder::setConnectTimeout);
                map.from(properties::getReadTimeout).whenNonNull().asInt(Duration::toMillis)
                        .to(requestConfigBuilder::setSocketTimeout);
                return requestConfigBuilder;
            });
            builderCustomizers.orderedStream().forEach((customizer) -> customizer.customize(builder));
            return builder;
        }

    }

    @Configuration(proxyBeanMethods = false)
    @ConditionalOnClass(RestHighLevelClient.class)
    static class RestHighLevelClientConfiguration {

        @Bean
        @ConditionalOnMissingBean
        RestHighLevelClient elasticsearchRestHighLevelClient(RestClientBuilder restClientBuilder) {
            return new RestHighLevelClient(restClientBuilder);
        }

        @Bean
        @ConditionalOnMissingBean
        RestClient elasticsearchRestClient(RestClientBuilder builder,
                ObjectProvider<RestHighLevelClient> restHighLevelClient) {
            RestHighLevelClient client = restHighLevelClient.getIfUnique();
            if (client != null) {
                return client.getLowLevelClient();
            }
            return builder.build();
        }

    }

    @Configuration(proxyBeanMethods = false)
    static class RestClientFallbackConfiguration {

        @Bean
        @ConditionalOnMissingBean
        RestClient elasticsearchRestClient(RestClientBuilder builder) {
            return builder.build();
        }

    }

}