SpringBoot3响应式编程全套-R2DBC
目录
- 传送门
- 前言
- 一、R2DBC概念
- 二、Spring Data R2DBC
- 1、整合
- 1.1、导入依赖
- 1.2、编写配置
- 2、声明式接口:R2dbcRepository
- 2.1、Repository接口
- 2.2、自定义Converter
- 2.3、配置生效
- 3、编程式组件
- 三、RBAC-SQL练习
- 1、1-1
- 2、1-N
- 四、最佳实践
- 五、附录
传送门
SpringMVC的源码解析(精品)
Spring6的源码解析(精品)
SpringBoot3框架(精品)
MyBatis框架(精品)
MyBatis-Plus
SpringDataJPA
SpringCloudNetflix
SpringCloudAlibaba(精品)
Shiro
SpringSecurity
java的LOG日志框架
Activiti(敬请期待)
JDK8新特性
JDK9新特性
JDK10新特性
JDK11新特性
JDK12新特性
JDK13新特性
JDK14新特性
JDK15新特性
JDK16新特性
JDK17新特性
JDK18新特性
JDK19新特性
JDK20新特性
JDK21新特性
其他技术文章传送门入口
前言
由于面试问到的比较多,而且做java开发这块还是需要真正掌握的。
现有笔记尚硅谷雷锋阳老师的:SpringBoot3全栈指南,是我目前见过的最好笔记了。
参考视频尚硅谷雷锋阳老师的:SpringBoot零基础教程,面试&加薪必会,视频是24小时31分钟的高质量教程。
参考代码:https://gitee.com/leifengyang/spring-boot-3
最经典的20个Spring Boot面试题,95%以上会被问到,不服来战
为了防止雷锋阳老师的日志查看不到,这里分类整理一下。下面文章不定时更新
SpringBoot3核心特性-快速入门
SpringBoot3核心特性-Web开发
SpringBoot3核心特性-数据访问
SpringBoot3核心特性-基础特性
SpringBoot3核心特性-核心原理
SpringBoot3场景整合
SpringBoot3响应式编程全套-Reactor核心
SpringBoot3响应式编程全套-Spring Webflux
SpringBoot3响应式编程全套-R2DBC
SpringBoot3响应式编程全套-Spring Security Reactive
一、R2DBC概念
Web、网络、IO(存储)、中间件(Redis、MySQL)
应用开发:
● 网络
● 存储:MySQL、Redis
● Web:Webflux
● 前端; 后端:Controller – Service – Dao(r2dbc;mysql)
数据库:
● 导入驱动; 以前:JDBC(jdbc、各大驱动mysql-connector); 现在:r2dbc(r2dbc-spi、各大驱动 r2dbc-mysql)
● 驱动:
○ 获取连接
○ 发送SQL、执行
○ 封装数据库返回结果
今日任务:
● r2dbc原生API:https://r2dbc.io
● boot整合spring data r2dbc:spring-boot-starter-data-r2dbc
● 三大组件:R2dbcRepository、R2dbcEntityTemplate 、DatabaseClient
● RBAC权限模型导入,基础CRUD练习;SQL文件在附录
● 1-1,1-N 关系处理;
● 扩展:导入接口文档进行测试: 访问 项目/doc.html
<dependency>
<groupId>org.springdoc</groupId>
<artifactId>springdoc-openapi-starter-webflux-ui</artifactId>
<version>2.0.2</version>
</dependency>
<dependency>
<groupId>com.github.xiaoymin</groupId>
<artifactId>knife4j-openapi3-ui</artifactId>
<version>4.0.0</version>
</dependency>
用法:
1、导入驱动: 导入连接池(r2dbc-pool)、导入驱动(r2dbc-mysql )
2、使用驱动提供的API操作
<dependency>
<groupId>io.asyncer</groupId>
<artifactId>r2dbc-mysql</artifactId>
<version>1.0.5</version>
</dependency>
//0、MySQL配置
MySqlConnectionConfiguration configuration = MySqlConnectionConfiguration.builder()
.host("localhost")
.port(3306)
.username("root")
.password("123456")
.database("test")
.build();
//1、获取连接工厂
MySqlConnectionFactory connectionFactory = MySqlConnectionFactory.from(configuration);
//2、获取到连接,发送sql
// JDBC: Statement: 封装sql的
//3、数据发布者
Mono.from(connectionFactory.create())
.flatMapMany(connection ->
connection
.createStatement("select * from t_author where id=?id and name=?name")
.bind("id",1L) //具名参数
.bind("name","张三")
.execute()
).flatMap(result -> {
return result.map(readable -> {
Long id = readable.get("id", Long.class);
String name = readable.get("name", String.class);
return new TAuthor(id, name);
});
})
.subscribe(tAuthor -> System.out.println("tAuthor = " + tAuthor))
;
二、Spring Data R2DBC
提升生产力方式的 响应式数据库操作
1、整合
1.1、导入依赖
<!-- https://mvnrepository.com/artifact/io.asyncer/r2dbc-mysql -->
<dependency>
<groupId>io.asyncer</groupId>
<artifactId>r2dbc-mysql</artifactId>
<version>1.0.5</version>
</dependency>
<!-- 响应式 Spring Data R2dbc-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-r2dbc</artifactId>
</dependency>
1.2、编写配置
spring:
r2dbc:
password: 123456
username: root
url: r2dbc:mysql://localhost:3306/test
name: test
2、声明式接口:R2dbcRepository
2.1、Repository接口
@Repository
public interface AuthorRepositories extends R2dbcRepository<TAuthor,Long> {
//默认继承了一堆CRUD方法; 像mybatis-plus
//QBC: Query By Criteria
//QBE: Query By Example
//成为一个起名工程师 where id In () and name like ?
//仅限单表复杂条件查询
Flux<TAuthor> findAllByIdInAndNameLike(Collection<Long> id, String name);
//多表复杂查询
@Query("select * from t_author") //自定义query注解,指定sql语句
Flux<TAuthor> findHaha();
// 1-1:关联
// 1-N:关联
//场景:
// 1、一个图书有唯一作者; 1-1
// 2、一个作者可以有很多图书: 1-N
}
2.2、自定义Converter
package com.atguigu.r2dbc.config.converter;
import com.atguigu.r2dbc.entity.TAuthor;
import com.atguigu.r2dbc.entity.TBook;
import io.r2dbc.spi.Row;
import org.springframework.core.convert.converter.Converter;
import org.springframework.data.convert.ReadingConverter;
import java.time.Instant;
/**
* @author lfy
* @Description
* @create 2023-12-23 22:04
*
* 告诉Spring Data 怎么封装Book对象
*/
@ReadingConverter //读取数据库数据的时候,把row转成 TBook
public class BookConverter implements Converter<Row, TBook> {
@Override
public TBook convert(Row source) {
if(source == null) return null;
//自定义结果集的封装
TBook tBook = new TBook();
tBook.setId(source.get("id", Long.class));
tBook.setTitle(source.get("title", String.class));
Long author_id = source.get("author_id", Long.class);
tBook.setAuthorId(author_id);
// tBook.setPublishTime(source.get("publish_time", Instant.class));
TAuthor tAuthor = new TAuthor();
tAuthor.setId(author_id);
tAuthor.setName(source.get("name", String.class));
tBook.setAuthor(tAuthor);
return null;
}
}
2.3、配置生效
@EnableR2dbcRepositories //开启 R2dbc 仓库功能;jpa
@Configuration
public class R2DbcConfiguration {
@Bean //替换容器中原来的
@ConditionalOnMissingBean
public R2dbcCustomConversions conversions(){
//把我们的转换器加入进去; 效果新增了我们的 Converter
return R2dbcCustomConversions.of(MySqlDialect.INSTANCE,new BookConverter());
}
}
3、编程式组件
● R2dbcEntityTemplate
● DatabaseClient
三、RBAC-SQL练习
1、1-1
自定义 Converter<Row,Bean> 方式
@Bean
R2dbcCustomConversions r2dbcCustomConversions(){
List<Converter<?, ?>> converters = new ArrayList<>();
converters.add(new BookConverter());
return R2dbcCustomConversions.of(MySqlDialect.INSTANCE, converters);
}
//1-1: 结合自定义 Converter
bookRepostory.hahaBook(1L)
.subscribe(tBook -> System.out.println("tBook = " + tBook));
编程式封装方式: 使用DatabaseClient
//1-1:第二种方式
databaseClient.sql("select b.*,t.name as name from t_book b " +
"LEFT JOIN t_author t on b.author_id = t.id " +
"WHERE b.id = ?")
.bind(0, 1L)
.fetch()
.all()
.map(row-> {
String id = row.get("id").toString();
String title = row.get("title").toString();
String author_id = row.get("author_id").toString();
String name = row.get("name").toString();
TBook tBook = new TBook();
tBook.setId(Long.parseLong(id));
tBook.setTitle(title);
TAuthor tAuthor = new TAuthor();
tAuthor.setName(name);
tAuthor.setId(Long.parseLong(author_id));
tBook.setAuthor(tAuthor);
return tBook;
})
.subscribe(tBook -> System.out.println("tBook = " + tBook));
2、1-N
使用底层API DatabaseClient;
@Test
void oneToN() throws IOException {
// databaseClient.sql("select a.id aid,a.name,b.* from t_author a " +
// "left join t_book b on a.id = b.author_id " +
// "order by a.id")
// .fetch()
// .all(row -> {
//
// })
// 1~6
// 1:false 2:false 3:false 4: true 8:true 5:false 6:false 7:false 8:true 9:false 10:false
// [1,2,3]
// [4,8]
// [5,6,7]
// [8]
// [9,10]
// bufferUntilChanged:
// 如果下一个判定值比起上一个发生了变化就开一个新buffer保存,如果没有变化就保存到原buffer中
// Flux.just(1,2,3,4,8,5,6,7,8,9,10)
// .bufferUntilChanged(integer -> integer%4==0 )
// .subscribe(list-> System.out.println("list = " + list));
; //自带分组
Flux<TAuthor> flux = databaseClient.sql("select a.id aid,a.name,b.* from t_author a " +
"left join t_book b on a.id = b.author_id " +
"order by a.id")
.fetch()
.all()
.bufferUntilChanged(rowMap -> Long.parseLong(rowMap.get("aid").toString()))
.map(list -> {
TAuthor tAuthor = new TAuthor();
Map<String, Object> map = list.get(0);
tAuthor.setId(Long.parseLong(map.get("aid").toString()));
tAuthor.setName(map.get("name").toString());
//查到的所有图书
List<TBook> tBooks = list.stream()
.map(ele -> {
TBook tBook = new TBook();
tBook.setId(Long.parseLong(ele.get("id").toString()));
tBook.setAuthorId(Long.parseLong(ele.get("author_id").toString()));
tBook.setTitle(ele.get("title").toString());
return tBook;
})
.collect(Collectors.toList());
tAuthor.setBooks(tBooks);
return tAuthor;
});//Long 数字缓存 -127 - 127;// 对象比较需要自己写好equals方法
flux.subscribe(tAuthor -> System.out.println("tAuthor = " + tAuthor));
System.in.read();
}
四、最佳实践
最佳实践: 提升生产效率的做法
● 1、Spring Data R2DBC,基础的CRUD用 R2dbcRepository 提供好了
● 2、自定义复杂的SQL(单表): @Query;
● 3、多表查询复杂结果集: DatabaseClient 自定义SQL及结果封装;
○ @Query + 自定义 Converter 实现结果封装
经验:
● 1-1:1-N 关联关系的封装都需要自定义结果集的方式
○ Spring Data R2DBC:
■ 自定义Converter指定结果封装
■ DatabaseClient:贴近底层的操作进行封装; 见下面代码
○ MyBatis: 自定义 ResultMap 标签去来封装
databaseClient.sql("select b.*,t.name as name from t_book b " +
"LEFT JOIN t_author t on b.author_id = t.id " +
"WHERE b.id = ?")
.bind(0, 1L)
.fetch()
.all()
.map(row-> {
String id = row.get("id").toString();
String title = row.get("title").toString();
String author_id = row.get("author_id").toString();
String name = row.get("name").toString();
TBook tBook = new TBook();
tBook.setId(Long.parseLong(id));
tBook.setTitle(title);
TAuthor tAuthor = new TAuthor();
tAuthor.setName(name);
tAuthor.setId(Long.parseLong(author_id));
tBook.setAuthor(tAuthor);
return tBook;
})
.subscribe(tBook -> System.out.println("tBook = " + tBook));
五、附录
RBAC SQL文件
-- 用户表
DROP TABLE IF EXISTS `t_user`;
CREATE TABLE `t_user`(
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`username` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '用户名',
`password` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '密码',
`email` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '邮箱',
`phone` char(11) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '电话',
`create_time` datetime(0) NOT NULL COMMENT '创建时间',
`update_time` datetime(0) NOT NULL COMMENT '更新时间',
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
-- 角色表
DROP TABLE IF EXISTS `t_roles`;
CREATE TABLE `t_roles`(
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '角色名',
`value` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '角色的英文名',
`create_time` datetime(0) NOT NULL,
`update_time` datetime(0) NOT NULL,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
-- 权限表(资源表)
DROP TABLE IF EXISTS `t_perm`;
CREATE TABLE `t_perm`(
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`value` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '权限字段',
`uri` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '资源路径',
`description` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL COMMENT '资源描述',
`create_time` datetime(0) NOT NULL,
`update_time` datetime(0) NOT NULL,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
-- 用户角色关系表
DROP TABLE IF EXISTS `t_user_role`;
CREATE TABLE `t_user_role`(
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`user_id` bigint(20) NOT NULL,
`role_id` bigint(20) NOT NULL,
`create_time` datetime(0) NOT NULL,
`update_time` datetime(0) NOT NULL,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
-- 角色权限关系表
DROP TABLE IF EXISTS `t_role_perm`;
CREATE TABLE `t_role_perm`(
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`role_id` bigint(20) NOT NULL,
`perm_id` bigint(20) NOT NULL,
`create_time` datetime(0) NOT NULL,
`update_time` datetime(0) NOT NULL,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
-- 图书&作者表
CREATE TABLE `t_book`(
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`title` varchar(255) NOT NULL,
`author_id` bigint(20) NOT NULL,
`publish_time` datetime(0) NOT NULL,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
CREATE TABLE `t_author`(
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`name` varchar(255) NOT NULL,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;