SpringBoot3响应式编程全套-R2DBC

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

在这里插入图片描述

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: 123456username: rooturl: r2dbc:mysql://localhost:3306/testname: 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> {@Overridepublic 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@ConditionalOnMissingBeanpublic R2dbcCustomConversions conversions(){//把我们的转换器加入进去； 效果新增了我们的 Converterreturn 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

    @BeanR2dbcCustomConversions 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；

    @Testvoid 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;