ShardingJDBC实现MySQL8集群读写分离

原标题：Sharding-JDBC实现MySQL8集群读写分离

这是一个基于SpringBoot整合Sharding-JDBC实现读写分离的极简教程，笔www.yii666.com者使用到的技术及版本如下：

SpringBoot 2.5.2

MyBatis-Plus 3.4.3

Sharding-JDBC 4.1.1

MySQL8集群（看笔者前一篇文章有部署教程）


<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0modelVersion>
<parent>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-parentartifactId>
<version>2.5.2version>
<relativePath/>
parent>
<文章来源地址48491.html;groupId>xyz.hcworldgroupId>
<artifactId>sharding-jdbc-demoartifactId>
<version>0.0.1-SNAPSHOTversion>
<name>sharding-jdbc-demoname>
<description>多数据源切换实例description>
<properties>
<java.version>1.8java.version>
properties>
<dependencies>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
dependency>

<dependency>
<groupId>com.baomidougroupId>
<artifactId>mybatis-plus-boot-starterartifactId>
<version>3.4.3version>
dependency>

<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<scope>runtimescope>
dependency>

<dependency>
<groupId>org.apache.shardingspheregroupId>
<artifactId>sharding-jdbc-spring-boot-starterartifactId>
<version>4.1.1version>
dependency>
<dependency>
<groupId>org.projectlombokgroupId>
<artifactId>lombokartifactId>
<optional>trueoptional>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-testartifactId>
<scope>testscope>
dependency>
dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-maven-pluginartifactId>
<configuration>
<excludes>
<exclude>
<groupId>org.projectlombokgroupId>
<artifactId>lombokartifactId>
exclude>
excludes>
configuration>
plugin>
plugins>
build>
project>


四.配置文件（基于YAML）及SQL建表语句

spring:
main:
allow-bean-definition-overriding: true
#显示sql
shardingsphere:
props:
sql:
show: true
masterslave:
#配置主从名称
name: ms
#置主库master,负责数据的写入
master-data-source-name: ds1
#配置从库slave节点
slave-data-source-names: ds2,ds3
#配置slave节点的负载均衡均衡策略,采用轮询机制，有两种算法：round_robin(轮询)和random(随机)
load-balance-algorithm-type: round_robin
sharding:
#配置默认数据源ds1 默认数据源,主要用于写
default-data-source-name: ds1
# 配置数据源
datasource:
names: ds1,ds2,ds3
#master-ds1数据库连接信息
ds1:
type: com.zaxxer.hikari.HikariDataSource
driver-class-name: com.mysql.cj.jdbc.Driver
jdbc-url: jdbc:mysql://192.168.2.142:3307/sharding-jdbc-db?useUnicode=true&useSSL=false&serverTimezOne=Asia/Shanghai
username: root
password: 123456
maxPoolSize: 100
minPoolSize: 5
#slave-ds2数据库连接信息
ds2:
type: com.zaxxer.hikari.HikariDataSource
driver-class-name: com.mysql.cj.jdbc.Driver
jdbc-url: jdbc:mysql://192.168.2.142:3308/sharding-jdbc-db?useUnicode=true&useSSL=false&serverTimezOne=Asia/Shanghai
username: root
password: 123456
maxPoolSize: 100
minPoolSize: 5
#slave-ds3数据库连接信息
ds3:
type: com.zaxxer.hikari.HikariDataSource
driver-class-name: com.mysql.cj.jdbc.Driver
jdbc-url: jdbc:mysql://192.168.2.142:3309/sharding-jdbc-db?useUnicode=true&useSSL=false&serverTimezOne=Asia/Shanghai
username: root
password: 123456
maxPoolSize: 100
minPoolSize: 5
#mybatis-plus配置
mybatis-plus:
type-aliases-package: xyz.hcworld.demo.model
mapper-locations: classpath*:/mapper/**Mapper.xml


CREATE TABLE `t_user` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`nickname` varchar(100) DEFAULT NULL,
`password` varchar(100) DEFAULT NULL,
`sex` int(11) DEFAULT NULL,
`birthday` varchar(50) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8mb4;


五.Mapper.xml文件及Mapper接口



<mapper namespace="xyz.hcworld.demo.mapper.UserMapper">
<update id="addUser">
INSERT INTO t_user(nickname,PASSWORD,sex,birthday) VALUES(#{nickname},#{password},#{sex},#{birthday})
update>
<select id="findUsers" resultType="xyz.hcworld.demo.model.User">
SELECT
id,
nickname,
PASSWORD,
sex,
birthday
FROM t_user;
select>
mapper>


package xyz.hcworld.demo.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.springframework.stereotype.Component;
import xyz.hcworld.demo.model.User;
import java.util.List;
/**
* @ClassName: UserMapper
* @Author: 张红尘
* @Date: 2021-07-20
* @Version： 1.0
*/
@Component
public interface UserMapper extends BaseMapper<User> {
void addUser(User user);
List<User> findUsers();
}


六 .Controller及Mocel文件

package xyz.hcworld.demo.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import xyz.hcworld.demo.mapper.UserMapper;
import xyz.hcworld.demo.model.User;
import java.security.SecureRandom;
import java.util.List;
/**
* @ClassName: UserController
* @Author: 张红尘
* @Date: 2021-07-20
* @Version： 1.0
*/
@RestController
@RequestMapping("/api/user")
public class UserController {
@Autowired
private UserMapper userMapper;
@PostMapping("/save")
public String addUser() {
User user = new User();
user.setNickname("zhangsan" + new SecureRandom().nextInt());
文章来源站点https://www.yii666.com/ user.setPassword("123456");
user.setSex(1);
user.setBirthday("1997-12-03");
userMapper.addUser(user);
return user.toString();
文章来源地址48491.html }
@GetMapping("/findUsers")
public List<User> findUsers() {
return userMapper.findUsers();
}
}


package xyz.hcworld.demo.model;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;
import lombok.EqualsAndHashCode;
/**
* @www.yii666.comClassName: User
* @Author: 张红尘
* @Date: 2021-07-20
* @Version： 1.0
*/
@Data
@TableName("t_user")
public class User {
private static final long serialVersionUID = 1L;
@TableId(value = "id", type = IdType.AUTO)
private Integer id;
private String nickname;
private String password;
private Integer sex;
private String birthday;
}


七.结果

从结果可以看出，写入操作全部通过ds1数据库（master）数据库完成，而读操作因为设置了轮询的缘故，由ds2（slaver）、ds3（slaver2）数据库完成。这样就实现了基于一主二从的数据库集群的读写分离操作。

网上Sharding-JDBC的教程多为4.0.0.RC1版本，笔者使用的是最新的4.1.1所以
在该部分数据库地址在4.1.1为jdbc-url在4.0.0.RC1上需要改为url否则会启动失败

jdbc-url: jdbc:mysql://XXXX/XXXX


且网上教程多为properties文件，笔者将其转变为YAML文件更加能直观感受

GitHub:https://github.com/z875479694h/sharding-jdbc-demo

公众号：青山有录
Github：https://github.com/z875479694h
博客：https://www.hcworld.xyz

来源于：Sharding-JDBC实现MySQL8集群读写分离