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SpringBoot_第七章(读写分离)

news 2025/7/10 6:22:42

这里列举了三种读写分离实现方案,分别是如下三种

1：MybatisPlus（读写分离）

1.1：首先创建三个数据库1主2从

表名是user表

1.2：代码实例

1：导入pom

<!--MybatisPlus的jar 3.0基于jdk8--><dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.5.3.1</version></dependency><!-- mybatisPlus多数据源依赖  实现读写分离--><dependency><groupId>com.baomidou</groupId><artifactId>dynamic-datasource-spring-boot-starter</artifactId><version>3.6.1</version></dependency><!-- mysql的依赖--><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.33</version></dependency><!--直接使用druid的starter 连接池--><dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId><version>1.2.16</version></dependency>

2：配置spring的主从

server:port: 8082spring:datasource:dynamic:primary: master #设置默认的数据源或者数据源组,默认值即为masterstrict: false #严格匹配数据源,默认false. true未匹配到指定数据源时抛异常,false使用默认数据源datasource:master:url: jdbc:mysql://localhost:3306/W1?useUnicode=true&characterEncoding=utf-8&useSSL=falseusername: rootpassword: 123456driver-class-name: com.mysql.cj.jdbc.Drivertype: com.alibaba.druid.pool.DruidDataSource #配置德鲁伊数据源druid:initial-size: 10 #连接池初始化大小min-idle: 10 #最小空闲连接数max-active: 20 #最大连接数slave_1:url: jdbc:mysql://localhost:3306/W1R1?useUnicode=true&characterEncoding=utf-8&useSSL=falseusername: rootpassword: 123456driver-class-name: com.mysql.cj.jdbc.Drivertype: com.alibaba.druid.pool.DruidDataSource #配置德鲁伊数据源druid:initial-size: 10 #连接池初始化大小min-idle: 10 #最小空闲连接数max-active: 20 #最大连接数slave_2:url: jdbc:mysql://localhost:3306/W1R2?useUnicode=true&characterEncoding=utf-8&useSSL=falseusername: rootpassword: 123456driver-class-name: com.mysql.cj.jdbc.Drivertype: com.alibaba.druid.pool.DruidDataSource #配置德鲁伊数据源druid:initial-size: 10 #连接池初始化大小min-idle: 10 #最小空闲连接数max-active: 20 #最大连接数#......省略#以上会配置一个默认库master，一个组slave下有两个子库slave_1,slave_2

3：代码实例 @DS("slave") 注解用来切换数据源

/**
* @description 针对表【User】的数据库操作Service实现
* @createDate 2023-11-01 17:17:57
*/
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService{@ResourceUserMapper userMapper;//多个从库 负载均衡轮训查询 也可以注解到类上//@DS("slave")@DS("slave")public User selectRW_S(Integer id) {return userMapper.selectById(id);}//主库查询数据//@DS("master")@DS("master")public User selectRW_M(Integer id) {return userMapper.selectById(id);}//无注解，不指定数据, 默认查询主库@Overridepublic User selectRW(Integer id) {return userMapper.selectById(id);}
}

controller代码根据请求不同访问不同的数据源

@RestController
public class UserControllerRW {@ResourceUserServiceImpl userService;//查询主库 @DS("master")@GetMapping(value = "selectRW1")public User selectRW_M(@RequestParam(name = "id",required = true) Integer id){User user = userService.selectRW_M(id);System.out.println(user);return user;}//查询从库 @DS("slave") 轮训查询@GetMapping(value = "selectRW2")public User selectRW_S(@RequestParam(name = "id",required = true) Integer id){User user = userService.selectRW_S(id);System.out.println(user);return user;}//无注解，不指定数据, 默认查询主库@GetMapping(value = "selectRW3")public User selectRW(@RequestParam(name = "id",required = true) Integer id){User user = userService.selectRW(id);System.out.println(user);return user;}
}

查询结果截图