1 概述
之前笔者写过两篇文章:
这里将两者结合起来,实现读写分离+分库分表的功能。关于环境的配置本文将进行简化叙述,详细可以参考前两篇文章。
2 环境
-
MySQL 8.0.25
(Docker
) MyBatis Plus 3.4.3.1
MyBatis Plus Generator 3.5.0
Druid 1.2.6
ShardingSphere 4.1.1
-
Yitter 1.0.6
(一个雪花id
生成器)
3 数据库环境准备
由于环境准备不是本文的重点,一主一从的主从复制环境可以参考此处搭建。
准备好环境,本地启动两个MySQL
,主节点环境:
- 名字:
master
- 端口:
3306
- 数据库:两个库(
test0
、test1
) - 数据表:六个表,每个库三个(
test0.user0
、test0.user1
、test0.user2
、test1.user0
、test1.user1
、test1.user2
)
从节点环境:
- 名字:
slave
- 端口:
3307
- 数据库:两个库(
test0
、test1
) - 数据表:六个表,每个库三个(
test0.user0
、test0.user1
、test0.user2
、test1.user0
、test1.user1
、test1.user2
)
主库配置文件:
[mysqld]
server-id=1
binlog-do-db=test0
binlog-do-db=test1
从库配置文件:
[mysqld]
server-id=2
replicate-do-db=test0
replicate-do-db=test1
完整的数据库脚本和MySQL
配置文件放在文末的源码链接中。
4 新建项目
新建项目并引入如下依赖:
Druid
MyBatis Plus starter
MyBaits Plus Generator
Velocity core
ShardingSphere
Yitter
Maven
如下:
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.4.3.1</version>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-generator</artifactId>
<version>3.5.0</version>
</dependency>
<dependency>
<groupId>org.apache.velocity</groupId>
<artifactId>velocity-engine-core</artifactId>
<version>2.3</version>
</dependency>
<dependency>
<groupId>org.realityforge.org.jetbrains.annotations</groupId>
<artifactId>org.jetbrains.annotations</artifactId>
<version>1.7.0</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.2.6</version>
</dependency>
<dependency>
<groupId>org.apache.shardingsphere</groupId>
<artifactId>sharding-jdbc-spring-boot-starter</artifactId>
<version>4.1.1</version>
</dependency>
<dependency>
<groupId>com.github.yitter</groupId>
<artifactId>yitter-idgenerator</artifactId>
<version>1.0.6</version>
</dependency>
Gradle
如下:
implementation 'com.baomidou:mybatis-plus-boot-starter:3.4.3.1'
implementation 'org.apache.velocity:velocity-engine-core:2.3'
implementation 'org.realityforge.org.jetbrains.annotations:org.jetbrains.annotations:1.7.0'
implementation 'com.alibaba:druid:1.2.6'
implementation 'org.apache.shardingsphere:sharding-jdbc-spring-boot-starter:4.1.1'
implementation 'com.github.yitter:yitter-idgenerator:1.0.6'
5 配置文件
spring:
shardingsphere:
datasource:
names: master-test0,master-test1,slave-test0,slave-test1 # 数据源节点名字
# master-test0表示主节点的test0库,master-test1表示主节点的test1库
# slave-test0表示从节点的test0库,slave-test1表示从节点的test1库
master-test0:
type: com.alibaba.druid.pool.DruidDataSource # 连接池
url: jdbc:mysql://127.0.0.1:3306/test0 # 主节点的test0库
username: root
password: 123456
master-test1:
type: com.alibaba.druid.pool.DruidDataSource
url: jdbc:mysql://127.0.0.1:3306/test1 # 主节点的test1库
username: root
password: 123456
slave-test0:
type: com.alibaba.druid.pool.DruidDataSource
url: jdbc:mysql://127.0.0.1:3307/test0 # 从节点的test0库,端口3307
username: root
password: 123456
slave-test1:
type: com.alibaba.druid.pool.DruidDataSource
url: jdbc:mysql://127.0.0.1:3307/test1 # 从节点的test1库,端口3307
username: root
password: 123456
sharding:
default-database-strategy:
inline:
sharding-column: age # 按照哪一列分库
algorithm-expression: master-test$->{age % 2} # 分库规则为对年龄取模
tables:
user:
actual-data-nodes: master-test$->{0..1}.user$->{0..2} # 分表的节点,格式为 [数据源.表名]
table-strategy:
inline:
sharding-column: id # 按照哪一列分表
algorithm-expression: user$->{id%3} # 分表规则,对id取模
master-slave-rules: # 读写分离的规则
master-test0: # 哪一个主节点
master-datasource-name: master-test0 # 指定主节点名字
slave-data-source-names: slave-test0 # 指定从节点名字
master-test1:
master-datasource-name: master-test1
slave-data-source-names: slave-test1
props:
sql:
show:
true # 打印SQL
6 准备测试代码
使用MyBatis Plus Generator
生成器类生成代码:
import com.baomidou.mybatisplus.generator.AutoGenerator;
import com.baomidou.mybatisplus.generator.config.*;
public class MyBatisPlusGenerator {
public static void main(String[] args) {
DataSourceConfig dataSourceConfig = new DataSourceConfig.Builder("jdbc:mysql://localhost:3306/test0", "root", "123456").build();
String projectPath = System.getProperty("user.dir");
StrategyConfig strategyConfig = new StrategyConfig.Builder().addInclude("user").build();
GlobalConfig globalConfig = new GlobalConfig.Builder().outputDir(projectPath + "/src/main/java").openDir(false).build();
PackageConfig packageConfig = new PackageConfig.Builder().moduleName("user").parent("com.example.demo").serviceImpl("service").build();
new AutoGenerator(dataSourceConfig).global(globalConfig).packageInfo(packageConfig).strategy(strategyConfig).execute();
}
}
实体类加上@Builder
,同时设置id
类型为IdType.ASSIGN_ID
:
@Builder
public class User implements Serializable {
@TableId(type = IdType.ASSIGN_ID)
private Long id;
//...
}
修改Controller
类:
@RestController
@RequestMapping("/user")
@RequiredArgsConstructor(onConstructor = @__(@Autowired))
public class UserController {
private final Random random = new Random();
private final UserServiceImpl service;
@GetMapping("/select")
public List<User> select(){
return service.list();
}
@GetMapping("/insert")
public boolean insert(){
return service.save(User.builder().age(random.nextInt(80)+20).name("test name").email("test@test.com").build());
}
}
同时新增一个雪花id
生成器类(具体配置方法可以参考MyBatis Plus
官方文档):
import com.baomidou.mybatisplus.core.incrementer.IdentifierGenerator;
import com.github.yitter.contract.IdGeneratorOptions;
import com.github.yitter.idgen.YitIdHelper;
import org.springframework.stereotype.Component;
import javax.annotation.PostConstruct;
@Component
public class IdGenerator implements IdentifierGenerator {
final IdGeneratorOptions options = new IdGeneratorOptions((short) 1);
@PostConstruct
public void init() {
YitIdHelper.setIdGenerator(options);
}
@Override
public Long nextId(Object entity) {
return YitIdHelper.nextId();
}
}
7 测试
刷新几次插入页面:
http://localhost:8080/user/insert
从输出可以看到插入都是在主节点中进行的:
而查询的时候:
http://localhost:8080/user/select
输出如下:
是在从节点查询的。
8 参考代码
Java
版:
Kotlin
版: