第一种方式： AbstractRoutingDataSource
1.1. 手动切换数据源
application.properties
-
# Order
-
# 如果用Druid作为数据源，应该用url属性，而不是jdbc-url
-
spring.datasource.order.jdbc-url=
jdbc:
mysql:/
/localhost:3306/order?useUnicode=
true&characterEncoding=utf8&allowMultiQueries=
true&useSSL=
false
-
spring.datasource.order.username=root
-
spring.datasource.order.password=
123456
-
spring.datasource.order.driver-
class-name=com.mysql.cj.jdbc.Driver
-
# Stock
-
spring.datasource.stock.jdbc-url=
jdbc:
mysql:/
/localhost:3306/stock?useUnicode=
true&characterEncoding=utf8&allowMultiQueries=
true&useSSL=
false
-
spring.datasource.stock.username=root
-
spring.datasource.stock.password=
123456
-
spring.datasource.stock.driver-
class-name=com.mysql.cj.jdbc.Driver
-
# Account
-
spring.datasource.account.jdbc-url=
jdbc:
mysql:/
/localhost:3306/account?useUnicode=
true&characterEncoding=utf8&allowMultiQueries=
true&useSSL=
false
-
spring.datasource.account.username=root
-
spring.datasource.account.password=
123456
-
spring.datasource.account.driver-
class-name=com.mysql.cj.jdbc.Driver
配置数据源
DataSourceConfig.java
-
package com.cjs.example.config;
-
-
import com.alibaba.druid.pool.DruidDataSource;
-
import com.baomidou.mybatisplus.extension.spring.MybatisSqlSessionFactoryBean;
-
import com.zaxxer.hikari.HikariDataSource;
-
import org.mybatis.spring.SqlSessionFactoryBean;
-
import org.springframework.beans.factory.
annotation.Qualifier;
-
import org.springframework.boot.context.properties.ConfigurationProperties;
-
import org.springframework.boot.jdbc.DataSourceBuilder;
-
import org.springframework.context.
annotation.Bean;
-
import org.springframework.context.
annotation.Configuration;
-
import org.springframework.context.
annotation.Primary;
-
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
-
-
import javax.sql.DataSource;
-
import java.util.HashMap;
-
import java.util.Map;
-
-
@Configuration
-
public
class
DataSourceConfig {
-
-
@Bean("orderDataSource")
-
@ConfigurationProperties(prefix = "spring.datasource.order")
-
public DataSource orderDataSource() {
-
// return new HikariDataSource();
-
// return new DruidDataSource();
-
return DataSourceBuilder.create().build();
-
}
-
-
@Bean("accountDataSource")
-
@ConfigurationProperties(prefix = "spring.datasource.account")
-
public DataSource accountDataSource() {
-
// return new HikariDataSource();
-
// return new DruidDataSource();
-
return DataSourceBuilder.create().build();
-
}
-
-
@Bean("stockDataSource")
-
@ConfigurationProperties(prefix = "spring.datasource.stock")
-
public DataSource stockDataSource() {
-
// return new HikariDataSource();
-
// return new DruidDataSource();
-
return DataSourceBuilder.create().build();
-
}
-
-
@Primary
-
@Bean("dynamicDataSource")
-
public DataSource dynamicDataSource(
@Qualifier("orderDataSource") DataSource orderDataSource,
-
@Qualifier("accountDataSource") DataSource accountDataSource,
-
@Qualifier("stockDataSource") DataSource stockDataSource) {
-
-
Map<Object, Object> dataSourceMap = new HashMap<>(
3);
-
dataSourceMap.put(DataSourceKey.ORDER.name(), orderDataSource);
-
dataSourceMap.put(DataSourceKey.STOCK.name(), stockDataSource);
-
dataSourceMap.put(DataSourceKey.ACCOUNT.name(), accountDataSource);
-
-
DynamicRoutingDataSource dynamicRoutingDataSource = new DynamicRoutingDataSource();
-
dynamicRoutingDataSource.setDefaultTargetDataSource(orderDataSource);
-
dynamicRoutingDataSource.setTargetDataSources(dataSourceMap);
-
-
return dynamicRoutingDataSource;
-
}
-
-
/* https://baomidou.com/pages/3b5af0/ */
-
@Bean
-
public MybatisSqlSessionFactoryBean sqlSessionFactoryBean(
@Qualifier("dynamicDataSource") DataSource dataSource) {
-
MybatisSqlSessionFactoryBean sqlSessionFactoryBean = new MybatisSqlSessionFactoryBean();
-
sqlSessionFactoryBean.setDataSource(dataSource);
-
// sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mappers/*.xml"));
-
return sqlSessionFactoryBean;
-
}
-
}
由于是MyBatsi-Plus，所以配的是MybatisSqlSessionFactoryBean，如果是MyBatis，则应该是SqlSessionFactoryBean
DataSourceKey.java
-
package com.cjs.example.config;
-
-
public
enum
DataSourceKey {
-
/**
-
* Order data source key.
-
*/
-
ORDER,
-
/**
-
* Stock data source key.
-
*/
-
STOCK,
-
/**
-
* Account data source key.
-
*/
-
ACCOUNT
-
}
DynamicDataSourceContextHolder.java
-
package com.
cjs.
example.
config;
-
-
public
class
DynamicDataSourceContextHolder {
-
-
private
static final
ThreadLocal<
String>
CONTEXT_HOLDER =
ThreadLocal.
withInitial(
DataSourceKey.
ORDER::name);
-
-
public
static
void
setDataSourceKey(
DataSourceKey key) {
-
CONTEXT_HOLDER.
set(key.
name());
-
}
-
-
public
static
String
getDataSourceKey(
) {
-
return
CONTEXT_HOLDER.
get();
-
}
-
-
public
static
void
clearDataSourceKey(
) {
-
CONTEXT_HOLDER.
remove();
-
}
-
-
}
DynamicRoutingDataSource.java
-
package com.cjs.example.config;
-
-
import lombok.extern.slf4j.
Slf4j;
-
import org.springframework.jdbc.datasource.lookup.
AbstractRoutingDataSource;
-
-
@Slf4j
-
public
class DynamicRoutingDataSource extends AbstractRoutingDataSource {
-
@Override
-
protected
Object determineCurrentLookupKey() {
-
log.info(
"当前数据源 [{}]",
DynamicDataSourceContextHolder.getDataSourceKey());
-
return
DynamicDataSourceContextHolder.getDataSourceKey();
-
}
-
}
好了，配置完以后，在操作数据库之前，先设置用哪个数据源即可，就像下面这样：
DynamicDataSourceContextHolder.setDataSourceKey(DataSourceKey.ACCOUNT);举个例子：
-
package com.cjs.example;
-
-
import com.cjs.example.account.entity.Account;
-
import com.cjs.example.account.service.IAccountService;
-
import com.cjs.example.config.DataSourceKey;
-
import com.cjs.example.config.DynamicDataSourceContextHolder;
-
import com.cjs.example.order.entity.Order;
-
import com.cjs.example.order.service.IOrderService;
-
import com.cjs.example.stock.entity.Stock;
-
import com.cjs.example.stock.service.IStockService;
-
import org.junit.jupiter.api.Test;
-
import org.springframework.beans.factory.annotation.Autowired;
-
import org.springframework.boot.test.context.SpringBootTest;
-
-
import java.math.BigDecimal;
-
-
@SpringBootTest
-
public
class
Demo1122ApplicationTests {
-
-
@Autowired
-
private IOrderService orderService;
-
@Autowired
-
private IAccountService accountService;
-
@Autowired
-
private IStockService stockService;
-
-
@Test
-
public
void
doBusiness
() {
-
DynamicDataSourceContextHolder.setDataSourceKey(DataSourceKey.ORDER);
-
Order
order
=
new
Order();
-
order.setOrderNo(
"123");
-
order.setUserId(
"1");
-
order.setCommodityCode(
"abc");
-
order.setCount(
1);
-
order.setAmount(
new
BigDecimal(
"9.9"));
-
orderService.save(order);
-
-
DynamicDataSourceContextHolder.setDataSourceKey(DataSourceKey.STOCK);
-
Stock
stock
=
new
Stock();
-
stock.setId(
1);
-
stock.setCommodityCode(
"abc");
-
stock.setName(
"huawei");
-
stock.setCount(
1);
-
stockService.updateById(stock);
-
-
DynamicDataSourceContextHolder.setDataSourceKey(DataSourceKey.ACCOUNT);
-
Account
account
=
new
Account();
-
account.setId(
1);
-
account.setUserId(
"1");
-
account.setAmount(
new
BigDecimal(
100));
-
accountService.updateById(account);
-
}
-
-
}
这样写看起来确实有些麻烦，通常可能不会像这样在一个方法里操作多个数据库，就比如说假设这是一个管理后台，为了图省事把所有业务都写在这一个项目里，这个时候就需要配置多个数据源，各个数据库的业务互相没有关联，只是写在同一个项目中而已，这样的话如果每次都手动设置数据源太麻烦，可以定义一个AOP切面来自动切换数据源。
1.2. 自动切换数据源
給刚才的代码升个级，利用AOP来拦截目标方法自动切换数据源
1、添加@EnableAspectJAutoProxy注解
-
package com.cjs.example;
-
-
import org.mybatis.spring.
annotation.MapperScan;
-
import org.springframework.boot.SpringApplication;
-
import org.springframework.boot.autoconfigure.SpringBootApplication;
-
import org.springframework.context.
annotation.EnableAspectJAutoProxy;
-
-
@EnableAspectJAutoProxy
-
@MapperScan("com.cjs.example.*.mapper")
-
@SpringBootApplication
-
public
class
Demo1122Application {
-
public static void main(String[] args) {
-
SpringApplication.run(Demo1122Application.
class, args);
-
}
-
}
2、定义切面、切点、通知
-
package com.cjs.example.aop;
-
-
import com.cjs.example.config.DataSourceKey;
-
import com.cjs.example.config.DynamicDataSourceContextHolder;
-
import org.aspectj.lang.ProceedingJoinPoint;
-
import org.aspectj.lang.annotation.Around;
-
import org.aspectj.lang.annotation.Aspect;
-
import org.aspectj.lang.annotation.Pointcut;
-
import org.springframework.stereotype.Component;
-
-
@Aspect
-
@Component
-
public
class
DataSourceAdvice {
-
-
// @Pointcut("within(com.cjs.example.order..*)")
-
@Pointcut("execution(* com.cjs.example.order..*.*(..))")
-
public
void
orderPointcut
() {}
-
-
// @Pointcut("within(com.cjs.example.account..*)")
-
@Pointcut("execution(* com.cjs.example.account..*.*(..))")
-
public
void
accountPointcut
() {}
-
-
// @Pointcut("within(com.cjs.example.stock..*)")
-
@Pointcut("execution(* com.cjs.example.stock..*.*(..))")
-
public
void
stockPointcut
() {}
-
-
-
@Around("orderPointcut()")
-
public Object
order
(ProceedingJoinPoint pjp)
throws Throwable {
-
DynamicDataSourceContextHolder.setDataSourceKey(DataSourceKey.ORDER);
-
Object
retVal
= pjp.proceed();
-
DynamicDataSourceContextHolder.clearDataSourceKey();
-
return retVal;
-
}
-
@Around("accountPointcut()")
-
public Object
account
(ProceedingJoinPoint pjp)
throws Throwable {
-
DynamicDataSourceContextHolder.setDataSourceKey(DataSourceKey.ACCOUNT);
-
Object
retVal
= pjp.proceed();
-
DynamicDataSourceContextHolder.clearDataSourceKey();
-
return retVal;
-
}
-
@Around("stockPointcut()")
-
public Object
stock
(ProceedingJoinPoint pjp)
throws Throwable {
-
DynamicDataSourceContextHolder.setDataSourceKey(DataSourceKey.STOCK);
-
Object
retVal
= pjp.proceed();
-
DynamicDataSourceContextHolder.clearDataSourceKey();
-
return retVal;
-
}
-
}
现在就不用每次调用service方法前手动设置数据源了
工程结构
第二种方式：dynamic-datasource-spring-boot-starter
功能很强大，支持 数据源分组 ，适用于多种场景 纯粹多库 读写分离 一主多从 混合模式
1、引入dynamic-datasource-spring-boot-starter
-
<dependency>
-
<groupId>com.baomidou
</groupId>
-
<artifactId>dynamic-datasource-spring-boot-starter
</artifactId>
-
<version>3.5.2
</version>
-
</dependency>
2、配置数据源
-
spring:
-
datasource:
-
dynamic:
-
primary: master
#设置默认的数据源或者数据源组,默认值即为master
-
strict:
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:/
/xx.xx.xx.xx:3306/dynamic
-
username: root
-
password:
123456
-
driver-
class-name: com.mysql.jdbc.Driver # 3.2.0开始支持SPI可省略此配置
-
slave_1:
-
url:
jdbc:
mysql:/
/xx.xx.xx.xx:3307/dynamic
-
username: root
-
password:
123456
-
driver-
class-name: com.mysql.jdbc.Driver
-
slave_2:
-
url: ENC(xxxxx)
# 内置加密,使用请查看详细文档
-
username: ENC(xxxxx)
-
password: ENC(xxxxx)
-
driver-
class-name: com.mysql.jdbc.Driver
-
#......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
主从配置，读写分离
-
# 多主多从 纯粹多库（记得设置
primary） 混合配置
-
spring: spring: spring:
-
datasource: datasource: datasource:
-
dynamic:
dynamic:
dynamic:
-
datasource: datasource: datasource:
-
master_1: mysql: master:
-
master_2: oracle: slave_1:
-
slave_1: sqlserver: slave_2:
-
slave_2: postgresql: oracle_1:
-
slave_3: h2: oracle_2:
改造一下前面的例子
-
spring.datasource.dynamic.primary=order
-
# Order
-
spring.datasource.dynamic.datasource.order.url=
jdbc:
mysql:/
/localhost:3306/order?useUnicode=
true&characterEncoding=utf8&allowMultiQueries=
true&useSSL=
false
-
spring.datasource.dynamic.datasource.order.username=root
-
spring.datasource.dynamic.datasource.order.password=
123456
-
spring.datasource.dynamic.datasource.order.driver-
class-name=com.mysql.cj.jdbc.Driver
-
# Stock
-
spring.datasource.dynamic.datasource.stock.url=
jdbc:
mysql:/
/localhost:3306/stock?useUnicode=
true&characterEncoding=utf8&allowMultiQueries=
true&useSSL=
false
-
spring.datasource.dynamic.datasource.stock.username=root
-
spring.datasource.dynamic.datasource.stock.password=
123456
-
spring.datasource.dynamic.datasource.stock.driver-
class-name=com.mysql.cj.jdbc.Driver
-
# Account
-
spring.datasource.dynamic.datasource.account.url=
jdbc:
mysql:/
/localhost:3306/account?useUnicode=
true&characterEncoding=utf8&allowMultiQueries=
true&useSSL=
false
-
spring.datasource.dynamic.datasource.account.username=root
-
spring.datasource.dynamic.datasource.account.password=
123456
-
spring.datasource.dynamic.datasource.account.driver-
class-name=com.mysql.cj.jdbc.Driver
3、使用 @DS 切换数据源
@DS 可以注解在方法上或类上，同时存在就近原则 方法上注解 优先于 类上注解
| 注解 | 结果 |
| 没有@DS | 默认数据源 |
| @DS("dsName") | dsName可以为组名也可以为具体某个库的名称 |
-
package com.cjs.example.order.service.impl;
-
-
import com.baomidou.dynamic.datasource.annotation.
DS;
-
import com.cjs.example.order.entity.
Order;
-
import com.cjs.example.order.mapper.
OrderMapper;
-
import com.cjs.example.order.service.
IOrderService;
-
import com.baomidou.mybatisplus.extension.service.impl.
ServiceImpl;
-
import org.springframework.stereotype.
Service;
-
-
@DS(
"order")
-
@Service
-
public
class OrderServiceImpl extends ServiceImpl<OrderMapper, Order> implements IOrderService {
-
-
}
-
package com.cjs.example.stock.service.impl;
-
-
import com.baomidou.dynamic.datasource.annotation.
DS;
-
import com.cjs.example.stock.entity.
Stock;
-
import com.cjs.example.stock.mapper.
StockMapper;
-
import com.cjs.example.stock.service.
IStockService;
-
import com.baomidou.mybatisplus.extension.service.impl.
ServiceImpl;
-
import org.springframework.stereotype.
Service;
-
-
@DS(
"stock")
-
@Service
-
public
class StockServiceImpl extends ServiceImpl<StockMapper, Stock> implements IStockService {
-
-
}
-
package com.cjs.example.account.service.impl;
-
-
import com.baomidou.dynamic.datasource.annotation.
DS;
-
import com.cjs.example.account.entity.
Account;
-
import com.cjs.example.account.mapper.
AccountMapper;
-
import com.cjs.example.account.service.
IAccountService;
-
import com.baomidou.mybatisplus.extension.service.impl.
ServiceImpl;
-
import org.springframework.stereotype.
Service;
-
-
@DS(
"account")
-
@Service
-
public
class AccountServiceImpl extends ServiceImpl<AccountMapper, Account> implements IAccountService {
-
-
}
转载：https://blog.csdn.net/wufaqidong1/article/details/127990507
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