在Spring boot 中使用@master 设置主从数据库

基础配置

application.yml

spring:
　　datasource:
　　　　master:
　　　　　　url: jdbc:mysql://localhost:3306/master_db
　　　　　　username: root
　　　　　　password: 123456
　　　　　　driver-class-name: com.mysql.cj.jdbc.Driver
　　　　slave:
　　　　　　url: jdbc:mysql://localhost:3306/slave_db
　　　　　　username: root
　　　　　　password: 123456
　　　　　　driver-class-name: com.mysql.cj.jdbc.Driver
mybatis:
　　mapper-locations: classpath:mapper/*.xml

DataSourceConfig

package com.example.multids.config;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.jdbc.datasource.lookup.AbstractRoutingDataSource;import javax.sql.DataSource;
import java.util.HashMap;
import java.util.Map;@Configuration
public class DataSourceConfig {// 主数据源配置（前缀对应application.yml中的spring.datasource.master）
    @Bean@ConfigurationProperties(prefix = "spring.datasource.master")public DataSource masterDataSource() {return DataSourceBuilder.create().build();}// 从数据源配置
    @Bean@ConfigurationProperties(prefix = "spring.datasource.slave")public DataSource slaveDataSource() {return DataSourceBuilder.create().build();}// 动态数据源路由
    @Beanpublic DataSource routingDataSource(DataSource masterDataSource, DataSource slaveDataSource) {AbstractRoutingDataSource routingDataSource = new AbstractRoutingDataSource() {@Overrideprotected Object determineCurrentLookupKey() {return DataSourceContextHolder.getDataSourceType();}};Map<Object, Object> targetDataSources = new HashMap<>();targetDataSources.put("master", masterDataSource);targetDataSources.put("slave", slaveDataSource);routingDataSource.setDefaultTargetDataSource(masterDataSource);routingDataSource.setTargetDataSources(targetDataSources);return routingDataSource;}
}

DataSourceContextHolder

package com.example.multids.config;public class DataSourceContextHolder {private static final ThreadLocal<String> contextHolder = new ThreadLocal<>();// 设置当前线程数据源类型public static void setDataSourceType(String dsType) {contextHolder.set(dsType);}// 获取当前线程数据源类型public static String getDataSourceType() {return contextHolder.get();}// 清除数据源类型public static void clearDataSourceType() {contextHolder.remove();}
}

Master

package com.example.multids.annotation;import java.lang.annotation.*;@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface Master {// 标记使用主数据源
}

DataSourceAspect

package com.example.multids.aspect;import com.example.multids.annotation.Master;
import com.example.multids.config.DataSourceContextHolder;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;@Aspect
@Component
@Order(-1) // 保证在事务注解前执行
public class DataSourceAspect {@Around("@annotation(master)")public Object around(ProceedingJoinPoint point, Master master) throws Throwable {try {DataSourceContextHolder.setDataSourceType("master");return point.proceed();} finally {DataSourceContextHolder.clearDataSourceType();}}
}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-aop</artifactId></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId></dependency></dependencies>
</project>