demo地址：https://gitee.com/fhmj520/springboot-datasource.git
1.导入相对应的pom文件
<!--aop-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<!--mybatis plus-->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.0.1</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<!--druid-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.10</version>
</dependency>
2.配置数据源链接
双数据源.png
3.新建DynamicDataSourceConfig
DynamicDataSourceConfig.png
4.新建DynamicDataSource继承AbstractRoutingDataSource,重写determineCurrentLookupKey方法实现动态数据源
需要理解ThreadLocal，线程的局部变量，相当于private static，供本线程内存储内容
ThreadLocal.png
在DynamicDataSource中重写构造方法，在决定数据源前把数据源信息初始化完成并配置好
DynamicDataSource的重构方法.png
5.设定多数据源的Names
新建DataSourceNames
public interface DataSourceNames {
String FIRST = "first";
String SECOND = "second";
}
6.需要启动时初始化数据源信息，完成后面事务的初始化需要的依赖数据源Bean
所以在DynamicDataSourceConfig中进行配置
/**
* 由于数据源的信息需要在初始化的时候加载启动
* @param firstDataSource
* @param secondDataSource
* @return
*/
@Bean
@Primary //优先考虑，优先考虑被注解的对象的注入
public DynamicDataSource dataSource(DataSource firstDataSource,
DataSource secondDataSource){
Map<Object,Object> targetDataSources = new HashMap<>();
targetDataSources.put(DataSourceNames.FIRST,firstDataSource);
targetDataSources.put(DataSourceNames.SECOND,secondDataSource);
return new DynamicDataSource(firstDataSource,targetDataSources);
}
7.编写多数据源的切面处理类和注解
AOP类
/**
* 多数据源，切面处理类
*/
@Aspect
@Component
public class DataSourceAspect implements Ordered {
protected Logger logger = LoggerFactory.getLogger(getClass());
@Pointcut("@annotation(com.example.datasource.DataSource)")
public void dataSourcePointCut(){}
@Around("dataSourcePointCut()")
public Object around(ProceedingJoinPoint point) throws Throwable {
MethodSignature signature = (MethodSignature) point.getSignature();
Method method = signature.getMethod();
DataSource ds = method.getAnnotation(DataSource.class);
if(ds == null){
DynamicDataSource.setDataSource(DataSourceNames.FIRST);
logger.debug("set datasource is " + DataSourceNames.FIRST);
}else {
DynamicDataSource.setDataSource(ds.name());
logger.debug("set datasource is " + ds.name());
}
try {
return point.proceed();
} finally {
DynamicDataSource.clearDataSource();
logger.debug("clean datasource");
}
}
@Override
public int getOrder() {
return 1;
}
}
DataSource注解
DataSource注解.png
8.使用
在业务实现中进行注解调用的数据库，进行多数据源的切换，不涉及多事务
使用.png
