demo地址：https://gitee.com/fhmj520/springboot-datasource.git

1.導(dǎo)入相對應(yīng)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.配置數(shù)據(jù)源鏈接

雙數(shù)據(jù)源.png

3.新建DynamicDataSourceConfig

DynamicDataSourceConfig.png

4.新建DynamicDataSource繼承AbstractRoutingDataSource,重寫determineCurrentLookupKey方法實現(xiàn)動態(tài)數(shù)據(jù)源

需要理解ThreadLocal仰冠，線程的局部變量，相當(dāng)于private static，供本線程內(nèi)存儲內(nèi)容

ThreadLocal.png

在DynamicDataSource中重寫構(gòu)造方法，在決定數(shù)據(jù)源前把數(shù)據(jù)源信息初始化完成并配置好

DynamicDataSource的重構(gòu)方法.png

5.設(shè)定多數(shù)據(jù)源的Names

新建DataSourceNames

public interface DataSourceNames {
  String FIRST = "first";
  String SECOND = "second";
}

6.需要啟動時初始化數(shù)據(jù)源信息，完成后面事務(wù)的初始化需要的依賴數(shù)據(jù)源Bean

所以在DynamicDataSourceConfig中進行配置

/**
 * 由于數(shù)據(jù)源的信息需要在初始化的時候加載啟動
 * @param firstDataSource
 * @param secondDataSource
 * @return
 */
@Bean
@Primary //優(yōu)先考慮，優(yōu)先考慮被注解的對象的注入
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.編寫多數(shù)據(jù)源的切面處理類和注解

AOP類

/**
 * 多數(shù)據(jù)源，切面處理類
 */
@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

在業(yè)務(wù)實現(xiàn)中進行注解調(diào)用的數(shù)據(jù)庫缚去，進行多數(shù)據(jù)源的切換，不涉及多事務(wù)

使用.png