<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.2.6</version>
</dependency>

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    druid:
      datasource1:
        url: jdbc:mysql://localhost:3306/master_db
        username: root
        password: password
        initial-size: 5
        min-idle: 5
        max-active: 20
        max-wait: 60000
      datasource2:
        url: jdbc:mysql://localhost:3306/slave_db
        username: root
        password: password
        initial-size: 5
        min-idle: 5
        max-active: 20
        max-wait: 60000

@Configuration
public class DataSourceConfig {

    @Bean
    @ConditionalOnProperty(prefix = "spring.datasource.druid", name = "datasource1")
    @ConfigurationProperties(prefix = "spring.datasource.druid.datasource1")
    public DataSource dataSource1() {
        return DruidDataSourceBuilder.create().build();
    }

    @Bean
    @ConditionalOnProperty(prefix = "spring.datasource.druid", name = "datasource2")
    @ConfigurationProperties(prefix = "spring.datasource.druid.datasource2")
    public DataSource dataSource2() {
        return DruidDataSourceBuilder.create().build();
    }

    @Bean
    @Primary
    public DataSource dynamicDataSource() {
        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        dynamicDataSource.setDefaultTargetDataSource(dataSource1());
        Map<Object, Object> targetDataSources = new HashMap<>();
        targetDataSources.put("dataSource1", dataSource1());
        targetDataSources.put("dataSource2", dataSource2());
        dynamicDataSource.setTargetDataSources(targetDataSources);
        return dynamicDataSource;
    }
}

public class DynamicDataSource extends AbstractRoutingDataSource {

    @Override
    protected Object determineCurrentLookupKey() {
        return DataSourceContextHolder.getDataSource();
    }
}

public class DataSourceContextHolder {

    private static final ThreadLocal<String> CONTEXT_HOLDER = new ThreadLocal<>();

    public static void setDataSource(String dataSource) {
        CONTEXT_HOLDER.set(dataSource);
    }

    public static String getDataSource() {
        return CONTEXT_HOLDER.get();
    }

    public static void clearDataSource() {
        CONTEXT_HOLDER.remove();
    }
}

import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.annotation.AfterReturning;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;
import org.aspectj.lang.annotation.Pointcut;
import org.springframework.stereotype.Component;

@Aspect
@Component
public class DataSourceAspect {
	// 方法或者類(lèi)上的橫切點(diǎn)
    @Pointcut("@annotation(dataSource) || @within(dataSource)")
    public void dataSourcePointcut(DataSource dataSource) {}

    @Before("dataSourcePointcut(dataSource)")
    public void switchDataSource(JoinPoint joinPoint, DataSource dataSource) {
        // 從注解中獲取數(shù)據(jù)源標(biāo)識(shí)
        String dataSourceKey = dataSource.value();
        // 切換到指定的數(shù)據(jù)源
        DataSourceContextHolder.setDataSourceType(dataSourceKey);
    }

    @AfterReturning(pointcut = "dataSourcePointcut(dataSource)", returning = "result")
    public void restoreDataSource(JoinPoint joinPoint, DataSource dataSource, Object result) {
        // 恢復(fù)默認(rèn)數(shù)據(jù)源（可選）
        DataSourceContextHolder.clearDataSourceType();
    }
}

/**
* 自定義注解
*/
@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface DataSource {

    String value() default "dataSource1";
}