springboot整合druid连接池、mybatis实现多数据源动态切换

demo环境：

JDK 1.8 ，Spring boot 1.5.14

一整合durid

1.添加druid连接池maven依赖

<dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.0.29</version>
</dependency>

2.配置多数据源Druid

2.1 application.yml关于数据源配置

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    master:
      driver-class-name: com.mysql.jdbc.Driver
      url: jdbc:mysql://127.0.0.1:3306/db_test?characterEncoding=utf-8&autoReconnect=true&failOverReadOnly=false
      username: root
      password: root
      # 连接池初始化大小
      initialSize: 5
      # 配置获取连接等待超时的时间
      maxWait: 60000
      # 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
      timeBetweenEvictionRunsMillis: 60000
      # 配置一个连接在池中最小生存的时间，单位是毫秒
      minEvictableIdleTimeMillis: 30000
      validationQuery: SELECT 1 FROM DUAL
      testWhileIdle: true
      testOnBorrow: false
      testOnReturn: false
      # 打开PSCache，并且指定每个连接上PSCache的大小
      poolPreparedStatements: true
      connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
      # 合并多个DruidDataSource的监控数据
      useGlobalDataSourceStat: true
      filters: stat,wall,log4j
    slave:
      driver-class-name: com.mysql.jdbc.Driver
      url: jdbc:mysql://127.0.0.1:3306/db_slave?characterEncoding=utf-8&autoReconnect=true&failOverReadOnly=false
      username: root
      password: root
      # 连接池初始化大小
      initialSize: 5
      # 配置获取连接等待超时的时间
      maxWait: 60000
      # 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
      timeBetweenEvictionRunsMillis: 60000
      # 配置一个连接在池中最小生存的时间，单位是毫秒
      minEvictableIdleTimeMillis: 30000
      validationQuery: SELECT 1 FROM DUAL
      testWhileIdle: true
      testOnBorrow: false
      testOnReturn: false
      # 打开PSCache，并且指定每个连接上PSCache的大小
      poolPreparedStatements: true
      connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
      # 合并多个DruidDataSource的监控数据
      useGlobalDataSourceStat: true
      filters: stat,wall,log4

PS:若不配置filters在druid的SQL监控无法正常打印(如果选择的maven是直接继承springboot的druid-spring-boot-starter就不需要配置)

2.2 多数据源Bean的配置以及动态数据源的实现

@Configuration
@EnableTransactionManagement
public class DataSourceConfig {
    @Value("${spring.datasource.type}")
    private Class<? extends DataSource> dataSourceType;

    @Bean(name = "dbMasterDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.master")
    public DataSource dbTestDataSource(){
        return DataSourceBuilder.create().type(dataSourceType).build();
    }

    @Bean(name = "dbSlaveDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.slave")
    public DataSource dbSlaveDataSource(){
        return DataSourceBuilder.create().type(dataSourceType).build();
    }

    @Bean(name = "dataSource")
    @Primary
    public AbstractRoutingDataSource dataSource(){
        MasterSlaveRoutingDataSource masterSlaveRoutingDataSource = new MasterSlaveRoutingDataSource();
        Map<Object, Object> targetDataResources = new HashMap<>();
//        targetDataResources.put(DbContextHolder.DbType.MASTER, dbTestDataSource());
//        targetDataResources.put(DbContextHolder.DbType.SLAVE, dbSlaveDataSource());
        targetDataResources.put(DbEnum.MASTER, dbTestDataSource());
        targetDataResources.put(DbEnum.SLAVE, dbSlaveDataSource());
        masterSlaveRoutingDataSource.setDefaultTargetDataSource(dbSlaveDataSource());
        masterSlaveRoutingDataSource.setTargetDataSources(targetDataResources);
        masterSlaveRoutingDataSource.afterPropertiesSet();
        return masterSlaveRoutingDataSource;
    }
}

@Bean(name = "***")配置了两个数据源，将AbstractRoutingDataSource永@Primary注解标注，表示这个动态数据源是首选数据源

2.3 druid页面监控台配置

@WebFilter(filterName = "druidWebStatFilter", urlPatterns = "/*", initParams = {@WebInitParam(name = "exclusions", value = "*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico,/druid/*")})
public class DruidStatFilter extends WebStatFilter {
}

3.整合mybatis

3.1 mybatis配置文件

mybatis:
  mapper-locations: classpath*:/mapper/*.xml
  check-config-location: true
  type-aliases-package: com.springboot.datasource.entity
  config-location: classpath:mybatis-config.xml
pagehelper:
  auto-dialect: true
  close-conn: false
  reasonable: true
  helperDialect: mysql
  supportMethodsArguments: true
  params: count=countSql

4.切面注解配置

@Target({ElementType.TYPE,ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface DynamicDb {
    String value() default DbEnum.MASTER;
}

@Aspect
@Component
public class DbAspect implements Ordered {
    private static final Logger logger = LoggerFactory.getLogger(DbAspect.class);

    @Before("@annotation(masterDb)")
    public void beforeSwitch(JoinPoint joinPoint, MasterDb masterDb){
        System.out.println("进入之前");
    }

    @Around("@annotation(masterDb)")
    public Object proceed(ProceedingJoinPoint proceedingJoinPoint, MasterDb masterDb) throws Throwable{
        try {
            logger.info("set database connection to db_test only");
            DbContextHolder.setDbType(DbContextHolder.DbType.MASTER);
            Object result = proceedingJoinPoint.proceed();
            return result;
        }finally {
            DbContextHolder.clearDbType();
            logger.info("restore database connection");
        }
    }

    @Around("@annotation(slaveDb)")
    public Object proceed(ProceedingJoinPoint proceedingJoinPoint, SlaveDb slaveDb) throws Throwable{
        try {
            logger.info("set database connection to db_test only");
            DbContextHolder.setDbType(DbContextHolder.DbType.SLAVE);
            Object result = proceedingJoinPoint.proceed();
            return result;
        }finally {
            DbContextHolder.clearDbType();
            logger.info("restore database connection");
        }
    }
    @Around("@annotation(dynamicDb)")
    public Object proceed(ProceedingJoinPoint proceedingJoinPoint, DynamicDb dynamicDb) throws Throwable{
        try {
            logger.info("set database connection to {} only",dynamicDb.value());
            DbContextHolder.setDb(dynamicDb.value());
            Object result = proceedingJoinPoint.proceed();
            return result;
        }finally {
            DbContextHolder.clearDb();
            logger.info("restore database connection");
        }
    }


    @Override
    public int getOrder() {
        return 0;
    }
}

5. 启动主程序

@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
@ServletComponentScan
@EnableAspectJAutoProxy
public class BootDatasourceApplication {

    public static void main(String[] args) {
        SpringApplication.run(BootDatasourceApplication.class, args);
    }
}

按网上的需要将@MapperScan 加入到BootDatasourceApplication 类用来扫描mapper，demo中在Dao层用@Repository 注解，这里没添加@MapperScan 也没有报错。

demo下载(CSDN)

gitbub源码下载