spring boot配置多数据源（静态和动态数据源）

背景

在开发过程中，很多时候都会有垮数据库操作数据的情况，需要同时配置多套数据源，即多个数据库，保证不同的业务在不同的数据库执行操作，通过mapper来灵活的切换数据源。

本文以sqlserver和mysql混合数据源配置为例。

配置多数据源方案

1、通过mapper配置数据源

2、配置动态数据源

具体实现

1）、 通过mapper配置数据源

（1）maven配置

        
            org.springframework.boot
            spring-boot-starter-jdbc
        

        
            com.microsoft.sqlserver
            mssql-jdbc
        

        
            com.baomidou
            mybatis-plus-boot-starter
        

        
            com.baomidou
            mybatis-plus
        

        
            mysql
            mysql-connector-java
        

（2）服务配置文件，application.yml

server:
  port: 9900
spring:
  datasource:
    db1:
      type: com.zaxxer.hikari.HikariDataSource
      driver-class-name: com.microsoft.sqlserver.jdbc.SQLServerDriver
      jdbc-url: jdbc:sqlserver://localhost:10009;DatabaseName=test
      username: sa
      password: 654321



    db2:
      type: com.zaxxer.hikari.HikariDataSource
      driver-class-name: com.mysql.cj.jdbc.Driver
      jdbc-url: jdbc:mysql://localhost:3306/test2?useUnicode=true&useSSL=false&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai&rewriteBatchedStatements=true&allowMultiQueries=true
      username: root
      password: 123456

（3）添加数据库配置

@Configuration
public class DataSourceConfig {

    @Bean(name = "maindb")
    @Primary
    @ConfigurationProperties(prefix = "spring.datasource.db1")
    public DataSource businessDbDataSource() {
        return new HikariDataSource();
    }

    @Bean(name = "seconddb")
    @ConfigurationProperties(prefix = "spring.datasource.db2")
    public DataSource newhomeDbDataSource() {
        return new HikariDataSource();
    }
}

（4）单独配置每个数据源信息

注意：@Primary该注解理解为默认数据源

包路径配置可对比参考后面的项目结构截图

@Configuration
@MapperScan(basePackages = {"com.gxin.datasource.dao.maindb"}, sqlSessionFactoryRef = "sqlSessionFactoryMaindb")
public class DatasourceMainConfig {

    @Autowired
    @Qualifier("maindb")
    private DataSource dataSourceMaindb;

    @Bean
    @Primary
    public SqlSessionFactory sqlSessionFactoryMaindb() throws Exception {
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        factoryBean.setDataSource(dataSourceMaindb);
        factoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/maindb/*.xml"));
        // 打印sql日志
        // org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        // configuration.setLogImpl(StdOutImpl.class);
        // factoryBean.setConfiguration(configuration);
        return factoryBean.getObject();
    }

    @Bean
    @Primary
    public SqlSessionTemplate sqlSessionTemplateMaindb() throws Exception {
        return new SqlSessionTemplate(sqlSessionFactoryMaindb());
    }
}

@Configuration
@MapperScan(basePackages = {"com.gxin.datasource.dao.seconddb"}, sqlSessionFactoryRef = "sqlSessionFactorySeconddb")
public class DatasourceSecondConfig {
    @Autowired
    @Qualifier("seconddb")
    private DataSource dataSourceSeconddb;

    @Bean
    public SqlSessionFactory sqlSessionFactorySeconddb() throws Exception {
        SqlSessionFactoryBean factoryBean = new SqlSessionFactoryBean();
        factoryBean.setDataSource(dataSourceSeconddb);
        factoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/seconddb/*.xml"));
        // 打印sql日志
        // org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        // configuration.setLogImpl(StdOutImpl.class);
        // factoryBean.setConfiguration(configuration);
        return factoryBean.getObject();
    }

    @Bean
    public SqlSessionTemplate sqlSessionTemplateSeconddb() throws Exception {
        return new SqlSessionTemplate(sqlSessionFactorySeconddb());
    }
}

（5）根据每个单独的数据源的配置信息搭建mapper接口和mapper.xml文件

（6）配置mapper多数据源完成，下图为完整的项目结构

2）、 配置动态数据源

（1）maven配置

        
            org.springframework.boot
            spring-boot-starter-jdbc
        

        
            org.springframework.boot
            spring-boot-starter-aop
        

        
            com.microsoft.sqlserver
            mssql-jdbc
        

        
            com.baomidou
            mybatis-plus-boot-starter
        

        
            com.baomidou
            mybatis-plus
        

        
            mysql
            mysql-connector-java
        

（2）服务配置文件，application.yml

server:
  port: 9901
spring:
  main:
    allow-bean-definition-overriding: true
  datasource:
    db1:
      type: com.zaxxer.hikari.HikariDataSource
      driver-class-name: com.microsoft.sqlserver.jdbc.SQLServerDriver
      jdbc-url: jdbc:sqlserver://localhost:10009;DatabaseName=test
      username: sa
      password: 654321



    db2:
      type: com.zaxxer.hikari.HikariDataSource
      driver-class-name: com.mysql.cj.jdbc.Driver
      jdbc-url: jdbc:mysql://localhost:3306/test2?useUnicode=true&useSSL=false&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai&rewriteBatchedStatements=true&allowMultiQueries=true
      username: root
      password: 123456

（3）添加数据源列表

public interface DataSourceConstant {
    /**
     * 默认数据库
     */
    String MAIN = "MAIN";

    /**
     * 第二数据库
     */
    String SECOND = "SECOND";
}

（4）动态数据源数据库信息配置

@Configuration
@EnableAutoConfiguration(exclude = { DataSourceAutoConfiguration.class })
public class DynamicDataSourceConfig {

    // 核心数据库
    @Bean(name = DataSourceConstant.MAIN)
    @ConfigurationProperties(prefix = "spring.datasource.db1")
    public DataSource getMAINDataSource() {
        return new HikariDataSource();
    }

    // 第二数据库
    @Bean(name = DataSourceConstant.SECOND)
    @ConfigurationProperties(prefix = "spring.datasource.db2")
    public DataSource getSECONDDataSource() {
        return new HikariDataSource();
    }

    @Bean
    @Primary
    public DataSource dynamicDataSource() {
        Map dataSourceMap = new HashMap<>();
        dataSourceMap.put(DataSourceConstant.MAIN, getMAINDataSource());
        dataSourceMap.put(DataSourceConstant.SECOND, getSECONDDataSource());
        //设置动态数据源
        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        dynamicDataSource.setTargetDataSources(dataSourceMap);
        dynamicDataSource.setDefaultTargetDataSource(getMAINDataSource());

        return dynamicDataSource;
    }
}

（5）添加动态数据源策略获取配置，继承AbstractRoutingDataSource

@Component
public class DynamicDataSource extends AbstractRoutingDataSource {
    @Override
    protected Object determineCurrentLookupKey() {
        // 此处暂时返回固定 master 数据源, 后面按动态策略修改
        return DynamicDataSourceContextHolder.getContextKey();
    }
}

（6）数据源切换策略配置

public class DynamicDataSourceContextHolder {
    /**
     * 动态数据源名称上下文
     */
    private static final ThreadLocal DATASOURCE_CONTEXT_KEY_HOLDER = new ThreadLocal<>();

    /**
     * 设置/切换数据源
     */
    public static void setContextKey(String key) {
        DATASOURCE_CONTEXT_KEY_HOLDER.set(key);
    }

    /**
     * 获取数据源名称
     */
    public static String getContextKey() {
        String key = DATASOURCE_CONTEXT_KEY_HOLDER.get();
        return key == null ? DataSourceConstant.MAIN : key;
    }

    /**
     * 删除当前数据源名称
     */
    public static void removeContextKey() {
        DATASOURCE_CONTEXT_KEY_HOLDER.remove();
    }
}

(6.1) 这里写掉了，补充数据库会话配置

@Configuration
public class SqlSessionConfig {
    @Autowired
    private DynamicDataSource source;

    public SqlSessionConfig() {
    }

    @Bean(name = {"sqlSessionFactoryBean"})
    public SqlSessionFactoryBean getSessionFactory() throws Exception {
        SqlSessionFactoryBean factory = new SqlSessionFactoryBean();
        factory.setDataSource(this.source);
        factory.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath:mapper/*.xml"));
        // 打印sql日志
        org.apache.ibatis.session.Configuration configuration = new org.apache.ibatis.session.Configuration();
        configuration.setLogImpl(StdOutImpl.class);
        factory.setConfiguration(configuration);
        return factory;
    }

    @Bean(name = {"sqlSession"})
    public SqlSessionTemplate getSqlSession() throws Exception {
        return new SqlSessionTemplate(Objects.requireNonNull(getSessionFactory().getObject()));
        // SqlSessionFactory factory = this.getSessionFactory().getObject();
        // return new SqlSessionTemplate(factory, ExecutorType.BATCH);
    }

    @Bean
    public DataSourceTransactionManager getDataSourceTransaction() {
        DataSourceTransactionManager manager = new DataSourceTransactionManager();
        manager.setDataSource(this.source);
        return manager;
    }
}

(7) 添加切换数据源标识注解，默认为MAIN数据源

@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface DBS {

    /**
     * 数据源名称
     */
    String value() default DataSourceConstant.MAIN;
}

（8）通过配置的数据源标识注解，动态切换数据源

@Aspect
@Component
public class DynamicDataSourceAspect {

    @Pointcut("@annotation(com.gxin.dynamicdatasource.config.DBS)")
    public void dataSourcePointCut() {

    }

    @Around("dataSourcePointCut()")
    public Object around(ProceedingJoinPoint joinPoint) throws Throwable {
        String dsKey = getDSAnnotation(joinPoint).value();
        DynamicDataSourceContextHolder.setContextKey(dsKey);
        try {
            return joinPoint.proceed();
        } finally {
            DynamicDataSourceContextHolder.removeContextKey();
        }
    }

    /**
     * 根据类或方法获取数据源注解
     */
    private DBS getDSAnnotation(ProceedingJoinPoint joinPoint) {
        Class targetClass = joinPoint.getTarget().getClass();
        DBS dsAnnotation = targetClass.getAnnotation(DBS.class);
        // 先判断类的注解，再判断方法注解
        if (Objects.nonNull(dsAnnotation)) {
            return dsAnnotation;
        } else {
            MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature();
            return methodSignature.getMethod().getAnnotation(DBS.class);
        }
    }
}

（9）到此动态数据源配置完成，一下的为使用情况，需要使用哪个数据源添加注解配置即可

@Repository
public interface TestMapper {

    int getModelcount();

    @DBS(DataSourceConstant.SECOND)
    int getUsercount();

}

（10）service层

@Service
public class ServiceInfo {

    @Autowired
    private TestMapper mainMapper;


    public void datasource() {
        int modelcount = mainMapper.getModelcount();
        System.out.println(modelcount);

        int usercount = mainMapper.getUsercount();
        System.out.println(usercount);
    }
}

（11）mapper. xml结构目录

（12）完整的项目结构截图

收工图