使用 dynamic-datasource 完成多数据源操作

本次操作是将达梦数据库的数据插入到MySQL数据库中。

准备工作

1. 创建一个 Spring Boot 项目
2. 添加依赖
3. 配置数据源属性

POM文件

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.32</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
            <version>3.5.2</version>
        </dependency>
        <!--  添加dm8 jdbc jar 包依赖-->
        <dependency>
            <groupId>com.dm</groupId>
            <artifactId>DmJdbcDriver</artifactId>
            <version>1.8.0</version>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.3.2</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

YML文件配置多数据源

spring:
  datasource:
    dynamic:
      druid:
        initial-size: 5
        min-idle: 5
        maxActive: 20
        # 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: 6000
        # 配置一个连接在池中最小生存的时间，单位是毫秒
        minEvictableIdleTimeMillis: 60000
        # 配置一个连接在池中最大生存的时间，单位是毫秒
        maxEvictableIdleTimeMillis: 900000
        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
        maxPoolPreparedStatementPerConnectionSize: 20
      primary: dm #设置默认的数据源或者数据源组,默认值即为dm
      strict: false #严格匹配数据源,默认false. true未匹配到指定数据源时抛异常,false使用默认数据源
      datasource:
        dm:
          driver-class-name: dm.jdbc.driver.DmDriver
          url: jdbc:dm://localhost:5236
          username: xxxx
          password: xxxxxxxxx
        mysql:
          driver-class-name: com.mysql.cj.jdbc.Driver # 3.2.0开始支持SPI可省略此配置
          url: jdbc:mysql://localhost:3306/lps?serverTimezone=GMT%2B8&useUnicode=true&characterEncoding=utf-8&useSSL=false&allowMultiQueries=true&allowPublicKeyRetrieval=true
          username: xxxxx
          password: xxxxxxxxxxx

实体类

@Data
public class CfdData implements Serializable {
    /**
     * 
     */
    @TableField(value = "TIME")
    private LocalDateTime time;

    /**
     * 
     */
    @TableField(value = "VAL")
    private String val;

    @TableField(exist = false)
    private static final long serialVersionUID = 1L;
}

DAO层

@Mapper
public interface CfdDataMapper extends BaseMapper<CfdData> {

    void insertForMysql(CfdData cfdData);

    Long selectCountFromMysql();

    List<CfdData> selectFromDm();

}

XML映射层（达梦的SQL语句需要带上模式名称，而MySQL不需要）

    <insert id="insertForMysql">
        INSERT INTO CFD_DATA (TIME, VAL)
        VALUES (#{time}, #{val});
    </insert>
    <select id="selectFromDm" resultType="com.lp.domain.CfdData">
        SELECT * FROM LPS.CFD_DATA
    </select>
    <select id="selectCountFromMysql" resultType="java.lang.Long">
        SELECT COUNT(1) FROM CFD_DATA
    </select>

Service接口层

/**
 * @author 阿水
 * @ClassName CfdDataMySql
 * @description: TODO
 * @date 2023年10月21日
 * @version: 1.0
 */
public interface CfdDataMySqlService extends IService<CfdData> {

    Long insertForMysql(List<CfdData> cfdData);
    Long selectCountFromMysql();
}

/**
* @author 19449
* @description 针对表【CFD_DATA】的数据库操作Service
* @createDate 2023-10-21 23:32:05
*/
public interface CfdDataService extends IService<CfdData> {
    List<CfdData> selectFromDm();
}

Service实现类(使用ds注解来选择数据源)

@Service
@DS("mysql")
public class CfdDataMySqlServiceImpl extends ServiceImpl<CfdDataMapper, CfdData>
        implements CfdDataMySqlService {
    @Resource
    private SqlSessionFactory sqlSessionFactory;
    @Resource
    private CfdDataMapper cfdDataMapper;
    @Override
    public Long insertForMysql(List<CfdData> cfdData) {
        SqlSession session = sqlSessionFactory.openSession(ExecutorType.BATCH);
        try{
            CfdDataMapper mapper = session.getMapper(CfdDataMapper.class);
            cfdData.forEach(item->{
                mapper.insertForMysql(item);
            });
            session.commit();
        }
        finally {
            session.close();
        }
        return (long) cfdData.size();
    }

    @Override
    public Long selectCountFromMysql() {
        return cfdDataMapper.selectCountFromMysql();
    }
}

/**
* @author 19449
* @description 针对表【CFD_DATA】的数据库操作Service实现
* @createDate 2023-10-21 23:32:05
*/
@Service
@DS("dm")
public class CfdDataServiceImpl extends ServiceImpl<CfdDataMapper, CfdData>
    implements CfdDataService {
    @Autowired
    private CfdDataMapper cfdDataMapper;

    @Override
    public List<CfdData> selectFromDm() {
        return cfdDataMapper.selectFromDm();
    }
}

测试代码

@SpringBootTest
class JdbcTemplateDemo1ApplicationTests {
    //达梦数据库
    @Resource
    CfdDataService dmService;
    //mysql数据库
    @Resource
    CfdDataMySqlService mySqlService;

    @Test
    void contextLoads() {
        List<CfdData> cfdData = dmService.selectFromDm();
        for (CfdData cfdDatum : cfdData) {
            System.out.println(cfdDatum);
        }
        System.out.println("本次DM数据数据条数为"+cfdData.size()+"条");
        Long countFromMysql = mySqlService.selectCountFromMysql();
        System.out.println("mysql当前条数为"+countFromMysql+"条");
        System.out.println("开始插入");
        mySqlService.insertForMysql(cfdData);
        System.out.println("插入完成");
        Long countAfterInsert = mySqlService.selectCountFromMysql();
        System.out.println("mysql插入完成后当前条数为"+countAfterInsert+"条");
        Long count = mySqlService.getBaseMapper().selectCount(null);
        /**
         * 这个走的是默认
         * primary: dm #设置默认的数据源或者数据源组,默认值即为dm
         */
        System.out.println("mybatisplus查询出来的count为"+count+"条");
    }

}

整体结构如下

结论以及注意事项：不指定的话会走默认数据源

注解	结果
没有@DS	默认数据源
@DS("dsName")	dsName可以为组名也可以为具体某个库的名称