Mybatis-Plus&&Druid多数据源配置

多数据源配置思路

• yml中配置多个数据源；
• 通过AOP自动切换不同的数据源；
• 配合Mybatis-plus使用

yml配置

spring:
  datasource:
    druid:
      db1:
        url: jdbc:mysql://10.168.1.118:3306/rd?useUnicode=true&characterEncoding=utf-8&useSSL=false
        username: root
        password: 123456
        driver-class-name: com.mysql.cj.jdbc.Driver
        #初始连接数 默认0
        initial-size: 10
        #最大连接数，默认8
        max-active: 30
        #最小闲置数
        min-idle: 10
        #获取连接的最大等待时间，单位毫秒
        max-wait: 2000
      db2:
        url: jdbc:postgresql://127.0.0.1:5432/postgres
        username: postgres
        password: 123456
        driver-class-name: org.postgresql.Driver
        #初始连接数 默认0
        initial-size: 10
        #最大连接数，默认8
        max-active: 30
        #最小闲置数
        min-idle: 10
        #获取连接的最大等待时间，单位毫秒
        max-wait: 2000

mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl # 打印SQL
  mapper-locations: classpath:mappers/**/*.xml

启动多个数据源  

@EnableTransactionManagement
@Configuration
@MapperScan("com.kuiper.mapper")
public class MybatisPlusConfig {

    @Bean
    public MybatisPlusInterceptor paginationInterceptor() {
        MybatisPlusInterceptor interceptor  = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }

    /**
     * mysql数据源
     *
     * @return
     */
    @Bean("db1DataSource")
    @ConfigurationProperties(prefix = "spring.datasource.druid.db1")
    public DataSource db1DataSource() {
        return DruidDataSourceBuilder.create().build();
    }

    /**
     * postgresql数据源
     *
     * @return
     */
    @Bean("db2DataSource")
    @ConfigurationProperties(prefix = "spring.datasource.druid.db2")
    public DataSource db2DataSource() {
        return DruidDataSourceBuilder.create().build();
    }

    /**
     * @description: 动态数据源配置
     * @param: db1DataSource mysql数据源，db2DataSource postgresql数据源
     * @return:
     * @author czl
     * @date: 2021/6/16 11:02
     */
    @Bean
    @Primary
    public DataSource multipleDataSource(@Qualifier("db1DataSource") DataSource db1DataSource, @Qualifier("db2DataSource") DataSource db2DataSource) {
        /** 创建动态数据源决策者 */
        DynamicDataSource dynamicDataSource = new DynamicDataSource();
        /** 存放多个数据源 */
        Map<Object, Object> targerDataSource = new HashMap<>(16);
        targerDataSource.put(DataSourceTypeEnum.db1DataSource.getValue(), db1DataSource);
        targerDataSource.put(DataSourceTypeEnum.db2DataSource.getValue(), db2DataSource);
        /** 讲多个数据源注入targetDataSources */
        dynamicDataSource.setTargetDataSources(targerDataSource);
        /** 默认数据源 */
        dynamicDataSource.setDefaultTargetDataSource(db1DataSource);
        return dynamicDataSource;
    }

    @Bean("sqlSessionFactory")
    public SqlSessionFactory sqlSessionFactory() throws Exception {
        /** 创建mybatis中的sqlSessionFactoryBean工厂 */
        MybatisSqlSessionFactoryBean sqlSessionFactory = new MybatisSqlSessionFactoryBean();
        /** 向sqlSessionFactoryBean工厂中注入数据源 */
        sqlSessionFactory.setDataSource(this.multipleDataSource(db1DataSource(), db2DataSource()));
        /** 创建MybatisConfiguration */
        MybatisConfiguration mybatisConfiguration = new MybatisConfiguration();
        mybatisConfiguration.setJdbcTypeForNull(JdbcType.NULL);
        /** 开启驼峰命名规则 */
        mybatisConfiguration.setMapUnderscoreToCamelCase(true);
        /** 是否开启缓存 */
        mybatisConfiguration.setCacheEnabled(false);
        sqlSessionFactory.setConfiguration(mybatisConfiguration);
        return sqlSessionFactory.getObject();
    }
}

枚举DataSourceTypeEnum类 

public enum DataSourceTypeEnum {

    /**
     * mysql数据源源
     */
    db1DataSource("db1DataSource"),
    /**
     * postgresql数据源
     */
    db2DataSource("db2DataSource");

    private String value;

    DataSourceTypeEnum(String value) {
        this.value = value;
    }

    public String getValue() {
        return value;
    }
}

动态决策数据源

@Slf4j
public class DynamicDataSource extends AbstractRoutingDataSource {

    /**
     * @description:  动态数据源决策
     * @param: null
     * @return:
     * @author
     * @date: 2021/6/16 11:09
     */
    @Override
    protected Object determineCurrentLookupKey() {
        String dataSourceType = DataSourceContextHolder.getDataSourceType();
        log.info("当前数据源为：{}", dataSourceType);
        return dataSourceType;
    }
}

 设置、添加、获取数据源

public class DataSourceContextHolder {


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

    /**
     * 设置数据源
     *
     * @param dataSourceTypeEnum
     */
    public static void setDataSourceType(DataSourceTypeEnum dataSourceTypeEnum) {
        CONTEXT_HOLDER.set(dataSourceTypeEnum.getValue());
    }

    /**
     * 取得当前数据源
     *
     * @return
     */
    public static String getDataSourceType() {
        return (String) CONTEXT_HOLDER.get();
    }

    /**
     * 清除上下文数据
     *
     * @return
     */
    public static void clearDataSourceType() {
        CONTEXT_HOLDER.remove();
    }
}

 AOP实现动态数据源的切换

@Component
@Order(-100)
@Slf4j
@Aspect
public class DataSourceAspect {

    @Pointcut("execution(* com.kuiper.mapper.db1..*.*(..))")
    private void db1Aspect() {
    }

    @Pointcut("execution(* com.kuiper.mapper.db2..*.*(..))")
    private void db2Aspect() {
    }

    @Before("db1Aspect()")
    public void db1DataSource() {
        log.info("切换数据源为：{}", DataSourceTypeEnum.db1DataSource.getValue());
        DataSourceContextHolder.setDataSourceType(DataSourceTypeEnum.db1DataSource);
    }

    @Before("db2Aspect()")
    public void db2DataSource() {
        log.info("切换数据源为：{}", DataSourceTypeEnum.db2DataSource.getValue());
        DataSourceContextHolder.setDataSourceType(DataSourceTypeEnum.db2DataSource);
    }

}

 项目工程结构

跨域请求配置

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

    @Override
    public void addCorsMappings(CorsRegistry registry) {
        /** 设置允许跨域路径 */
        registry.addMapping("/**")
                /** 设置允许跨域请求的域名 */
                .allowedOriginPatterns("*")
                /** 是否允许证书 不在默认开启 */
                .allowCredentials(true)
                /** 设置允许的方法 */
                .allowedMethods("*")
                /** 跨域允许时间 */
                .maxAge(3600);
    }
}