前言

博主近日在写springboot2.x（2.1.3）jdbc/jpa 多数据源的案例，运行代码时报错

jdbcUrl is required with driverClassName

原因

查阅了资料，发现还是springboot最细2.x版的原因

贴出两个关键配置：
application.yml:

spring:
  datasource:
    master:
      username: root
      password: 123456
      url: jdbc:mysql://192.168.145.131:3306/test
      driver-class-name: com.mysql.cj.jdbc.Driver
    slave:
      username: root
      password: 123456
      url: jdbc:mysql://192.168.145.131:3306/test2
      driver-class-name: com.mysql.cj.jdbc.Driver
  jpa:
    properties:
      hibernate:
        hbm2ddl:
          auto: update

config/DataSource:

    @Primary
    @Bean(name = "masterDataSource")
    @Qualifier("masterDataSource")
    @ConfigurationProperties(prefix="spring.datasource.master")
    public DataSource masterDataSource() {
        return DataSourceBuilder.create().build();
    }

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

    @Bean(name = "masterJdbcTemplate")
    @Qualifier("masterJdbcTemplate")
    public JdbcTemplate masterJdbcTemplate(@Qualifier("masterDataSource") DataSource dataSource) {
        return new JdbcTemplate(dataSource);
    }

    @Bean(name = "slaveJdbcTemplate")
    @Qualifier("slaveJdbcTemplate")
    public JdbcTemplate slaveJdbcTemplate(@Qualifier("slaveDataSource") DataSource dataSource) {
        return new JdbcTemplate(dataSource);
    }

这样的配置在springboot之前运行完全没问题，但是springboot升级2.0后，必须要配置jdbc-url才可以或者采取一种转换的方式。

贴上官方解释文档：

https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#howto-configure-a-datasource

两种解决方案如下：

方案一

直接改application.yml

spring:
  datasource:
    master:
      username: root
      password: 123456
      jdbc-url: jdbc:mysql://192.168.145.131:3306/test
      driver-class-name: com.mysql.cj.jdbc.Driver
    slave:
      username: root
      password: 123456
      jdbc-url: jdbc:mysql://192.168.145.131:3306/test2
      driver-class-name: com.mysql.cj.jdbc.Driver
  jpa:
    properties:
      hibernate:
        hbm2ddl:
          auto: update

url改为jdbc-url即可。非常简单。

方案二

此方案折腾点，不过，这样配置文件至少不用动了

修改数据源配置文件
config/DataSource:

    //master库
    @Primary
    @Bean(name = "masterDataSourceProperties")
    @Qualifier("masterDataSourceProperties")
    @ConfigurationProperties(prefix = "spring.datasource.master")
    public DataSourceProperties masterDataSourceProperties() {
        return new DataSourceProperties();
    }

    @Primary
    @Bean(name = "masterDataSource")
    @Qualifier("masterDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.master")
    public DataSource masterDataSource(@Qualifier("masterDataSourceProperties") DataSourceProperties dataSourceProperties) {
        return dataSourceProperties.initializeDataSourceBuilder().build();
    }

    //slave库
    @Bean(name = "slaveDataSourceProperties")
    @Qualifier("slaveDataSourceProperties")
    @ConfigurationProperties(prefix = "spring.datasource.slave")
    public DataSourceProperties slaveDataSourceProperties() {
        return new DataSourceProperties();
    }

    @Bean(name = "slaveDataSource")
    @Qualifier("slaveDataSource")
    @ConfigurationProperties(prefix = "spring.datasource.slave")
    public DataSource slaveDataSource(@Qualifier("slaveDataSourceProperties") DataSourceProperties dataSourceProperties) {
        return dataSourceProperties.initializeDataSourceBuilder().build();
    }

可以看出，我们对两个数据源分别使用了masterDataSourceProperties和slaveDataSourceProperties进行配置的转换。