Spring Boot配置Akademiks与Options双数据源提示url未指定报错如何解决

报错是两个问题共同导致的：

• 未关闭Spring Boot默认的数据源自动配置，自定义多数据源场景下，Spring Boot仍会尝试读取默认spring.datasource.*前缀的配置，你未配置默认数据源就会抛出找不到url的异常
• OptionsDbConfig类中数据源属性绑定前缀配置错误，无法正确读取application.properties中options数据源的url、账号密码等核心配置

1. 启动类排除自动配置 #

修改你的项目启动类，在@SpringBootApplication注解中排除数据源相关自动配置：

@SpringBootApplication(exclude = {
        DataSourceAutoConfiguration.class,
        HibernateJpaAutoConfiguration.class
})
public class AkademiksApplication {
    public static void main(String[] args) {
        SpringApplication.run(AkademiksApplication.class, args);
    }
}

2. 修正OptionsDbConfig配置 #

optionsDataSourceProperties的属性绑定前缀错误，需要调整为和Akademiks配置类相同的规则：

@Configuration
@EnableTransactionManagement
@EnableJpaRepositories(basePackages = "com.example.resource.akademiks.options.dao",
 entityManagerFactoryRef = "optionsEntityManagerFactory",
 transactionManagerRef = "optionsTransactionManager")
public class OptionsDbConfig {
    
    // 修正前缀：读取options数据源的基础属性（url、driver、账号密码）
    @Bean
    @ConfigurationProperties("spring.datasource.options")
    public DataSourceProperties optionsDataSourceProperties() {
        return new DataSourceProperties();
    }
    
    // 这里前缀不变，读取连接池专属配置
    @Bean
    @ConfigurationProperties("spring.datasource.options.configuration")
    public DataSource optionsDataSource() {
        return optionsDataSourceProperties().initializeDataSourceBuilder()
                .type(BasicDataSource.class).build();
    }
    
    @Bean(name = "optionsEntityManagerFactory")
    public LocalContainerEntityManagerFactoryBean 
    optionsEntityManagerFactory(EntityManagerFactoryBuilder builder) {
        Map<String, Object> jpaProps = new HashMap<>();
        jpaProps.put("hibernate.dialect", "org.hibernate.dialect.MySQL8Dialect");
        return builder
                .dataSource(optionsDataSource())
                .packages(MathsOptions.class, ChemistryOptions.class, PhysicsOptions.class)
                .properties(jpaProps)
                // 新增persistenceUnit避免冲突
                .persistenceUnit("options")
                .build();
    }
    
    @Bean
    public PlatformTransactionManager optionsTransactionManager(
            final @Qualifier("optionsEntityManagerFactory")
            LocalContainerEntityManagerFactoryBean optionsEntityManagerFactory
            ) {
        return new JpaTransactionManager(optionsEntityManagerFactory.getObject());
    }
}

3. 可选优化 #

建议在AkademiksDbConfig的akademiksEntityManagerFactory方法中也添加persistenceUnit配置，避免两个数据源的JPA上下文冲突：

@Primary
@Bean(name = "akademiksEntityManagerFactory")
public LocalContainerEntityManagerFactoryBean 
akademiksEntityManagerFactory(EntityManagerFactoryBuilder builder) {
    Map<String, Object> jpaProps = new HashMap<>();
    jpaProps.put("hibernate.dialect", "org.hibernate.dialect.MySQL8Dialect");
    return builder
            .dataSource(akademiksDataSource())
            .packages(Mathematics.class, Chemistry.class, Physics.class)
            .properties(jpaProps)
            .persistenceUnit("akademiks")
            .build();
}

修改完成后重新启动项目即可正常加载双数据源。

内容的提问来源于stack exchange，提问作者Chinedu