最近，配置项目，使用SpringBoot2.2.1，配置mybatis访问db，配好后，使用自定义的数据源。启动发生：
APPLICATION FAILED TO START *************************** Description: Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured. Reason: Failed to determine a suitable driver class Action: Consider the following: If you want an embedded database (H2, HSQL or Derby), please put it on the classpath. If you have database settings to be loaded from a particular profile you may need to activate it (no profiles are currently active).
虽然，我知道，是因为我没有在application.yml文件中配置：spring.datasource。但是因为我是自定义的数据源，配置项不在spring.datasource，所以希望，不配置spring.datasource，也能启动项目。单纯在@SpringBootApplication(exclude = {DataSourceAutoConfigure.class})中排除DataSourceAutoConfigure是不行的。
下面是解决方案：
方案1:
在自定义数据源中，添加自定义自动配置类。见下面的例子：
import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.EnableAspectJAutoProxy;
import javax.annotation.Resource;
import javax.sql.DataSource;
import java.util.Properties;
/**
* 自定义自动配置类
* 1. 自定义数据源，自定义数据源是为了，防止因为没有在配置文件中，配置spring.datasource，
* 出现：Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured.
* 2. 切面类，用来切换主从数据源
*
*/
@EnableAspectJAutoProxy
@Configuration
public class CustomDataSourceAutoConfiguration {
@Bean
@ConditionalOnMissingBean
public DataSource defaultDataSource() {
return new CustomDataSource());
}
}
@Bean
@ConditionalOnBean({DataSource.class})
public CustomDataSourceAspect CustomDsAspect() {
return new CustomDataSourceAspect();
}
}
别忘了，在META-INF/spring.factories文件中配置：
org.springframework.boot.autoconfigure.EnableAutoConfiguration= com.xxx.framework.datasource.masterslave.CustomDataSourceAutoConfiguration
方案2:
在启动类上，添加如下代码：
import com.lzj.framework.datasource.multi.MultiDatabaseMapperFactoryBean;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
@MapperScan(basePackages = {"com.xxx.test.dao"}, factoryBean = MultiDatabaseMapperFactoryBean.class)
public class LzjFrameworkTestApplication {
public static void main(String[] args) {
SpringApplication.run(LzjFrameworkTestApplication.class, args);
}
}
第一要在@SpringBootApplication中排除DataSourceAutoConfiguration类的配置；第二，要配置@MapperScan，在参数中指出，扫描标准@Mapper注解的dao接口的包位置，和自定义factoryBean的实现类。factoryBean需要自己实现，需要继承MapperFactoryBean接口。
当然，你要是不使用数据库，只需把DataSourceAutoConfiguration排除就可以了。
项目，就可以正常启动了。