解决spring-boot启动中碰到的问题：Cannot determine embedded database driver class for database type NONE

问题 如下：

2017-07-16 08:50:57.436  INFO 13524 --- [           main] c.p.p.web.PointshopWebApplication        : Starting PointshopWebApplication on MSI with PID 13524 (D:\javaProject\com.ppdai.pointshop\pointshop-web\target\classes started by yangliweng in D:\javaProject\com.ppdai.pointshop)

2017-07-16 08:50:57.436  INFO 13524 --- [           main] c.p.p.web.PointshopWebApplication        : No active profile set, falling back to default profiles: default

2017-07-16 08:50:57.478  INFO 13524 --- [           main] s.c.a.AnnotationConfigApplicationContext : Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@179bb86: startup date [Sun Jul 16 08:50:57 GMT+08:00 2017]; root of context hierarchy

2017-07-16 08:50:57.798  WARN 13524 --- [           main] o.m.s.mapper.ClassPathMapperScanner      : No MyBatis mapper was found in '[com.ppdai.pointshop.web.controller, com.ppdai.pointshop.web]' package. Please check your configuration.

2017-07-16 08:50:57.829  INFO 13524 --- [           main] .s.d.r.c.RepositoryConfigurationDelegate : Multiple Spring Data modules found, entering strict repository configuration mode!

2017-07-16 08:50:58.001  WARN 13524 --- [           main] o.h.v.m.ParameterMessageInterpolator     : HV000184: ParameterMessageInterpolator has been chosen, EL interpolation will not be supported

2017-07-16 08:50:58.151  WARN 13524 --- [           main] o.h.v.m.ParameterMessageInterpolator     : HV000184: ParameterMessageInterpolator has been chosen, EL interpolation will not be supported

2017-07-16 08:50:58.224  WARN 13524 --- [           main] s.c.a.AnnotationConfigApplicationContext : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Tomcat.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.tomcat.jdbc.pool.DataSource]: Factory method 'dataSource' threw exception; nested exception is org.springframework.boot.autoconfigure.jdbc.DataSourceProperties$DataSourceBeanCreationException: Cannot determine embedded database driver class for database type NONE. If you want an embedded database please put a supported one on the classpath. If you have database settings to be loaded from a particular profile you may need to active it (no profiles are currently active).

2017-07-16 08:50:58.240  INFO 13524 --- [           main] utoConfigurationReportLoggingInitializer :

Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled.

2017-07-16 08:50:58.240 ERROR 13524 --- [           main] o.s.b.d.LoggingFailureAnalysisReporter   :

***************************

APPLICATION FAILED TO START

***************************

Description:

Cannot determine embedded database driver class for database type NONE

Action:

If you want an embedded database please put a supported one on the classpath. If you have database settings to be loaded from a particular profile you may need to active it (no profiles are currently active).

Process finished with exit code 1

------------------------我是分割线------------------

网上 找到了所谓的解决 方法：

@SpringBootApplication(exclude = {

		DataSourceAutoConfiguration.class, HibernateJpaAutoConfiguration.class
},scanBasePackages = {"com.ppdai.pointshop.web.controller"}
)
public class PointshopWebApplication {

	public static void main(String[] args) {
		SpringApplication.run(PointshopWebApplication.class, args);
	}
}

　　但是很 遗憾 ，没用。

于是 用maven下载 好springboot 的源码，然后断点调试 进去 ，看看 是什么情况，最后 发现了问题的所在：

因为我这是一个新 项目 ，还 没有 配置数据源 ，但是我又想在 没配置数据源的情况 下去 启动项目，该怎么办呢 ？网上找到的方法是无效的，于是我做了一个大胆的猜测：肯定是某个地方加载了这个bean,因为 这是 一个新项目，所以 我觉得 启动加载的可能性很大，而启动 加载 只有 POM文件 里面的依赖才 有可能办到。下面 是 我的dependency依赖：

	<dependencies>
		<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-autoconfigure -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-autoconfigure</artifactId>
			<version>1.5.4.RELEASE</version>
		</dependency>
		<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot -->
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot</artifactId>
			<version>1.5.4.RELEASE</version>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-aop</artifactId>
			<version>1.5.4.RELEASE</version>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-redis</artifactId>
			<version>1.5.4.RELEASE</version>
		</dependency>
		<dependency>
			<groupId>org.mybatis.spring.boot</groupId>
			<artifactId>mybatis-spring-boot-starter</artifactId>
			<version>1.3.0</version>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
			<version>1.5.4.RELEASE</version>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-tomcat</artifactId>
			<version>1.5.4.RELEASE</version>
			<scope>provided</scope>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<version>1.5.4.RELEASE</version>
			<scope>test</scope>
		</dependency>

		<!-- https://mvnrepository.com/artifact/org.springframework/spring-core -->
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-core</artifactId>
			<version>4.3.9.RELEASE</version>
		</dependency>
		<!-- https://mvnrepository.com/artifact/org.springframework/spring-context -->
		<dependency>
			<groupId>org.springframework</groupId>
			<artifactId>spring-context</artifactId>
			<version>4.3.9.RELEASE</version>
		</dependency>

	</dependencies>

　　一个个排查，最后查到org.mybatis.spring.boot这个依赖 ，注释掉即可,可以发现，调试的时候 beannames明显少了很多。

<dependency>
   <groupId>org.mybatis.spring.boot</groupId>
   <artifactId>mybatis-spring-boot-starter</artifactId>
   <version>1.3.0</version>
</dependency>

最终，Spring Boot 启动成功！