加了這個配置，就會報以下錯誤（我是用Spring Tool Suite開發的）：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private javax.sql.DataSource org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.dataSource; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceAutoConfiguration$NonEmbeddedConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'dataSource' threw exception; nested exception is java.lang.IllegalStateException: Cannot load driver class: com.mysql.jdbc.Driver

at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1218) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:368) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1127) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1022) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1054) ~[spring-context-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:829) ~[spring-context-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538) ~[spring-context-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) ~[spring-boot-1.3.8.RELEASE.jar:1.3.8.RELEASE]

at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:760) [spring-boot-1.3.8.RELEASE.jar:1.3.8.RELEASE]

at org.springframework.boot.SpringApplication.createAndRefreshContext(SpringApplication.java:360) [spring-boot-1.3.8.RELEASE.jar:1.3.8.RELEASE]

at org.springframework.boot.SpringApplication.run(SpringApplication.java:306) [spring-boot-1.3.8.RELEASE.jar:1.3.8.RELEASE]

at org.springframework.boot.SpringApplication.run(SpringApplication.java:1185) [spring-boot-1.3.8.RELEASE.jar:1.3.8.RELEASE]

at org.springframework.boot.SpringApplication.run(SpringApplication.java:1174) [spring-boot-1.3.8.RELEASE.jar:1.3.8.RELEASE]

at org.springboot.sample.SpringBootSampleApplication.main(SpringBootSampleApplication.java:10) [classes/:na]

Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private javax.sql.DataSource org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.dataSource; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceAutoConfiguration$NonEmbeddedConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'dataSource' threw exception; nested exception is java.lang.IllegalStateException: Cannot load driver class: com.mysql.jdbc.Driver

at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:573) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

... 26 common frames omitted

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceAutoConfiguration$NonEmbeddedConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'dataSource' threw exception; nested exception is java.lang.IllegalStateException: Cannot load driver class: com.mysql.jdbc.Driver

at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1127) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1022) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1199) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1123) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1021) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:545) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

... 28 common frames omitted

Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [javax.sql.DataSource]: Factory method 'dataSource' threw exception; nested exception is java.lang.IllegalStateException: Cannot load driver class: com.mysql.jdbc.Driver

at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

... 40 common frames omitted

Caused by: java.lang.IllegalStateException: Cannot load driver class: com.mysql.jdbc.Driver

at org.springframework.util.Assert.state(Assert.java:392) ~[spring-core-4.2.8.RELEASE.jar:4.2.8.RELEASE]

at org.springframework.boot.autoconfigure.jdbc.DataSourceProperties.getDriverClassName(DataSourceProperties.java:165) ~[spring-boot-autoconfigure-1.3.8.RELEASE.jar:1.3.8.RELEASE]

at org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration$NonEmbeddedConfiguration.dataSource(DataSourceAutoConfiguration.java:121) ~[spring-boot-autoconfigure-1.3.8.RELEASE.jar:1.3.8.RELEASE]

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_101]

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_101]

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_101]

at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_101]

at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162) ~[spring-beans-4.2.8.RELEASE.jar:4.2.8.RELEASE]

... 41 common frames omitted