beanFactory 提供基本的功能 ApplicationContext 增加了特定的功能
beans的范围
singleton bean
Only one instance is ever created
prototype bean
A brand new bean instance is created
https://gitee.com/JCTechnology_963178841/spring-boot-enterprise-book
mysql与navivat上面的连接问题 https://www.jianshu.com/p/ec35d2e772b8 https://gitee.com/didispace/SpringBoot-Learning