It covers the core concepts and key functions of Spring framework, including the use of inversion of control (IOC) container, the principle and practice of aspect oriented programming (AOP), the way and implementation of transaction management, the process and controller working mechanism of Spring MVC, and in-depth research on data access, security, boot automatic configuration in Spring. In addition, it also includes the application of Spring event mechanism, advanced topics such as cache abstraction and responsive programming, and in-depth discussion on the programming style and design pattern of Spring source code.