Spring官方文档比较齐全，学习的过程中可以多参考官方文档，最权威的版本。
01、Spring Boot的一些官方链接
01.01 Spring Boot官网
https://spring.io/projects/spring-boot
01.02 spring-boot官方github
截至2019-10-20 周日，v2.2.0.RELEASE已发布（2019-10-17）
https://github.com/spring-projects/spring-boot
01.03 spring-boot发布tag
2.1.4.RELEASE:
https://github.com/spring-projects/spring-boot/releases/tag/v2.1.4.RELEASE
2.1.5.RELEASE:
https://github.com/spring-projects/spring-boot/releases/tag/v2.1.5.RELEASE
2.2.0.RELEASE:
https://github.com/spring-projects/spring-boot/releases/tag/v2.2.0.RELEASE
All RELEASE:
https://github.com/spring-projects/spring-boot/releases
01.04 spring-boot官方文档链接
2.1.5.RELEASE:
https://docs.spring.io/spring-boot/docs/2.1.5.RELEASE/reference/
2.1.5.RELEASE的html版本链接：
https://docs.spring.io/spring-boot/docs/2.1.5.RELEASE/reference/html/
2.1.5.RELEASE的htmlsingle版本链接：
https://docs.spring.io/spring-boot/docs/2.1.5.RELEASE/reference/htmlsingle/
2.1.5.RELEASE的pdf版本链接：
https://docs.spring.io/spring-boot/docs/2.1.5.RELEASE/reference/pdf/spring-boot-reference.pdf
最新版本：
https://docs.spring.io/spring-boot/docs/current/reference/
所有版本：
https://docs.spring.io/spring-boot/docs/
02、Spring Boot介绍
（以下来自官方文档spring-boot-reference，for 2.1.5.RELEASE，Page 25：8. Introducing Spring Boot）
Spring Boot makes it easy to create stand-alone, production-grade Spring-based Applications that you can run. We take an opinionated view of the Spring platform and third-party libraries, so that you can get started with minimum fuss. Most Spring Boot applications need very little Spring configuration.
You can use Spring Boot to create Java applications that can be started by using java -jar or more traditional war deployments. We also provide a command line tool that runs “spring scripts”.
Our primary goals are:
• Provide a radically faster and widely accessible getting-started experience for all Spring development.
• Be opinionated out of the box but get out of the way quickly as requirements start to diverge from the defaults.
• Provide a range of non-functional features that are common to large classes of projects (such as embedded servers, security, metrics, health checks, and externalized configuration).
• Absolutely no code generation and no requirement for XML configuration.
简单列出几点：
- 可以更简捷地创建生产级的单体应用
- 最小依赖，Spring相关依赖和第三方依赖使用默认配置
- 开箱即用
- 提供了一系列非功能性特性：内嵌服务器、安全管理、健康检测等
- 无需xml配置和代码生成。
初步感受就是：把Spring全家桶和很多的第三方依赖进行了 大整合 + 简化配置，也即是 默认配置 + IoC/DI + AOP + Spring MVC( + Web)。
03、系统要求
（以下来自官方文档spring-boot-reference，for 2.1.5.RELEASE，Page 26：9. System Requirements）
当前基于2.1.5.RELEASE版本（2019-05-15发布）进行学习。Spring Boot 2.1.5.RELEASE要求Java 8，兼容至Java 11；Spring版本则是5.1.7.RELEASE或以上。
构建工具的支持如下：
Build Tool | Version |
Maven | 3.3+ |
Gradle | 4.4+ |
内置容器及对应Servlet支持版本如下：
Name | Servlet Version |
Tomcat 9.0 | 4.0 |
Jetty 9.4 | 3.1 |
Undertow 2.0 | 4.0 |
以上就是本次学习的初步记录。