the best description of the spring boot was from the spring boot official site: -> Spring Boot makes it easy to create stand-alone, production-grade Spring based Applications that you can “just run”...Most Spring Boot applications need very little Spring configuration. The traditional JEE and spring development was diffcult, hard to configure, spring boot was developed to simplified this type of work and help developers quickly build their environment based on the configuration over contract pattern, focus on the business logic and deploy to production ready environment.
Java language was introduced in 1995 but slowly evolved, first was used in the browser and then to the desktop, but was first widely accepted is the web applicaiton was introduced to the enterprise application domain, J2EE and Servlet/JSP technology was dominated in the application development ecosystem, but the J2EE was to complicated and spring was introduced to simpilify the web development in the J2EE world. but the underlying JDK and java language was almost slow down almost for then year after Oracle acquired Sun Microsystem, Jdk 6 was the most mature language in the 2000s, but JDK7/8 only add some nitch feature for the language, JDK 9/10 was need to big revolution to catch up with the modern development architecture. In the mobile first, cloud native application architecture, J2EE and Java was just the language was too old to meet the productivity and efficiciency of the modern language requirement, in the current stage, distributed computing and server-less computing is the new technology in the cloud native application architecture, but java multiple thread computing model and language extensibility was lack or lack of modern feature. Kotlin was introduced by JetBrains, their purpose was attracting the more and more Java and other language developer to this domain, kotlin adopt some new features from Go and Swift, help us more efficient on the web development and mobile development, and the ecosystem around kotlin growed very quickly, with the Google and IBM and also Pivotal support, more and more framework and environment will support kotlin.
Spring framework support the kotlin from version 5.0, the recently released spring-boot v2.0 also support kotlin, with the kotlin with spring-boot, you may see that the spring application development is also can utility the modern language feature and more prodctive.
Let's try our first example: Hello World.