Step 04

Author: Ranga Rao Karanam

Step01.md

@@ -1,17 +1,17 @@
 ##What You Will Learn during this Step:
-- Set up an Maven Project with Eclipse. Intellij Link : https://www.jetbrains.com/help/idea/2016.2/getting-started-with-maven.html#create_maven_project
+- Set up an Maven Project with Eclipse. 
+ - Intellij Link : https://www.jetbrains.com/help/idea/2016.2/getting-started-with-maven.html#create_maven_project
 - Include dependencies needed for Spring Boot.
- - spring-boot-starter-web
- - spring-boot-maven-plugin
+ - spring-boot-starter-web : starter for building applications with Spring MVC. Tomcat is default embedded container.
+ - spring-boot-maven-plugin : Enable running application in-place and also building a jar/war to run later!
 - Launch Your First Spring Boot Application.
 
 ##Cool thing to note!
 Without a lot of configuration, we are up and running with a web application
 - Refer https://github.com/in28minutes/SpringMvcStepByStep/blob/master/Step01.md and https://github.com/in28minutes/SpringMvcStepByStep/blob/master/Step11.md to understand the sort of stuff - web.xml, dispatcher servlet configuration, maven dependency management and plugins - that are need to launch a typical web application without Spring Boot!
 
 ##What You Will NOT Learn during this Step:
-- Spring Boot does a lot of magic. This magic is called Auto Configuration.
-- We will discuss about different terms related to Spring Boot - Starter Parent, Starter projects, Auto configuration - in depth during our first 10 steps.
+- Spring Boot does a lot of magic. This magic is called Auto Configuration. We will discuss about different terms related to Spring Boot - Starter Parent, Starter projects, Auto configuration - in depth during our first 10 steps.
 - As far as this step is concerned, we will focus on getting up and running with Spring Boot. We will understand all the magic a little later. 
 - We will copy a lot of code in this step - just to avoid typos
 

Step02.md

@@ -1,10 +1,11 @@
 ##What You Will Learn during this Step:
 - Lets add a RestController with a dependency and see Spring Boot Magic live
 
-##Quick Spring Primer
+##Quick Spring and Spring MVC Primer
 - What is dependency?
 - @Component
 - @Autowired
+- @RestController
 
 ## Useful Snippets and References
 

Step03.md

@@ -1,19 +1,14 @@
 ##What You Will Learn during this Step:
-- First installment of how magic happens with Spring Boot. As a Spring Boot developer, you need to understand whats happening beneath the hood of Spring Boot! 
-- Understand Starter Parent
-- How to override things defined in Starter Parent
+- First installment of revealing how magic happens with Spring Boot. As a Spring Boot developer, you need to understand what's happening beneath the hood of Spring Boot! 
+- spring-boot-starter-web : starter for building applications with Spring MVC. Tomcat is default embedded container.
+- We already added this starter in the first step! Now we will explore the features it provides
 
-##Starter Parent
-- Dependency Versions
-- Java Versions
-- Default Plugins
-
-## Useful Snippets and References
-First Snippet
-```
-    <parent>
-        <groupId>org.springframework.boot</groupId>
-        <artifactId>spring-boot-starter-parent</artifactId>
-        <version>1.4.0.RELEASE</version>
-    </parent>
-```
+##spring-boot-starter-web
+- Spring Boot Starter Web brings all dependencies needed to build normal and RESTful web applications. Look at the dependency tree. 
+ - All the dependencies are added in because of spring-boot-starter-web
+ - Also look at /META-INF/spring.provides inside the spring-boot-starter-web.jar
+- Spring Boot Starter Web auto configures things needed to startup a web application. Look at the log
+ - Mapping servlet: 'dispatcherServlet' to [/]
+ - Mapped "{[/error]}" onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
+ - Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
+ - Look at package org.springframework.boot.autoconfigure.web in spring-boot-autoconfigure-*.jar