01 - Creating a Spring Boot project

springboot

web

REST

Getting started with Spring Boot

Introduction

Springboot is a Java framework that uses annotations to add functionalities to the SE packages

Spring boot project

Creating a new project

Go to the Spring initializr page to prepare a simple Maven project with the required dependencies:

Spring Web
Spring Boot DevTools
Lombok
Thymeleaf
H2 Database
Spring JDBC
etc…

After that, click the Generate button to download a Zip file with the project structure.

Creating controllers

REST controller

Use the following annotations to create a REST controller:

HelloRestController.java

package com.protoss.myfirstspring.controllers;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloRestController {

    @GetMapping("/hellorest")
    public String HelloWorld() {
        return "Hello World from the REST Controller!";
    }
}

where:

@RestController: this marks the class as the root of the REST controller
@GetMapping("/${action}"): maps the method to the given REST action

Web controller

Use the following annotations to create a Web controller:

HelloWebController.java

package com.protoss.myfirstspring.controllers;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class HelloWebController {

    // define handled path
    @RequestMapping("/helloweb")
    public String helloHandler() {
        return "hello.html";
    }
}