Create a Web Application using Spring Boot

Overview

The tutorial illustrates how to create a Web Application with Spring. We’ll look into the Spring Boot solution for creating the application.

We’ll primarily use Java configuration in this tutorial.

Pre-requisties

JDK 1.8
Maven
IDE (for ease of use)

Getting Started

First, we’ll add the required dependencies and plugins in pom.xml

We will use the dependencyManagement to define a standard version of an artifact to use across multiple projects.

We will import the version of artifacts defined in spring-boot-starter-parent.

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.1.3.RELEASE</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

Now we'll add the spring-boot-starter-web dependency.

Spring Boot Starter Web includes:

spring-web module
spring-webmvc module
tomcat starter

Spring-web & Spring-webmvc are required for spring applications while tomcat starter is required to run web applications directly without explicitly installing any server.

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
</dependencies>

Spring Boot Maven Plugin provides Spring Boot support in Maven, letting you package executable jar or war archives and run an application “in-place”.

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

Creating a Spring Boot Application

Create a class with the main method. Annotate the class with @SpringBootApplication. Call the run method of SpringApplication class

package com.tutorialflix.spring.web;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringBootWebApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringBootWebApplication.class, args);
    }
}

@SpringBootApplication includes the functionality of following annotations:

By default, it will perform the component scan in the base package. So make sure SpringBootWebApplication class is present in the base package.

Creating a Web Controller

Create a class with a meaningful name based on your requirement & annotate the class with @Controller.

package com.tutorialflix.spring.web.contrroller;

import org.springframework.stereotype.Controller;

@Controller
public class MyWebController {


}

Create a method to accept requests

Create a method named home to accept the request on '/' URL and show the index.html

package com.tutorialflix.spring.web.contrroller;

import org.springframework.stereotype.Controller;

@Controller
public class MyWebController {

    @GetMapping("/")
    public String home() {
        return "index.html";
    }

}

Create a webpage to display

Create a public folder inside resources folder of the application and create a file named index.html.

<html>
    <body>
        <h1>Welcome to TutorialFlix.</h1>
    </body>
</html>

Configure application using a properties file

Create a file application.properties inside resources folder of the application and following properties.

server.port=8081
logging.level.org.springframework.web=DEBUG

server.port : to change the default port 8080 to any other port number.

logging.level.org.springframework.web : to change the log level default INFO to DEBUG

Run the web application

$ mvn spring-boot:run

Test

Goto localhost:8081