Spring Boot WebApplicationType

last modified July 20, 2023

Spring Boot WebApplicationType tutorial presents various types of web applications in a Spring Boot application. The example shows how to set the WebApplicationType.

Spring Boot is a popular application framework for creating enterprise application in Java, Kotlin, or Groovy.


The WebApplicationType is an enumeration of possible types of web applications. There are three possible values:

Spring Boot example

In the following application, we define the web application type of a Spring Boot application.

├── main
│   ├── java
│   │   └── com
│   │       └── zetcode
│   │           └── Application.java
│   └── resources
└── test
    └── java

This is the project structure of the Spring Boot application.

plugins {
    id 'java'
    id 'org.springframework.boot' version '3.1.1'
    id 'io.spring.dependency-management' version '1.1.0'

group = 'com.zetcode'
version = '0.0.1-SNAPSHOT'

java {
    sourceCompatibility = '17'

repositories {

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-webflux'
    implementation 'org.springframework.boot:spring-boot-starter-web'

test {

In the build.gradle file, we have dependencies for a classic servlet and reactive web application.

package com.zetcode;

import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.WebApplicationType;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.reactive.function.server.RouterFunction;
import org.springframework.web.reactive.function.server.ServerResponse;

import static org.springframework.web.reactive.function.BodyInserters.fromValue;
import static org.springframework.web.reactive.function.server.RequestPredicates.GET;
import static org.springframework.web.reactive.function.server.RouterFunctions.route;
import static org.springframework.web.reactive.function.server.ServerResponse.ok;

public class Application {

    public static void main(String[] args) {

        new SpringApplicationBuilder(Application.class)

class MyController {

    public String hello() {

        return "Home page";

class MyRoutes {

    RouterFunction<ServerResponse> about() {
        return route(GET("/about"), request -> ok().body(fromValue("About page")));

class MyRunner implements CommandLineRunner {

    public void run(String... args) throws Exception {

        System.out.println("Hello there!");

In the Application, we define the Spring Boot application and set up a classic web rest point, a reactive route and a commandline runner.

new SpringApplicationBuilder(Application.class)

We define the web application type using the SpringApplicationBuilder. For the WebApplicationType.SERVLET, the reactive route is not available.

$ ./gradlew bootRun

We start the application.

$ curl localhost:8080/
Home page

The classic servlet rest point is active.

In this article we have worked with a Spring Boot WebApplicationType.


My name is Jan Bodnar and I am a passionate programmer with many years of programming experience. I have been writing programming articles since 2007. So far, I have written over 1400 articles and 8 e-books. I have over eight years of experience in teaching programming.

List all Spring Boot tutorials.