Skip to content
Serving Web Content with Spring MVC :: Learn how to create a web page with Spring MVC and Thymeleaf.
Java HTML Shell
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Permalink
Type Name Latest commit message Commit time
Failed to load latest commit information.
complete
images Upgraded to Spring Boot 2.2 Dec 10, 2019
initial Upgraded to Spring Boot 2.2 Dec 10, 2019
test Convert to mvn compile for initial codeset Feb 19, 2014
.gitignore
.travis.yml Updated to @openjdk. Aug 12, 2019
CONTRIBUTING.adoc Add CONTRIBUTING doc Jun 27, 2016
LICENSE.code.txt Add ASLv2 license for the code in this repo Aug 16, 2013
LICENSE.writing.txt Apply http://creativecommons.org/licenses/by-nd/3.0/ to written work … Aug 16, 2013
README.adoc Upgraded to Spring Boot 2.2 Dec 10, 2019

README.adoc

This guide walks you through the process of creating a “Hello, World” web site with Spring.

What You Will Build

You will build an application that has a static home page and that will also accept HTTP GET requests at: http://localhost:8080/greeting.

It will respond with a web page that displays HTML. The body of the HTML will contain a greeting: “Hello, World!”

You can customize the greeting with an optional name parameter in the query string. The URL might then be http://localhost:8080/greeting?name=User.

The name parameter value overrides the default value of World and is reflected in the response by the content changing to “Hello, User!”

Starting with Spring Initializr

For all Spring applications, you should start with the Spring Initializr. The Initializr offers a fast way to pull in all the dependencies you need for an application and does a lot of the setup for you. This example needs the Spring Web, Thymeleaf, and Spring Boot DevTools dependencies. The following image shows the Initializr set up for this sample project:

initializr
Note
The preceding image shows the Initializr with Maven chosen as the build tool. You can also use Gradle. It also shows values of com.example and serving-web-content as the Group and Artifact, respectively. You will use those values throughout the rest of this sample.

The following listing shows the pom.xml file that is created when you choose Maven:

link:initial/pom.xml[]

The following listing shows the build.gradle file that is created when you choose Gradle:

link:initial/build.gradle[]

Create a Web Controller

In Spring’s approach to building web sites, HTTP requests are handled by a controller. You can easily identify the controller by the @Controller annotation. In the following example, GreetingController handles GET requests for /greeting by returning the name of a View (in this case, greeting). A View is responsible for rendering the HTML content. The following listing (from src/main/java/com/example/servingwebcontent/GreetingController.java) shows the controller:

link:complete/src/main/java/com/example/servingwebcontent/GreetingController.java[]

This controller is concise and simple, but there is plenty going on. We break it down step by step.

The @GetMapping annotation ensures that HTTP GET requests to /greeting are mapped to the greeting() method.

@RequestParam binds the value of the query string parameter name into the name parameter of the greeting() method. This query string parameter is not required. If it is absent in the request, the defaultValue of World is used. The value of the name parameter is added to a Model object, ultimately making it accessible to the view template.

The implementation of the method body relies on a view technology (in this case, Thymeleaf) to perform server-side rendering of the HTML. Thymeleaf parses the greeting.html template and evaluates the th:text expression to render the value of the ${name} parameter that was set in the controller.The following listing (from src/main/resources/templates/greeting.html) shows the greeting.html template:

link:complete/src/main/resources/templates/greeting.html[]
Tip
Make sure you have Thymeleaf on your classpath (artifact co-ordinates: org.springframework.boot:spring-boot-starter-thymeleaf). It is already there in the "initial" and "complete" samples in Github.

Spring Boot Devtools

A common feature of developing web applications is coding a change, restarting your application, and refreshing the browser to view the change. This entire process can eat up a lot of time. To speed up this refresh cycle, Spring Boot offers with a handy module known as spring-boot-devtools. Spring Boot Devtools:

  • Enables hot swapping.

  • Switches template engines to disable caching.

  • Enables LiveReload to automatically refresh the browser.

  • Other reasonable defaults based on development instead of production.

Run the Application

The Spring Initializr creates an application class for you. In this case, you need not further modify the class provided by the Spring Initializr. The following listing (from src/main/java/com/example/servingwebcontent/ServingWebContentApplication.java) shows the application class:

link:complete/src/main/java/com/example/servingwebcontent/ServingWebContentApplication.java[]

Logging output is displayed. The application should be up and running within a few seconds.

Test the Application

Now that the web site is running, visit http://localhost:8080/greeting, where you should see “Hello, World!”

Provide a name query string parameter by visiting http://localhost:8080/greeting?name=User. Notice how the message changes from “Hello, World!” to “Hello, User!”:

This change demonstrates that the @RequestParam arrangement in GreetingController is working as expected. The name parameter has been given a default value of World, but it can be explicitly overridden through the query string.

Add a Home Page

Static resources, including HTML and JavaScript and CSS, can be served from your Spring Boot application by dropping them into the right place in the source code. By default, Spring Boot serves static content from resources in the classpath at /static (or /public). The index.html resource is special because, if it exists, it is used as a "`welcome page,"serving-web-content/ which means it is served up as the root resource (that is, at `http://localhost:8080/). As a result, you need to create the following file (which you can find in src/main/resources/static/index.html):

link:complete/src/main/resources/static/index.html[]

When you restart the application, you will see the HTML at http://localhost:8080/.

Summary

Congratulations! You have just developed a web page by using Spring.

You can’t perform that action at this time.