Spring Boot Hello World - JSP tutorial

Tutorial describing how to create the simple Hello World application using Spring Boot and JSP.

Technologies used:

Spring Boot 2.1.7.RELEASE
JDK 1.8
Maven 3
JSP

Project setup

Project dependencies managed by the Maven’s pom.xml configuration file:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.7.RELEASE</version>
        <relativePath/>
    </parent>
    
    <groupId>com.devcases.springboot</groupId>
    <artifactId>springboot-helloworld-jsp</artifactId>
    <version>1.0.0-SNAPSHOT</version>
    <packaging>war</packaging>

    <properties>
        <java.version>1.8</java.version>
    </properties>

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>

        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
            <scope>provided</scope>
        </dependency>
    </dependencies>

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

</project>

The explanation of the above dependencies:

spring-boot-starter-web – packages all the necessary dependencies together with the auto configuration for running simple web application
spring-boot-starter-tomcat – provides the embedded tomcat application server
tomcat-embed-jasper – enables support for JSP
spring-boot-maven-plugin – plugin prividing commands to work with a Spring Boot application (we will be usine the spring-boot:run command)

Application Initializer

The standard spring boot application initializer, which our application need to provide:

@SpringBootApplication
public class Application extends SpringBootServletInitializer {

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(Application.class);
    }

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

Controller

The controller containing rest services:

@Controller
public class HelloWorldController {

    private static final String message = "Hello World";

    @GetMapping(value = "/")
    public String hello(Map<String, Object> model) {
        model.put("message", message);
        return "hello";
    }
}

The controller has only one endpoint available at the root address (/ – in our example it is resolved to the localhost:8080) . The method passes the message parameter to the hello view.

View

<!DOCTYPE html>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags"%>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>${message}!</title>
</head>
<body>
    <h2>${message}!</h2>
</body>
</html>

The view contains a simple html page, that shows passed parameter.

Configuration

The configuration in application.properties file contains information how to resolve JSP files.

spring.mvc.view.prefix: /WEB-INF/jsp/
spring.mvc.view.suffix: .jsp

Running

The project can be started by the running the following command:

mvn clean spring-boot:run

The command deploys the apllication on the embedded tomcat server.

By visiting the localhost:8080 url, we should see the page containg the Hello World message.

The example code you can download from here