In this tutorial, I show you how we can deploy a Spring Boot application using JSP to external Tomcat server. First we create a simple Spring boot web application with JSP then we will create a WAR file of it and finally we deploy the WAR file in the external tomcat server.

Learn Spring boot at https://www.javaguides.net/p/spring-boot-tutorial.html.

Learn Hibernate at https://www.javaguides.net/p/hibernate-tutorial.html

Development Steps

Create Spring Boot Application
Add maven dependencies
Configure InternalResourceViewResolver for JSPs in application.properties file
Create JSP page
Create WAR file
Deploy to Tomcat

1. Create a Spring Boot Application

There are many ways to create a Spring Boot application. You can refer below articles to create a Spring Boot application.

>> Create Spring Boot Project With Spring Initializer
>> Create Spring Boot Project in Spring Tool Suite [STS]

2. Add maven dependencies

<?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>2.1.0.RELEASE</version>
        <relativePath />
        <!-- lookup parent from repository -->
    </parent>
    <groupId>net.javaguides</groupId>
    <artifactId>spring-data-war</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>
    <name>spring-data-war</name>
    <description>Demo project for Spring Boot Restful web services</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- Need this to compile JSP -->
        <dependency>
            <groupId>org.apache.tomcat.embed</groupId>
            <artifactId>tomcat-embed-jasper</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>
    <build>
        <finalName>springboot-jsp-web</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

3. Create HelloWorldController

Let's create a simple HelloWorldController class which exposes a "/test" request mapping:

package net.javaguides.springboot;

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

@Controller
public class HelloWorldController {
    @RequestMapping("/test")
    public String sayHello() {
        return "hello";
    }
}

3. Configure InternalResourceViewResolver for JSPs in application.properties file

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

4. Create JSP page

Create JSP view pages under src/main/webapp/WEB-INF/view directory ( If the directory does not exist then create directory structure):

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
    <p>
    Hello World! Time is <%= new java.util.Date() %>
    </p>
     
    <p>
    We are running on  <%= application.getServerInfo() %>!!!
    </p>
    
</body>
</html>

5. Create WAR file

To create a WAR file, perform the following steps.

1. Update main Spring Boot application

In your main Spring Boot application, you need to extend the SpringBootServletInitializer and override the configure(...) method:

package net.javaguides.springboot;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;

@SpringBootApplication
public class SpringDataWarApplication extends SpringBootServletInitializer {

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

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

3. Update Maven POM file

Update your POM.xml to use WAR packaging

<packaging>war</packaging>

In POM.xml, add dependency to be able to compile JSPs

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

Make sure the Tomcat embedded does not interfere with the external Tomcat server.

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

Create the WAR file with the command:

mvn clean install

This will generate a WAR file in your project directory: target/springboot-jsp-web.war

6. Deploy to Tomcat

Copy your WAR file to the <tomcat-server>/webapps directory, wait for few seconds for Tomcat to deploy your app.

In a web browser, access your app at: http://localhost:8080/springboot-jsp-web/test

If everything is successful, you will see your application's web page.

Congratulations! You deployed a Spring Boot WAR file with JSP on to a Tomcat server.