Deploy a Spring Boot WAR to an Tomcat Server - Hello World Example

In this example we will learn how to to deploy a Spring Boot Application as a WAR to an external tomcat. So we will not be using the embedded tomcat using which we used to deploy the Spring Boot Application as a JAR.

Lets Begin-

In a previous tutorial we had created a simple Spring Boot Web Application named employee-producer, that exposed a REST web service. This was developed to be deployed using JAR packaging.
We will quickly modify this Application to be deployed using WAR packaging. The project we will as follows-

In the pom.xml change the packaging to WAR.

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<groupId>com.javainuse</groupId>
	<artifactId>employee-producer</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>war</packaging>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.4.1.RELEASE</version>
		<relativePath /> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<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-test</artifactId>
			<scope>test</scope>
		</dependency>

	</dependencies>

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


</project>

Next modify the Spring BootStrap class which extends the SpringBootServletInitializer class to initialize the Servlet context required by Tomcat.

package com.javainuse;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.support.SpringBootServletInitializer;
 
@SpringBootApplication
public class SpringBootHelloWorldApplication  extends SpringBootServletInitializer {
	
	@Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(SpringBootHelloWorldApplication.class);
    }
 
	public static void main(String[] args) {
		SpringApplication.run(SpringBootHelloWorldApplication.class, args);
	}
}

Run maven command - clean install, and a war file gets created in the target folder.

Download Source Code

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Spring Boot WAR Deployment