[Spring Boot] Traditional Deployment on Apache Tomcat using Spring Boot WAR
This article covers how to create a Spring Boot application which can output a war file and how to deploy on Apache Tomcat.
This application is based on Spring Boot version 3 & Java 17 with Apache Tomcat 10. Apache Tomcat 10 can be downloaded from here.
Project Setup
Note that gradle war creates a WAR file which cannot be executed stand alone where as gradle bootWar creates an executable WAR.
plugins {
java
war
id("org.springframework.boot") version "3.1.2"
id("io.spring.dependency-management") version "1.1.2"
}
group = "io.jay"
version = "0.0.1-SNAPSHOT"
apply(plugin = "war")
java {
sourceCompatibility = JavaVersion.VERSION_17
}
repositories {
mavenCentral()
}
dependencies {
implementation("org.springframework.boot:spring-boot-starter-web")
providedRuntime("org.springframework.boot:spring-boot-starter-tomcat")
testImplementation("org.springframework.boot:spring-boot-starter-test")
}
tasks.withType<Test> {
useJUnitPlatform()
}
tasks.war {
archiveFileName.set("service.war")
}Implementation
Note that the main class has to extend SpringBootServletInitializer and configure() is overridden.
package io.jay.service;
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;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.ResponseBody;
@SpringBootApplication
public class MainApplication extends SpringBootServletInitializer {
@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
return application.sources(MainApplication.class);
}
public static void main(String[] args) {
SpringApplication.run(MainApplication.class, args);
}
}
@Controller
class TomcatController {
@GetMapping("/")
public String index() {
return "index.html";
}
}
@Controller
@ResponseBody
class HelloController {
@GetMapping("/hello")
public String hello() {
return "Hello there !";
}
}Let us create index file for fun.index.html is placed under src/main/resources/static:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html;charset=UTF-8">
<title>Document</title>
</head>
<body>
<h1>Hello</h1>
</body>
</html>Building and Deploying
Let us build a WAR file using gradle war command. This will output service.war where service is the name of this application. I downloaded and extracted Tomcat under ~/Downloads/apache-tomcat-10.1.11. This will be my Tomcat path.
Copy the WAR file and place under ~/Downloads/apache-tomcat-10.1.11/webapps.
When I first downloaded and extracted Tomcat, all the executable files did not have permission to be executed.
cd ~/Downloads/apache-tomcat-10.1.11
# to start up Tomcat
chmod +x bin/catalina.sh
chmod +x bin/startup.sh
# to shut down Tomcat
chmod +x bin/shutdown.shStart Tomcat by running ~/Downloads/apache-tomcat-10.1.11/bin/startup.sh script.
There will be a service directory once Tomcat is started.
The Spring Boot application will be served under http://localhost:8080/service.
