Try Hello World with the minimum configuration of Heroku Java spring-boot

Overview

Let's create an environment where Hello World can be done with the fastest / minimum configuration for launching a new Web service with Heroku + Java + spring-boot

To be able to

• Hello World on Heroku

Approximate working time

Half an hour

What you need in advance

• Java
• Maven
• git
• Heroku account

Heroku account is described in the following article 1. You only need to get Heroku Account in Introduction You can get it immediately for free (email address only. No credit card registration required) I tried Heroku, which can publish web applications for free

1. 1. Create spring-boot environment

There are two files to prepare, pom.xml and HelloController.java.

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns="http://maven.apache.org/POM/4.0.0"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>sprin-boot-sample</groupId>
  <artifactId>sprin-boot-sample</artifactId>
  <version>1.0</version>
  <packaging>jar</packaging>

  <name>sprin-boot-sample</name>

  <properties>
    <java.version>1.8</java.version>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
  </properties>

  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.9.RELEASE</version>
  </parent>

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

  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
        <executions>
          <execution>
            <goals>
              <goal>build-info</goal>
            </goals>
            <configuration>
              <additionalProperties>
                <encoding.source>${project.build.sourceEncoding}</encoding.source>
                <encoding.reporting>${project.reporting.outputEncoding}</encoding.reporting>
                <java.source>${maven.compiler.source}</java.source>
                <java.target>${maven.compiler.target}</java.target>
              </additionalProperties>
            </configuration>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
</project>

HelloController.java

package com.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
@EnableAutoConfiguration
public class HelloController {

    @RequestMapping("/")
    @ResponseBody
    public String home() {
        return "Hello, World!";
    }

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

}

2. Prepare a configuration file for your Heroku environment

Three files are required. 　Procfile／system.properties／application.properties

Procfile

web: java -jar target/sprin-boot-sample-1.0.jar

system.properties

java.runtime.version=1.8

application.properties

server.port=${PORT:5000}

3. 3. Prepare .gitignore so you don't upload unnecessary files to Heroku

.gitignore

target

The final composition looks like the following

{folder}
│  .gitignore
│  pom.xml
│  Procfile
│  system.properties
│      
└─src
    └─main
        ├─java
        │  └─com
        │      └─example
        │              HelloController.java
        │              
        └─resources
                application.properties

4. Commit to local git repository

git init
git add .
git commit -m "first commit"

5. Deploy to Heroku

heroku login
heroku create
git push heroku master
heroku open

6. Screen check

that's all.

Impressions

If you have a Heroku account, you can create a web service template in 30 minutes. It has only spring-boot configuration, but is it more convenient if other FWs are added to the template?