Java tips-Create a Spring Boot project in Gradle

Create a Spring Boot project in Gradle

Nowadays, you can create a Spring Boot project with just one click such as eclipse. But how do you create a Spring Boot project without the help of eclipse? I would like to write up to the point where RestController returns HelloWorld based on memorandum. (It's not that I don't use eclipse.)

environment

I have installed and running the following on my Mac.

• Gradle 5.5.1
• JDK openjdk64-11.0.4
• eclipse 201906

table of contents

1. Create Gradle project
2. eclipse import
3. Spring Boot dependency arrangement
4. Java class creation
5. Create Jar

this section

1. Create Gradle project

First, create an empty directory and create a Gradle project.

#Create an empty directory
mkdir GradleSpringBoot

#Gradle project
cd GradleSpringBoot
gradle init

#After typing the init command, the following options will appear, so select the one that applies.
#This time, we will select it to be a Java project.
Select type of project to generate:
  1: basic
  2: application
  3: library
  4: Gradle plugin
Enter selection (default: basic) [1..4] 2

Select implementation language:
  1: C++
  2: Groovy
  3: Java
  4: Kotlin
Enter selection (default: Java) [1..4] 3

Select build script DSL:
  1: Groovy
  2: Kotlin
Enter selection (default: Groovy) [1..2] 1

Select test framework:
  1: JUnit 4
  2: TestNG
  3: Spock
  4: JUnit Jupiter #It's JUnit 5. If you don't have a reason, choose JUnit 5 as it's new.
Enter selection (default: JUnit 4) [1..4] 4

2. eclipse import

Rewrite build.gradle so that you can import your Gradle project into eclipse.

    id 'application'
//Let's add the following plugin around the 15th line.
    id 'eclipse'

After editing and saving, let's execute the following command.

#"Necessary to recognize as an eclipse project".project」「.Create a "setting".
gradle eclipse

At this point, you can import it into eclipse, so Let's import with import-> existing projects into workspace.

3. Spring Boot dependency arrangement

The dependency of SpringBoot is summarized by Gradle official site, so please refer to this for build. Edit .grale.

build.gradle

/*
 * This file was generated by the Gradle 'init' task.
 *
 * This generated file contains a sample Java project to get you started.
 * For more details take a look at the Java Quickstart chapter in the Gradle
 * User Manual available at https://docs.gradle.org/5.5.1/userguide/tutorial_java_projects.html
 */

plugins {
    // Apply the java plugin to add support for Java
    id 'java'

    // Apply the application plugin to add support for building a CLI application
    id 'application'
    id 'eclipse'
    id 'com.gradle.build-scan' version '2.3'
    id 'org.springframework.boot' version '2.1.6.RELEASE'
    id 'io.spring.dependency-management' version '1.0.8.RELEASE'
}

repositories {
    // Use jcenter for resolving dependencies.
    // You can declare any Maven/Ivy/file repository here.
    jcenter()
}

dependencies {
    // This dependency is used by the application.
    implementation 'com.google.guava:guava:27.1-jre'
    
    implementation 'org.springframework.boot:spring-boot-dependencies:2.1.6.RELEASE'
    implementation 'org.springframework.boot:spring-boot-starter-web:2.1.6.RELEASE'

	// https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-test
	testImplementation 'org.springframework.boot:spring-boot-starter-test:2.1.6.RELEASE'

    // Use JUnit Jupiter API for testing.
    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.4.2'

    // Use JUnit Jupiter Engine for testing.
    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.4.2'
    
    components {
        withModule('org.springframework:spring-beans') {
            allVariants {
                withDependencyConstraints {
                    // Need to patch constraints because snakeyaml is an optional dependency
                    it.findAll { it.name == 'snakeyaml' }.each { it.version { strictly '1.19' } }
                }
            }
        }
    }
}

bootJar {
    mainClassName = 'co.jp.study.App'
}

buildScan {

    // always accept the terms of service
    termsOfServiceUrl = 'https://gradle.com/terms-of-service'
    termsOfServiceAgree = 'yes'

    // always publish a build scan
    publishAlways()
}

test {
    // Use junit platform for unit tests
    useJUnitPlatform()
}

The version of each library is set to the latest one (as of July 26, 2019) while checking with maven.

4. Java class creation

We will create a POJO class to start SpringBoot and a RestController to return HelloWorld.

App.java

package co.jp.study;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

/**
 *SpringBoot boot class
 */
@SpringBootApplication
public class App {
	public static void main(String[] args) {
		SpringApplication.run(App.class, args);
	}
}

HelloController

package co.jp.study.controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

/**
 *Sample RestController class
 */
@RestController("/")
public class HelloContoller {

	@RequestMapping
	public String hello() {
		return "Hello World!";
	}

}

5. Create Jar

Execute the following command on the console Create siteiki and Jar and start Spring Boot.

#Creating a jar
gradle bootJar
#Run
gradle bootRun

If you access the following address and output "Hello World", it is successful. http://localhost:8080/

Summary

Thank you for your hard work. Thank you for reading the long text. Let's send a comfortable Spring Boot development.