Java beginner tried to make a simple web application using Spring Boot

Introduction

――For various reasons, I am studying Spring Boot. ――I don't remember Java itself, Servlets, JSPs, etc. too long ago. So it will be a beginner start. ――I was able to make a simple SPA in about 16 hours in total, while fitting it securely in each step. ――There is no special design.

Execution environment

Development environment

Application environment

Various installations from Homebrew

Update brew

brew update && brew upgrade && brew cleanup

Java

Installation

brew cask install java

PATH setting

export JAVA_HOME=`/usr/libexec/java_home -v 1.8`

Tomcat

Installation

brew install tomcat

Gradle

Installation

brew install gradle

Eclipse installation

Download Mars

https://www.eclipse.org/downloads/packages/release/Mars/2

• Select Eclipse IDE for Java EE Developers.

Installation

Place Eclipse.app under / Applications.

Download various plug-ins

** Japanese localization plug-in ** http://mergedoc.osdn.jp/#pleiades.html

• Please download from the Pleiades plug-in download at the bottom of the page.

JStyle http://mergedoc.osdn.jp/#jstyle.html

Localizing into Japanese

Place the jp.sourceforge.mergedoc.pleiades directory of the unzipped plugin under /Applications/Eclipse.app/Contents/Eclipse/plugins/.

Open /Applications/Eclipse.app/Contents/Eclipse/eclipse.ini and add the writing.

-Xverify:none
-javaagent:/Applications/Eclipse.app/Contents/Eclipse/plugins/jp.sourceforge.mergedoc.pleiades/pleiades.jar

JStyle

Place the unzipped plugin jar under /Applications/Eclipse.app/Contents/Eclipse/plugins/.

Initial setup of Eclipse

After starting, open the environment settings at the top left of the screen.

--From "Java> Compiler", change the Java version to 1.8. --Add Java SE 8 from "Java> Installed JRE". --Adjust the "General> JStyle" settings. --Set "General> Web Browser". --If proxy settings are required, set "General> Network Connection".

Tomcat connection settings

After startup, open "Server> Runtime Environment" from the environment settings at the top left of the screen.

1. Select "Apache> Apache Tomcat v8.0" from Add and proceed.
2. Enter the name and Tomcat installation directory. The directory is as follows.

/usr/local/Cellar/[email protected]/8.0.43/libexec

Install Spring and Gradle plugins

STS installation

1. Open Help> Eclipse Marketplace at the top of the screen.
2. Enter STS in the search window to install.

Install Gradle plugin

1. Open Help> Eclipse Marketplace at the top of the screen.
2. Enter Gradle in the search window to install.

Creating a Spring Boot project

1. Open "File> New> Create Spring Starter Project" at the top of the screen.
2. Enter the project name and check the box below to complete.

Tomcat startup port and database connection settings

-Edit /projectname/src/main/resources/application.properties.

//Tomcat startup port
server.port=18080

//Database connection settings
spring.datasource.url=jdbc:mysql://localhost:3306/{Database name}
spring.datasource.username=root
spring.datasource.password=
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

Creating an application

――This time, I created the following functions.

--Users have attributes such as groups to form a join relationship.

Creating databases and tables

CREATE DATABASE {Database name} DEFAULT CHARACTER SET utf8;

CREATE TABLE `groups` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(20) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;

CREATE TABLE `users` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `group_id` int(11) NOT NULL,
  `name` varchar(20) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;

Input of initial data

INSERT INTO `groups` VALUES (1,'admin'),(2,'sales');
INSERT INTO `users` VALUES (1,1,'Tanaka'),(2,2,'Takahashi'),(3,2,'Suzuki');

Implementation

--I learned from Domain Driven (DDD) and constructed the class, but please understand that it may contain some code that is not so good. --The actual source code.

Source code

https://github.com/neriai/spring-boot-sandbox

Run

Run application

Select the project, right-click and click Run> Spring Boot Application.

demo

Summary

――It was more likely to fit in JPA, Thymeleaf or other libraries than in Java or Spring Boot. --Gradle Easy to use. --The area around Entity fits. --It is recommended to set it as a shortcut for running or stopping the application in Eclipse.