iloveyii / hotel_backend

A Java Spring Boot backend API application, Dockerized, Test, MVC

JAVA Spring boot

Spring boot based web application

Installations

Installations

Windows

• Download IntelliJ
• Download Docker Desktop
• Download Git Desktop
  • You need to enable hyper-v/virtualization in your computer bios OR vmware player settings > hardware > processor > virtualization engine.
  • If memory problem, then infact decreasing it from 4GB to something lower will work
• Download WSL2 update

Ubuntu

Java

• Install update sudo apt update
• Install jdk sudo apt install openjdk-11-jdk
• Install jre sudo apt install openjdk-11-jre
• Some applications still don’t fully support the latest OpenJDK 11. For those, they can install the previous Java LTS which was version 8.
• sudo apt install openjdk-8-jdk
• If you have multiple versions of Java installed, simply use the commands below to set which one should be the default for your system.
• sudo update-alternatives --config java
• Some programs require that JAVA_HOME is configured on the system. You can set the default home by using the lines above in the config file.
• For Java 11, it displays /usr/lib/jvm/java-11-openjdk-amd64 and Java 8, it’s /usr/lib/jvm/java-8-openjdk-amd64.
• To set their homes, run the commands below to open the system environment file.
• sudo nano /etc/environment
• Then add a line for Java 11 as below:
• JAVA_HOME="/usr/lib/jvm/java-11-openjdk-amd64"
• Run the commands below to save your changes.
• source /etc/environment

Maven

• Install maven sudo apt update && sudo apt install maven

Spring

• Install plugin in Settings > Plugins and search Spring Assistant
• Create spring based app in IJ and add dependencies, web, devtools, actuator
• Create Controller at src main java with annotations like Controller, GetMapping etc
• Open src main java @SpringBootApplication, at the right of class click the green Run button ( CTRL + SHIFT + F10)

Configuration

• The view paths in templates/application.properties

    spring.mvc.view.prefix: /WEB-INF/
    spring.mvc.view.suffix: .html

Testing

• Click inside controller method and click generate from menu or alt+insert
• Add a test :
  • Arrange: create controller object
  • Act : Run the test
  • Assert: Compare results

Deploy

• Build jar mvn clean install
• Find jar file in target dir and run java -jar file.jar
• Run with pm2 pm2 start 'java -jar file.jar' --name java-tomcat

Run with Docker

• Build docker build -t hotel_backend_image .
• Run docker run -ti --rm -v /home/alex/projects/java/hotel_backend/:/java/app/ -p 8090:8090 --name hotel_backend_container hotel_backend_image bash
• Make jar mvn clean install
• Run jar file java -jar target/backend-0.0.1-SNAPSHOT.jar

Run with Docker Compose

• Build docker-compose up --build

Shortcuts IntelliJ

• Insert dependency -> open pom file -> ALT + Insert

Issues

• Could not initialize class org.jetbrains.jps.builders.JpsBuildBundle
• Solution: Update / reinstall IJ