This project is created for training Java knowledge. It will consist of two modules - backend an UI.

JDK11 or later

Client: Java, Swing, HttpClient, DTO

Server: Java, Spring Boot, Spring Data JPA, Flyway Migration, Postgresql

• Chat rooms
• Contact list
• Message history

Create an Application User and group

  sudo groupadd -r messenger_group
  sudo useradd -r -s /bin/false -g messenger_group messenger_user

Create Systemd Service First, create a systemd service file to manage our application

sudo vim /etc/systemd/system/backend.service

It will have content like below:

[Unit]
Description=Simple messenger backend service

[Service]
WorkingDirectory=/opt/messenger
ExecStart=/bin/java -Xms128m -Xmx256m -jar -Dspring.profiles.active=dev backend-0.1.1-SNAPSHOT.jar
User=messenger_user
Type=simple
Restart=on-failure
RestartSec=10

[Install]
WantedBy=multi-user.target

Set User to the one created earlier, and WorkingDirectory to the directory with a jar file.

Give the user and group ownership permissions for the Project Directory:

sudo chown -R messenger_user:messenger_group /opt/messenger

reload systemd so that it knows of the new application added.

sudo systemctl daemon-reload

Start Java Application service with systemd

  sudo systemctl start backend.service

To check the status, use:

  systemctl status backend

You can also enable the service to start on server boot:

  sudo systemctl enable backend

To restart the application, use:

  sudo systemctl restart backend

I'm a Java developer... https://github.com/vosmerkin

• Create UI
• Create backend basic application
• Add user login / logoff functionality
• Add chat rooms
• Test deploy
• Add messages functionality
• Add message history