#database
spring.jpa.hibernate.ddl-auto=validate
spring.datasource.url=jdbc:mysql://localhost:3306/notification?true&useSSL=false
spring.datasource.username=root
spring.datasource.password=root

package notification.controllers;

import notification.entities.Command;
import notification.repo.CommandRepository;
import notification.services.NotificationService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.jpa.repository.Modifying;
import org.springframework.stereotype.Controller;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;

import java.text.ParseException;
import java.util.Map;

@Controller
public class NotificationController
{
    @Autowired
    private CommandRepository commandRepository;

    @Autowired
    private NotificationService notificationService;

    @GetMapping("/")
    public String command(Map<String,Object> model)
    {
        Iterable<Command> commands = commandRepository.findAll();

        model.put("commands", commands);
        return "command";
    }

    @Transactional
    @Modifying
    @PostMapping
    public String add(@RequestParam String name,
                      @RequestParam String message,
                      @RequestParam String time,
                      @RequestParam String notificationType,
                      @RequestParam String extra_params,
                      Map<String, Object> model) throws ParseException {
        Command command = new Command(name, message, time, notificationType, extra_params);

        commandRepository.save(command);

        Iterable<Command> commands = commandRepository.findAll();

        model.put("commands", commands);
        notificationService.sendNotification(command);

        return "command";
    }
}

package notification.entities;

import javax.persistence.*;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

@Entity
@Table(name = "command")
public class Command {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @Column(name = "name")
    private String name;

    @Column(name = "message")
    private String message;

    @Column(name = "time")
    private Date time;

    @Column(name = "notificationType")
    @Enumerated(EnumType.STRING)
    private NotificationType notificationType;

    @Column(name = "extra_params")
    private String extra_params;

    public Command() {
    }

    public Command(String name, String message, Date time, NotificationType notificationType, String extra_params) {
        this.name = name;
        this.message = message;
        this.time = time;
        this.notificationType = notificationType;

        try {
            if (notificationType == NotificationType.email)
                this.extra_params = extra_params.substring(6);
            else
                this.extra_params = extra_params.substring(4);
        } catch (StringIndexOutOfBoundsException e) {
            //The field has to be email= or url=
        }

        try {
            if (!Command.checkParams(notificationType, extra_params)) {
                this.extra_params = "";
                throw new IllegalArgumentException();
            }
        } catch (IllegalArgumentException e) {
            System.err.println("notification type and extra param don't coincide");
        }


    }

    public Command(String name, String message, String time, String notificationType, String extra_params) throws ParseException {
        this(name, message, Command.getCorrect(time), NotificationType.fromString(notificationType), extra_params);
    }

    public static Date getCorrect(String time) throws ParseException {
        DateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm");
        Date date;
        date = format.parse(time);
        return date;
    }

    public static String getCorrect(Date time) {
        String date = new SimpleDateFormat("yyyy-MM-dd HH:mm").format(time);

        return date;
    }

    public static boolean checkParams(NotificationType nt, String extraParam) {
        boolean right = true;
        try {
            if (nt == NotificationType.http) {
                right = extraParam.indexOf("url=http://") == 0;
            } else if (nt == NotificationType.email) {
                right = extraParam.indexOf("email=") == 0;
                right &= extraParam.indexOf('@') == extraParam.lastIndexOf('@');
                right = right & ((extraParam.indexOf(".ru") == extraParam.length() - 3) || (extraParam.indexOf(".com") == extraParam.length() - 4));
            }
        } catch (NullPointerException e) {
            //The field can't be empty
        }
        return right;
    }

    public String getExtra_params() {
        return extra_params;
    }

    public void setExtra_params(String extra_params) {
        this.extra_params = extra_params;
    }

    public NotificationType getNotificationType() {
        return notificationType;
    }

    public void setNotificationType(NotificationType notificationType) {
        this.notificationType = notificationType;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public Date getTime() {
        return time;
    }

    public void setTime(Date time) {
        this.time = time;
    }

    @Override
    public String toString() {
        return "message ==  " + message +
                "; time == " + time +
                "; type == " + notificationType +
                "; params == " + extra_params;
    }
}

import notification.entities.Command;
import org.springframework.data.repository.CrudRepository;

public interface CommandRepository extends CrudRepository<Command, Long>
{
}