package database;

import org.junit.Test;

import java.io.IOException;
import java.sql.*;

public class Main {

    private final static String URL ="jdbc:mysql://localhost:3306/catalog?useSSL=false";
    private final static String USERNAME = "root";
    private final static String PASSWORD = "root";+
    private final static String FILEPATH = "./src/main/resources/input.txt";

    public static void main(String[] args) throws SQLException, IOException {
      Reader reader = new Reader(FILEPATH);
      StudentParser parser = new StudentParser();
      DatabaseWriter dbWriter = new DatabaseWriter(URL, USERNAME, PASSWORD);

   try {
        while (reader.hasNext()==true){
            String line = reader.next();
            Student student = parser.parse(line);
            dbWriter.writeStudent(student);
            }
        }
        catch (NullPointerException e){
        e.printStackTrace();
        }finally {
            dbWriter.close();
            reader.close();
        }
    }
}
package database;

import org.junit.jupiter.api.Test;

import java.util.LinkedList;

public class StudentParser {

    public Student parse(String line){
        String [] words = line.split(",");
        Student student = null;
        int lenght = words.length;

        if(lenght == 1){
            student = new Student(words[0]," "," ");
        }
        else
        if (lenght == 2) {
          student = new Student(words[0], words[1], " ");

        } else
        if(lenght == 3) {
            student = new Student(words[0], words[1], words[2]);
        }
        return student;
    }
}
package database;

import java.io.Closeable;
import java.io.IOException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class DatabaseWriter implements Closeable {
    private final static String INSERT = "INSERT INTO students VALUES(?,?,?,?)";
    private String URL,USERNAME,PASSWORD;
    int count = 1;
    DatabaseWriter(String URL,String USERNAME,String PASSWORD) throws SQLException {
        this.URL = URL;
        this.USERNAME = USERNAME;
        this.PASSWORD = PASSWORD;
        DBConnector dbc = new DBConnector();
        Connection conn = dbc.getConnection(URL,USERNAME,PASSWORD);
        PreparedStatement preparedStatement = conn.prepareStatement(INSERT);
    }

    public void writeStudent(Student student) throws SQLException {
        PreparedStatement preparedStatement = conn.prepareStatement(INSERT);
        preparedStatement.setInt(1, count);
        preparedStatement.setString(2, student.getFirstName());
        preparedStatement.setString(3, student.getLastName());
        preparedStatement.setString(4, student.getAge());
        preparedStatement.execute();
        count++;
    }

    @Override
    public void close() throws IOException {
        conn.close();
    }
}
package database;

import com.mysql.fabric.jdbc.FabricMySQLDriver;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DBConnector {
    private Connection connection;
    public DBConnector() throws SQLException{
        DriverManager.registerDriver(new FabricMySQLDriver());
    }

    public Connection getConnection(String url, String username, String password) throws SQLException{
        if(connection != null)
            return connection;
        connection = DriverManager.getConnection(url, username, password);
        return connection;
    }
}
package database;

public class Student {
    private   String firstName,lastName,age;

    Student(String name,String surname,String StudentAge){
        firstName = name;
        lastName = surname;
        age = StudentAge;
    }

    public String toString(){
        return this.firstName + " " + this.lastName + " " + this.age;
    }
    public String getFirstName(){
        return firstName;
    }

    public String getLastName(){
        return lastName;
    }

    public String getAge(){
        return age;
    }
}