Is this good sql class?

package com.gmail.JyckoSianjaya.DonateCraft.Database;

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

import org.bukkit.Bukkit;
import org.bukkit.scheduler.BukkitRunnable;

import com.gmail.JyckoSianjaya.DonateCraft.Main.DonateCraft;
import com.gmail.JyckoSianjaya.DonateCraft.Utils.Utility;

public class SimpleSQL {
    private static SimpleSQL instance;
    private Connection connection;
    private String hostname = ""; // The host name
    private int port = 0; // The host port
    private String databasename = ""; // The name of the database
    private String username = ""; // MySQL username
    private String password = ""; // MySQL password
    private SimpleSQL(String hostname, int port , String databasename, String username, String password) {
        this.hostname = hostname;
        this.port = port;
        this.databasename = databasename;
        this.username = username;
        this.password = password;
        new BukkitRunnable() {
            Boolean loaded = false;
            @Override
            public void run() {
                Bukkit.getServer().broadcastMessage("Praya gantengus megantrophus paleojavanicus");
                if (!loaded) {
                    try {
                        openConnection();
                        Statement state = connection.createStatement();
                    } catch (SQLException e) {
                        Utility.sendConsole("[DC] &7Can't open a MySQL connection, is it correct?");
                    } catch (ClassNotFoundException e) {
                        Utility.sendConsole("[DC] &7Can't find SQL class. Please contact the author via spigot conversation.");
                    }
                }
                Boolean closed = false;
                try {
                    closed = connection.isClosed();
                } catch (SQLException e) {
                    Utility.sendConsole("[DC] &7Can't check if Connection closed. Is it okay?");
                }
                if (closed) {
                    try {
                        openConnection();
                        Statement state = connection.createStatement();
                    } catch (SQLException e) {
                        Utility.sendConsole("[DC] &7Can't open a MySQL connection, is it correct?");
                    } catch (ClassNotFoundException e) {
                        Utility.sendConsole("[DC] &7Can't find SQL class. Please contact the author via spigot conversation.");
                    }
                }
            }
        }.runTaskTimerAsynchronously(DonateCraft.getInstance(), 100L, 100L);
    }
    public static SimpleSQL setup(String host, int port, String database, String user, String pass) {
        if (instance != null) return null;
        instance = new SimpleSQL(host, port, database, user, pass);
        return instance;
    }
    public void openConnection() throws SQLException, ClassNotFoundException {
        if (connection != null && !connection.isClosed()) {
            return;
        }

        synchronized (this) {
            if (connection != null && !connection.isClosed()) {
                return;
            }
            Class.forName("com.mysql.jdbc.Driver");
            connection = DriverManager.getConnection("jdbc:mysql://" + this.hostname+ ":" + this.port + "/" + this.databasename, this.username, this.password);
        }
    }
}