StorageLib.java

import java.sql.*;

public class StorageLib {


    /**
     * Der MySQL-Host, z.B. 'localhost' oder 'vweb02.nitrado.net'
     */
    private static final String MYSQL_HOST = "localhost";

    /**
     * Der MySQL-Benutzer, z.B. 'root' oder 'ni12345_1sql1'
     */
    private static final String MYSQL_USER = "root";

    /**
     * Das MySQL-Passwort
     */
    private static final String MYSQL_PASSWORD = "123";

    /**
     * Der Name der MySQL-Datebank, z.B. 'db' oder 'ni12345_1sql1'
     */
    private static final String MYSQL_DATABASE = "db";

    /**
     * Der Name der MySQL-Tabelle, z.B. 'money'
     */
    private static final String MYSQL_TABLE = "money";

    /**
     * Die Spalte, in der die Spieler-Namen gespeichert werden
     */
    private static final String USER_COLUMN = "Player";

    /**
     * Die Spalte, in der die Zahlen gespeichert werden
     */
    private static final String INT_COLUMN = "Zahl";


    private static Connection connection;

    public static void load() {
        try {
            Class.forName("com.mysql.jdbc.Driver");
        } catch (ClassNotFoundException ex) {
            ex.printStackTrace();
        }

        try {
            connection = DriverManager.getConnection("jdbc:mysql://" + MYSQL_HOST + "/" + MYSQL_DATABASE, MYSQL_USER, MYSQL_PASSWORD);
        } catch (SQLException ex) {
            ex.printStackTrace();
        }
    }

    public static void set(String playerName, int number) {
        try {
            PreparedStatement checkStatement = connection.prepareStatement("SELECT ? FROM ? WHERE ? = ?;");
            checkStatement.setString(1, INT_COLUMN);
            checkStatement.setString(2, MYSQL_TABLE);
            checkStatement.setString(3, USER_COLUMN);
            checkStatement.setString(4, playerName);
            if (checkStatement.executeQuery().next()) {
                PreparedStatement updateStatement = connection.prepareStatement("UPDATE ? SET ? = ? WHERE ? = ?;");
                updateStatement.setString(1, MYSQL_TABLE);
                updateStatement.setString(2, INT_COLUMN);
                updateStatement.setInt(3, number);
                updateStatement.setString(4, USER_COLUMN);
                updateStatement.setString(5, playerName);
                updateStatement.execute();
            } else {
                PreparedStatement createStatement = connection.prepareStatement("INSERT INTO ? (?, ?) VALUES (?, ?);");
                createStatement.setString(1, MYSQL_TABLE);
                createStatement.setString(2, USER_COLUMN);
                createStatement.setString(3, INT_COLUMN);
                createStatement.setString(4, playerName);
                createStatement.setInt(5, number);
                createStatement.execute();
            }
        } catch (SQLException ex) {
            ex.printStackTrace();
        }
    }

    public static int get(String playerName) {
        try {
            PreparedStatement selectStatement = connection.prepareStatement("SELECT ? FROM ? WHERE ? = ?;");
            selectStatement.setString(1, INT_COLUMN);
            selectStatement.setString(2, MYSQL_TABLE);
            selectStatement.setString(3, USER_COLUMN);
            selectStatement.setString(4, playerName);

            ResultSet selectedResult = selectStatement.executeQuery();
            if (selectedResult.next()) {
                return selectedResult.getInt(1);
            }
        } catch (SQLException ex) {
            ex.printStackTrace();
        }
        return 0;
    }
}