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

public class MySQLAccess {

    private Connection connect = null;
    private Statement statement = null;
    private PreparedStatement preparedStatement = null;
    private ResultSet resultSet = null;

    public String getResultSet() throws SQLException {
        resultSet = statement.executeQuery("select * from examen.material");
        return writeResultSet(resultSet);
    }

    public void inserare(String model, String culoare, String lungime) throws Exception {
        preparedStatement = connect
                .prepareStatement("insert into examen.material values (default, ?, ?, ?)");
        preparedStatement.setString(1, model);
        preparedStatement.setString(2, culoare);
        preparedStatement.setString(3, lungime);
        preparedStatement.executeUpdate();
    }

    public void readDataBase() throws Exception {
        try {
            // Incarca driverul MYSQL
            Class.forName("com.mysql.jdbc.Driver");

            // Creeaza conexiunea cu baza de data
            connect = DriverManager.getConnection("jdbc:mysql://localhost/examen?" + "user=root&password=");

            // Statementurile ne ajuta sa facem query
            statement = connect.createStatement();

            // Afisam toata baza de date
            resultSet = statement.executeQuery("select * from examen.material");
            writeResultSet(resultSet);

            System.out.println("---------------------------------------");

        } catch (Exception e) {
            throw e;
        } finally {
            close();
        }

    }

    private String writeResultSet(ResultSet resultSet) throws SQLException {
        // ResultSet is initially before the first data set
        String str = "NU AFISEAZA NIMIC";
        while (resultSet.next()) {
            // It is possible to get the columns via name
            // also possible to get the columns via the column number
            // which starts at 1
            // e.g. resultSet.getSTring(2);

            String model = resultSet.getString("model");
            String culoare = resultSet.getString("culoare");
            String lungime = resultSet.getString("lungime");
            str = str + ("\nModel: " + model + "Culoare: " + culoare + "Lungime: " + lungime);
        }

        return str;
    }

    // You need to close the resultSet
    private void close() {
        try {
            if (resultSet != null) {
                resultSet.close();
            }

            if (statement != null) {
                statement.close();
            }

            if (connect != null) {
                connect.close();
            }
        } catch (Exception e) {

        }
    }

}