DatosBaso

package jdbc;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

public class Database {

    private Connection connection;
    private Statement statement;
    private PreparedStatement preparedStatement;
    private ResultSet resultSet;

    private static Database instance;

    public Database() {
       try {
          Class.forName("com.mysql.jdbc.Driver");
     connection = DriverManager.getConnection("jdbc:mysql://10.100.6.166:3306/derrotado", "derrotado", "fracaso");
} catch (ClassNotFoundException | SQLException ex) {
    System.out.println("Error: " + ex.getMessage());
}
    }

    public static Database getInstance() {
        if (instance == null) {
            return new Database();
        }
        return instance;
    }

    public void select(String query) {
        if (connection != null) {
            try {
                statement = connection.createStatement();
                resultSet = statement.executeQuery(query);
            } catch (SQLException ex) {
                System.out.println("Error: " + ex.getMessage());
            }
        }
    }

    public void select(String query, List<Object> params) {
        if (connection != null) {
            try {
                int count = 0;
                preparedStatement = connection.prepareStatement(query);
                for (Object object : params) {
                    preparedStatement.setObject((count), object);
                    count++;
                }
                resultSet = preparedStatement.executeQuery();
            } catch (SQLException ex) {
                System.out.println("Error: " + ex.getMessage());
            }
        }
    }

    public boolean insert(String query, List<Object> params) {
        return alter(query, params);
    }

    public boolean update(String query, List<Object> params) {
        return alter(query, params);
    }

    public boolean delete(String query, List<Object> params) {
        return alter(query, params);
    }

    private boolean alter(String query, List<Object> params) {
        int status = 0;
        int count = 1;

        if (connection != null) {
            try {
                preparedStatement = connection.prepareStatement(query);
                for (Object object : params) {
                    preparedStatement.setObject((count), object);
                    count++;
                }
                status = preparedStatement.executeUpdate();
            } catch (Exception ex) {
                System.out.println(ex.getMessage());
            }
        }
        return (status > 0);
    }

    @Override
    public void finalize() {
        try {
            disconnection();
            super.finalize();
        } catch (Throwable ex) {
            System.out.println("Error: " + ex.getMessage());
        }
    }

    private void disconnection() {
        try {
            if (resultSet != null) {
                resultSet.close();
                resultSet = null;
            }
            if (statement != null) {
                statement.close();
                statement = null;
            }
            if (preparedStatement != null) {
                preparedStatement.close();
                preparedStatement = null;
            }
            if (connection != null) {
                connection.close();
                connection = null;
            }
        } catch (SQLException ex) {
            System.out.println("Error: " + ex.getMessage());
        }
    }

    public ResultSet getResultSet() {
        return resultSet;
    }
}