public void connectToAndQueryDatabase(String username, String password) {

    Class.forName("com.mysql.jdbc.Driver");

    Connection con = DriverManager.getConnection(

                         "jdbc:myDriver:myDatabase",

                         username,

                         password);

    Statement stmt = con.createStatement();

    ResultSet rs = stmt.executeQuery("SELECT a, b, c FROM Table1");

    while (rs.next()) {

        int x = rs.getInt("a");

        String s = rs.getString("b");

        float f = rs.getFloat("c");

    }

}

Driver d = new com.mysql.jdbc.Driver();

Class<?> c = Class.forName("YourPluginName"); 

Plugin plugin = (Plugin) c.newInstance(); 

Class.forName("com.mysql.jdbc.Driver");

con = DriverManager.getConnection(url);

pubic interface JdbcConstants {

  public static final String DRIVER = "com.mysql.jdbc.Driver";

  public static final String URL = "jdbc:mysql://localhost:3306/sample_db?user=root&password=your_password";

}

public class DAOCustomer implements JdbcConstants {

  public void connectToAndQueryDatabase(String username, String password) {  

    Class.forName(DRIVER);

    con = DriverManager.getConnection(URL);

System.setProperty("jdbc.drivers","com.mysql.jdbc.Driver");

// Factory method. Loads the driver by given classname. It actually returns a 

// concrete Class<Driver>. However, we don't need it here, so we just ignore it.

// It can be any driver class name. The MySQL one here is just an example.

// Under the covers, it will do DriverManager.registerDriver(new Driver()).

Class.forName("com.mysql.jdbc.Driver");

// Abstract factory. This lets the driver return a concrete connection for the

// given URL. You can just declare it against java.sql.Connection interface.

// Under the covers, the DriverManager will find the MySQL driver by URL and call

// driver.connect() which in turn will return new ConnectionImpl().

Connection connection = DriverManager.getConnection(url);

// Abstract factory. This lets the driver return a concrete statement from the

// connection. You can just declare it against java.sql.Statement interface.

// Under the covers, the MySQL ConnectionImpl will return new StatementImpl().

Statement statement = connection.createStatement();

// Abstract factory. This lets the driver return a concrete result set from the

// statement. You can just declare it against java.sql.ResultSet interface.

// Under the covers, the MySQL StatementImpl will return new ResultSetImpl().

ResultSet resultSet = statement.executeQuery(sql);

public void insertRecord(Customer customer) throws SQLException {

        String INSERT_USERS_SQL = "INSERT INTO users (name, address, weight) VALUES (?, ?, ?)";

        // Step 1: Establishing a Connection

        try (Connection connection = DriverManager

            .getConnection(URL, USERNAME, PASSWORD);

            // Step 2:Create a statement using connection object

            PreparedStatement preparedStatement = connection.prepareStatement(INSERT_USERS_SQL)) {

            preparedStatement.setString(1, customer.getName());

            preparedStatement.setString(2, customer.getAddress());

            preparedStatement.setInt(3, customer.getAge());

            // Step 3: Execute the query or update query

            preparedStatement.executeUpdate();

        } catch (SQLException e) {

            // print SQL exception information

            printSQLException(e);

        }

        // Step 4: try-with-resource statement will auto close the connection.

    }

//jdbcTemplate 

 public int insert(Customer customer) {

  return jdbcTemplate.update(

    "insert into customer (name, address, weight) values(?, ?, ?)",

    customer.getName(), customer.getAddress(), customer.getWeight());

 }

 public int update(Customer customer) {

  return jdbcTemplate.update(

    "update customer set name=?, address=?, weight=? where id =?",

    customer.getName(), customer.getAddress(), customer.getWeight(), customer.getId());

 }

 public int delete(Long id) {

  return jdbcTemplate.update(

    "delete from customer where id =?", id);

 }

 public Customer findOne(Long id) {

     return this.jdbcTemplate.queryForObject( "select id, name, address, weight from customer where id = ?", new Object[]{id}, new CustomerMapper());

 }

 public List<Customer> findAll() {

     return this.jdbcTemplate.query( "select id, name, address, weight from customer", new CustomerMapper());

 }

 private static final class CustomerMapper implements RowMapper<Customer> {

     public Customer mapRow(ResultSet rs, int rowNum) throws SQLException {

         Customer customer = new Customer();

         customer.setId(rs.getLong("id"));

         customer.setName(rs.getString("name"));

         customer.setAddress(rs.getString("address"));

         customer.setWeight(rs.getInt("weight"));

         return customer;

     }

 }