code fragment gives a simple example of these three steps

public void connectToAndQueryDatabase(String username, String password) {

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");
}
// ...