import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
public class Main {
public static void main(String[] args) throws Exception {
String hostname = "", dbname = "", username = "", password = "";
Class.forName("org.postgresql.Driver");
Connection connection = DriverManager.getConnection("jdbc:postgresql://"
+ hostname + "/" + dbname, username, password);
ResultSet rs = connection.createStatement().executeQuery(
"select version() as version");
while (rs.next()) {
System.out.println(rs.getString("version"));
}
}
}