import java.sql.*;

public class JdbcTest {
	public static void main(String[] args) throws Exception 
	{
		Class.forName("org.postgresql.Driver");
		Connection conn = DriverManager.getConnection("jdbc:postgresql://localhost/testdb", "username", "pw");
		
		ResultSet rs = conn.prepareStatement("SELECT * FROM test").executeQuery();
		while(rs.next())
			System.out.println(rs.getString(1));
	}
}