In Java, how do I set a return type if an exception occurs?

hey all, I'm new to Java and was wondering if I define a method to return a database object

like

import java.sql.*;

public class DbConn {

    public Connection getConn() {
        Connection conn;
        try {
            Class.forName("com.mysql.jdbc.Driver").newInstance();
            if(System.getenv("MY_ENVIRONMENT") == "development") {
                String hostname = "localhost";
                String username = "root";
                String password = "root";
            }
            conn = DriverManager.getConnection("jdbc:mysql:///mydb", username, password);
            return conn;
        } catch(Exception e) {
            throw new Exception(e.getMessage());
        }

    }

}

if the connection fails when I try to create it what should I return? eclipse is telling me I have to return a Connection object but if it fails I'm not sure what to do.

thanks!

UPDATED CODE TO LET EXCEPTION BUBBLE:

public class DbConn {

    public Connection getConn() throws SQLException {
        Connection conn;
        String hostname = "localhost";
        String username = "root";
        String password = "root";

        Class.forName("com.mysql.jdbc.Driver").newInstance();
        if(System.getenv("MY_ENVIRONMENT") != "development") {
            hostname = "localhost";
            username = "produser";
            password = "prodpass";
        }
        conn = DriverManager.getConnection("jdbc:mysql:///mydb", username, password);
        return conn;

    }

}