converting to MD5

Hi there, I was wondering what is needed to done on both the postgres
& client side to connect via MD5.  Right now, we are connecting fine
by just specifying password in pg_hba.conf:
host   database      user xxx.xxx.xxx.xxx   xxx.xxx.xxx.xxx   password

But I would like to change this to use:
host   database      user xxx.xxx.xxx.xxx   xxx.xxx.xxx.xxx   md5

I have the user stored in pg_shadow (note: the passwd listed is not
the real one):
 usename  | usesysid | usecreatedb | usesuper | usecatupd |
   passwd                | valuntil | useconfig
 user  |      100 | t           | f        | f         |
md59033f409a99f207fa816b990467a9999 |          |

On the client side, we are using pg74.215.jdbc2.jar with code based on
the example given on
http://jdbc.postgresql.org/documentation/pgjdbc.html

    String url = "jdbc:postgresql://" + host + "/" + database;
    try {
    Class.forName("org.postgresql.Driver");

                                                          con =
DriverManager.getConnection(url, userID, password);

                                                          }

I can generate the same password that matches the one stored in
pg_shadow.  So how do I specify that the password I am sending is in
MD5?  Any help would be appreciated.

Thanks, O.