Connection refused. HELP ME!!!!

Hello.
I have installed postgresql with de jdbc driver, but I can't run the
example of the jdbc faq (http://www.fankhausers.com/postgresql/jdbc/). I
obtain:
***Exception:
Connection refused. Check that the hostname and port are correct and
that the postmaster is accepting TCP/IP connections.
Connection refused. Check that the hostname and port are correct and
that the postmaster is accepting TCP/IP connections.
         at
org.postgresql.jdbc1.AbstractJdbc1Connection.openConnection(AbstractJdbc1Connection.java:161)
         at org.postgresql.Driver.connect(Driver.java:120)
         at java.sql.DriverManager.getConnection(DriverManager.java:512)
         at java.sql.DriverManager.getConnection(DriverManager.java:171)
         at HelloPostgresql.<init>(HelloPostgresql.java:34)
         at HelloPostgresql.main(HelloPostgresql.java:115)

I have modified my pg_hba.conf(host all 127.0.0.1 255.0.0.0 trust), and
my posgresql.conf(tcpip_socket = true) to admit tcp socket connections.
What can I do?
Thanks.