Обсуждение: Applet - JDBC?

Greetings,
already I looked some people who work with postgresql in Brazil and not
obtained to explain me as to solve an error of connection gone off when my
applet tries to connect with postgreSQL.  A detailed description of the
error is soon to follow:

Erro: java.net.ConnectException: Connection refused: connect
Erro: Conexão negada. Verifique se o nome da máquina e a porta estão
corretos e se o postmaster está aceitando conexões TCP/IP

I am using [ PostgreSQL 8 ] and the applet meets in the following address:
http://www.ufgen.ufg.br/krub/jsp/graficos/monitoramento/ViewMonitoramento/


PS:  With the DB2 I did not have problems, however I am liking the form of
work with postgreSQL and if I not to obtain to decide this problem of
connection, go to have that to abandon postgreSQL.

In case that it will be possible to help me, I am describing still for its
analysis the archives [ pg_hba.conf ] and [ postgresql.conf ]



[pg_hba.conf]
...
# TYPE  DATABASE    USER        CIDR-ADDRESS          METHOD

# "local" is for Unix domain socket connections only
local   all         all                               trust
# IPv4 local connections:
local    all    postgres            trust
host    all     postgres         127.0.0.1    255.255.255.255          trust
host    all    all    0.0.0.0/0    trust
# IPv6 local connections:
#host    all         all         ::1/128               trust
...


[postgresql.conf]
...
listen_addresses = '*'
port = 5432
...

[Parameters that use to load the postmaster]
/usr/local/pgsql/bin/postmaster -i -p 5432 -o -e -D/usr/local/pgsql/data &

Leonardo.

"Leonardo Ribeiro Queiros" <leonardo@eee.ufg.br> writes:

> analysis the archives [ pg_hba.conf ] and [ postgresql.conf ]
>
>
>
> [pg_hba.conf]
> ...
> # TYPE  DATABASE    USER        CIDR-ADDRESS          METHOD
>
> # "local" is for Unix domain socket connections only
> local   all         all                               trust
> # IPv4 local connections:
> local    all    postgres            trust
> host    all     postgres         127.0.0.1    255.255.255.255          trust
> host    all    all    0.0.0.0/0    trust
> # IPv6 local connections:
> #host    all         all         ::1/128               trust


Your pg_hba.conf is missing a line that corresponds to the interface to the world
of the network card.

You should add a line for the subnet your computer is connected to, for example:

host    all         all         172.17.1.87       255.255.248.0     md5

This is for the connection from all computers in my subnet with md5 password-authentication.
If you do not use localhost as hostname in the connection string, this is needed even
for local connections.


--
Roland Walter                   mailto: rwa (at) mosaic-ag (dot) com
MOSAIC SOFTWARE AG               phone: +49 (0) 22 25 / 88 2-41 1
Am Pannacker 3                     fax: +49 (0) 22 25 / 88 2-20 1
D-53340 Meckenheim                http://www.mosaic-ag.com


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>>[pg_hba.conf]
>>...
>># TYPE  DATABASE    USER        CIDR-ADDRESS          METHOD
>>
>># "local" is for Unix domain socket connections only
>>local   all         all                               trust
>># IPv4 local connections:
>>local    all    postgres            trust
>>host    all     postgres         127.0.0.1    255.255.255.255          trust
>>host    all    all    0.0.0.0/0    trust
>># IPv6 local connections:
>>#host    all         all         ::1/128               trust
>>
>>
>
>
>Your pg_hba.conf is missing a line that corresponds to the interface to the world
>of the network card.
>
>You should add a line for the subnet your computer is connected to, for example:
>
>host    all         all         172.17.1.87       255.255.248.0     md5
>
>This is for the connection from all computers in my subnet with md5 password-authentication.
>If you do not use localhost as hostname in the connection string, this is needed even
>for local connections.
>
>

scary, however, is...

   host    all    all    0.0.0.0/0    trust

I read that to say, trust anyone from any IP to be anyone they say they want to be.

wouldn't that trump your subnet md5 line ?

Leonardo Ribeiro Queiros wrote:

> Erro: java.net.ConnectException: Connection refused: connect
> Erro: Conexão negada. Verifique se o nome da máquina e a porta estão
> corretos e se o postmaster está aceitando conexões TCP/IP

I guess this is a localization of "Connection refused"?

Can you use psql running on the client machine to connect to the server
successfully? If not, JDBC isn't going to work either. I'd check for
firewalls between the client and server.

 From JDBC's perspective, it's tried to establish a TCP connection to
port 5432 on your server and got a connection refused error. There is
nothing that the driver can do about that, you've got a connectivity
problem somewhere.

-O