Mail API & Retrying Host

Posted on 2002-06-18
Last Modified: 2012-05-04
I have a working app that send mail successfully when the mail server is ok (obvious so far!).

What I want to be able to do is detect that the host is not available and retry with a second host.

I'd like to be able to detect this before sending a message, such as in the code:

Session session = Session.getInstance(props, null);
MimeMessage message = new MimeMessage(session);

Where props contains the host name.

I know that the host could fail at any point after this, and during the sending of a particular message.

It would be good to be able to catch an exception (MessagingException?) at the point of making the host connection, and if it fails, try another host. It would be even better to be able to detect the failed host connection during sending each message and retry with another host, but I think that is more difficult, given the connection has already been made.

Any ideas?
Question by:harrywillis
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Accepted Solution

Venci75 earned 100 total points
ID: 7087659
you can try something like this:

try {
  Session session = Session.getInstance(props, null);
} catch (MessagingException e) {
  // you will be here if 'connect' has failed

Author Comment

ID: 7087752
Thanks. I want something more like:

try {
  Session session = Session.getInstance(props, null);
} catch (MessagingException e) {
  // try connection to 2nd host

Or even better, when sending a message and the host cannot be contacted, to retry with another host.

Expert Comment

ID: 7134736
well if Session.getInstance() fails then session will be null. u can check for the null condition and use a While loop to connect to other host. this ways u need only one try and catch and u will be saved form nested try and catch. when connection is sucessful u can break out of while loop.
LVL 35

Expert Comment

ID: 8860469
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