Re: java mail and thread

lipska the kat <"nospam at neversurrender dot co dot uk">
Fri, 25 Oct 2013 12:30:16 +0100
On 24/10/13 22:28, wrote:

Good evening to all .
I'm designing an application that has the task of sending the email automatically taking the recipients from a db.
To send email I created a special class that receives the string with the recipient's address and sends mail.
The instruction to send the message:

Transport.send (msg ) ;

I noticed that this statement takes a bit of seconds before releasing
flow and therefore are unable to use the other functions of the application . I thought , therefore, to use a technology where each object of the class that sends the email implements Runnable and then i use it like a thread.
I noticed , however, that there are problems because sometimes 20 over 50 emails fail and the instruction that give me the error is

Transport.send (msg ) ; : Connection closed by remote host

and seems to be the fact that the thread dies too fast after the statement
Transport.send (msg ) ;
So I inserted a Thread.sleep ( 10000 ) ;
but sometimes I goes equally mistaken, then I tried to employ
t.join ();
but it blocks the flow (basically waiting for the thread to end it all before giving way to another )
What can I do ?
If you need I can write a few lines of code to make you understand how I'm implementing the functionality described

I look forward ideas


How about something like this (outline only, off the top of my head)

If you want to send the same message to all recipients
then simply.

Transport transport = session.getTransport(TRANSPORT);
//set up session
//set up message
MimeMessage message = new MimeMessage(session);
//for each recipient
message.addRecipient(Message.RecipientType.TO, toAddress); //or CC, BCC
Transport transport = session.getTransport("smtp");
transport.connect(HOST, USERNAME, PASSWORD);
transport.sendMessage(message, message.getAllRecipients());

wrap it in a thread if you don't want the main to block

If you want to send a different message to each recipient then something

class MailMachine implements Runnable{

    EmailAddressServer eas;
         EmailMessageServer ems;
         List<String> emailAddresses = eas.getAddresses();
         //set up mail session
         Session session = Session.getInstance(properties);

         public void run(){
        for(String email: emailAddresses){
                         MimeMessage message = new MimeMessage(session);
                         String msg = ems.getMessage(email); //whatever
            //blocking IO

public class Foo{

                 // do stuff
        MailMachine mm = new MailMachine();
                 Thread t = new Thread(mm);
        //do more stuff

Lipska the Kat?: Troll hunter, sandbox destroyer
and farscape dreamer of Aeryn Sun
GNU/Linux user #560883 -

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