Using log4j to send email reports via the SMTPAppender

Question

I\'m trying to use log4j to send emailable reports that contain the logging statements from a background process. I want one email sent for each process run, not one email

Answer 1

You shouldn't use any of log4j's methods, you should configure it properly instead.

First of all, define in your log4j.properties file your appender properly:

#CONFIGURE SMTP
log4j.appender.email=org.apache.log4j.net.SMTPAppender
log4j.appender.email.SMTPHost=mail.mydomain.com
log4j.appender.email.SMTPUsername=myuser@mydomain.com
log4j.appender.email.SMTPPassword=mypw
log4j.appender.email.From=myuser@mydomain.com
log4j.appender.email.To=myuser@mydomain.com
log4j.appender.email.Subject=Log of messages
log4j.appender.email.BufferSize=1
log4j.appender.email.EvaluatorClass=TriggerLogEvent
log4j.appender.email.layout=org.apache.log4j.PatternLayout
log4j.appender.email.layout.ConversionPattern=%m

Note: code taken from this post. More information can be obtained in SMTPAppender API.

Next, make a special class that will be used just for sending email. Example:

package com.foo.mailer;
import org.apache.log4j.Logger;

public class Mailer {
   private static final Logger logger = Logger.getLogger(Mailer.class);

   public void logMail(String mailString) {
      logger.info(mailString);
   }
}

Next, put in log4j.properties configuration for this class:

# INFO level will be logged
log4j.logger.com.foo.mailer = INFO, email
# turn off additivity
log4j.additivity.com.foo.mailer = false

Now, whenever you want to send an email using log4j, put this in your code:

new Mailer().logMail("This mail should be sent");

Disclaimer: I haven't tested any of this code.