Pingdom - With website monitoring from Pingdom you will be the first to know when your website is down. No installation required. 30-day free trial.
tinylog - tinylog is a lightweight logging framework with static logger class for Java and can be configured...
StatusCake - Website Uptime Monitoring & Alerts – Free Unlimited Downtime Monitoring
Apache Log4j - Log4j is a logging framework (APIs) written in Java.
Better Uptime - We call you when your website goes down
LOGBack - Logging framework