java.lang.IllegalArgumentException: Invalid format: "XXX" is malformed at "XXX"

1. an example error

'java.lang.IllegalArgumentException: Invalid format:
"30/Jan/2015:15:01:03" is malformed at "Jan/2015:15:01:03"' error

2. check the LANG of system

echo $LANG

3. change it if it is not "en_US.UTF-8"

- For instance, at CentOS
- vi /etc/sysconfig/i18n 
- LANG="en_US.UTF-8"
- restart the system