I want to create a folder and write a file in the created folder in an Amazon EBS
volume from a Java Servlet installed on Amazon EC2 running Ubuntu.
I have
Looks like your folder does not have the correct read/write permissions.
Try granting read-write access to all users to the directory in question, e.g.:
sudo chmod -R ugo+rw /mnt/my-address
If you are uncomfortable with granting write permissions to all, you could fine tune the permissions by playing with ownership and groups, but I would need more info about your setup to help you with that.
Edit: if the ec2-user is the only one needing access, you could change the ownership of the directory to that user and then grant access to only him:
sudo chown -R ec2-user:ec2-user /mnt/my-address
sudo chmod -R u+rw,go-rw /mnt/my-address