 <p>
 Name pattern is a string that may include some special substrings, which will
 be replaced to generate output files:
 <ul>
 <li>"/" represents the local pathname separator</li>
 <li>"%g" represents the generation number to distinguish rotated logs</li>
 <li>"%h" represents the home directory of the current user, which is
 specified by "user.home" system property</li>
 <li>"%t" represents the system's temporary directory</li>
 <li>"%u" represents a unique number to resolve conflicts</li>
 <li>"%%" repr