* %a - 远端IP地址 
    * %A - 本地IP地址 
    * %b - 发送的字节数,不包括HTTP头,如果为0,使用"-" 
    * %B - 发送的字节数,不包括HTTP头 
    * %h - 远端主机名(如果resolveHost=false,远端的IP地址) 
    * %H - 请求协议 
    * %l - 从identd返回的远端逻辑用户名(总是返回 '-') 
    * %m - 请求的方法(GET,POST,等) 
    * %p - 收到请求的本地端口号 
    * %q - 查询字符串(如果存在,以 '?'开始) 
    * %r - 请求的第一行,包含了请求的方法和URI 
    * %s - 响应的状态码 
    * %S - 用户的session ID 
    * %t - 日志和时间,使用通常的Log格式 
    * %u - 认证以后的远端用户(如果存在的话,否则为'-') 
    * %U - 请求的URI路径 
    * %v - 本地服务器的名称 
    * %D - 处理请求的时间,以毫秒为单位 
    * %T - 处理请求的时间,以秒为单位 
    - %a - Remote IP address
    
- %A - Local IP address
    
- %b - Bytes sent, excluding HTTP headers, or '-' if zero
    
- %B - Bytes sent, excluding HTTP headers
    
- %h - Remote host name (or IP address if resolveHostsis false)
- %H - Request protocol
    
- %l - Remote logical username from identd (always returns '-')
    
- %m - Request method (GET, POST, etc.)
    
- %p - Local port on which this request was received
    
- %q - Query string (prepended with a '?' if it exists)
    
- %r - First line of the request (method and request URI)
    
- %s - HTTP status code of the response
    
- %S - User session ID
    
- %t - Date and time, in Common Log Format
    
- %u - Remote user that was authenticated (if any), else '-'
    
- %U - Requested URL path
    
- %v - Local server name
    
- %D - Time taken to process the request, in millis
    
- %T - Time taken to process the request, in seconds
    
- %I - current request thread name (can compare later with stacktraces) 
    - %{xxx}ifor incoming request headers
- %{xxx}ofor outgoing response headers
- %{xxx}cfor a specific request cookie
- %{xxx}rxxx is an attribute in the ServletRequest
- %{xxx}sxxx is an attribute in the HttpSession