Tomcat配置访问日志日志支持的属性格式字符特殊说明 - WEB服务

一、Tomcat配置访问日志

配置路径：server.xml/Server/Service/Engine/Host/Valve
<Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs" pattern="%h %l %u %t "%r" %s %b" prefix="localhost_access_log." suffix=".txt"/>
<Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs" pattern="%{begin:yyyy-MM-dd HH:mm:ss.SSS}t %l %u %h "%r" %s %D %F %b" prefix="localhost_access_log." suffix=".txt" buffered="false"/>

日志支持的属性：
fileDateFormat，配置文件名的时间戳，默认yyyy-MM-dd，时间戳变化后文件将会滚动
rotatable，是否支持滚动，默认支持
renameOnRotate，当前文件是否包含时间戳
conditionIf，ServletRequest.getAttribute("attr") != null，时输出日志
conditionUnless，ServletRequest.getAttribute("attr") == null，时输出日志
pattern，日志格式
buffered，是否进行缓存，默认为true，如果false立即输出日志

格式字符：

%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 enableLookups for the connector is 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. See also %{xxx}p below.
%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
%F - Time taken to commit the response, in millis
%I - Current request thread name (can compare later with stacktraces)

数据来源于请求头、响应头、cookie、会话：

%{xxx}i write value of incoming header with name xxx
%{xxx}o write value of outgoing header with name xxx
%{xxx}c write value of cookie with name xxx
%{xxx}r write value of ServletRequest attribute with name xxx
%{xxx}s write value of HttpSession attribute with name xxx
%{xxx}p write local (server) port (xxx==local) or remote (client) port (xxx=remote)
%{xxx}t write timestamp at the end of the request formatted using the SimpleDateFormat pattern

特殊说明：

1、生产环境必须设置buffered为true；

2、%{xxx}r，如果xxx属性不存在则输出"-"；

3、%D接收到第一字节到发送最后一字节，包含网络影响；

4、%F接受到第一字节到发送第一个字节，不包含网络影响；