tomcat的acess_log打印post请求参数,分析日志

有的时候服务器端接口允许请求的方式多样化且不过定，没有nginx的内网服务还需要统计分析post请求日志

1) 在项目中加入相应的包和类，加载那里无所谓，只要web.xml配置正确即可

package filters; 

import java.io.IOException; 

import java.util.Enumeration; 

import javax.servlet.*; 

public final class PostDataDumperFilter implements Filter { 

private FilterConfig filterConfig
= null; 

public void destroy() { 

this.filterConfig = null; 

} 

public void doFilter(ServletRequest request, ServletResponse response,FilterChain chain)
throws IOException, ServletException { 

if (filterConfig == null) 

return; 

Enumeration names = request.getParameterNames(); 
StringBuffer output=new StringBuffer(); 

while (names.hasMoreElements()) { 

String name = (String) names.nextElement(); 

output.append(name+"="); 

String values[] = request.getParameterValues(name); 

for (int i = 0; i < values.length; i++) { 

if (i > 0) output.append("' "); 

output.append(values[i]); 

} 

if(names.hasMoreElements()) output.append("&"); 

} 

request.setAttribute("post", output); 

chain.doFilter(request, response); 

} 

public void init(FilterConfig filterConfig)
throws ServletException { 

this.filterConfig = filterConfig; 

} 

} 

2) 配置web.xm，一般在路径 main/webapps/WEB-INF/web.xml: 

<filter> 

<filter-name>post-data-dumper-filter</filter-name> 

<filter-class>filters.PostDataDumperFilter</filter-class> 

</filter> 

<filter-mapping> 

<filter-name>post-data-dumper-filter</filter-name> 

<url-pattern>/*</url-pattern> 

</filter-mapping> 

3) now you have the attribute postdata for each request and you can easily log it in access valve, for example: 
<Valve className="org.apache.catalina.valves.AccessLogValve" directory="logs" 

                prefix="localhost_access_log." suffix=".txt" 

                pattern='%h %p %H %l %u %t "%r" params={%{post}r} %s %bbytes %Dms' resolveHosts="false"/>