利用Filter输出HTTP请求报文

有时候开发需要抓取HTTP请求报文进行数据分析，从浏览器发出的请求还比较好操作，比较工具比较多，从移动客户端上来的请求，除了数据利用网络监听等工具之外，还可以通过request对象进行报文输出分析。
tomcat6为我们提供了org.apache.catalina.valves.RequestDumperValve工具，可以将请求报文输出，在在server.xml中将

 <Valve className="org.apache.catalina.valves.RequestDumperValve"/>

取消注释即可（来源：http://www.tuicool.com/articles/Nj6RN3）。
tomcat7中，提供了org.apache.catalina.filters.RequestDumperFilter过滤器，可见官方文档：https://tomcat.apache.org/tomcat-7.0-doc/config/filter.html#Request_Dumper_Filter
我这里直接翻到RequestDumperFilter的源码：源码，仿照源码写一份自己的dumperfilter：

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.sql.Timestamp;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Enumeration;
import java.util.Locale;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;

public final class OutputRequestFilter implements Filter {

    public void destroy() {
    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        // Render the generic servlet request properties
        StringBuilder writer = new StringBuilder();
        writer.append(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date())+":");
        writer.append("\n");
        writer.append("Request Received at " + (new Timestamp(System.currentTimeMillis())));
        writer.append("\n");
        writer.append(" characterEncoding=" + request.getCharacterEncoding());
        writer.append("\n");
        writer.append("     contentLength=" + request.getContentLength());
        writer.append("\n");
        writer.append("       contentType=" + request.getContentType());
        writer.append("\n");
        writer.append("            locale=" + request.getLocale());
        writer.append("\n");
        writer.append("           locales=");
        Enumeration locales = request.getLocales();
        boolean first = true;
        while (locales.hasMoreElements()) {
            Locale locale = (Locale) locales.nextElement();
            if (first)
                first = false;
            else
                writer.append(", ");
            writer.append(locale.toString());
        }
        writer.append("\n");
        Enumeration names = request.getParameterNames();
        while (names.hasMoreElements()) {
            String name = (String) names.nextElement();
            writer.append("         parameter=" + name + "=");
            String values[] = request.getParameterValues(name);
            for (int i = 0; i < values.length; i++) {
                if (i > 0)
                    writer.append(", ");
                writer.append(values[i]);
            }
            writer.append("\n");
        }
        writer.append("          protocol=" + request.getProtocol());
        writer.append("\n");
        writer.append("        remoteAddr=" + request.getRemoteAddr());
        writer.append("\n");
        writer.append("        remoteHost=" + request.getRemoteHost());
        writer.append("\n");
        writer.append("            scheme=" + request.getScheme());
        writer.append("\n");
        writer.append("        serverName=" + request.getServerName());
        writer.append("\n");
        writer.append("        serverPort=" + request.getServerPort());
        writer.append("\n");
        writer.append("          isSecure=" + request.isSecure());
        writer.append("\n");

        // Render the HTTP servlet request properties
        if (request instanceof HttpServletRequest) {
            writer.append("---------------------------------------------");
            HttpServletRequest hrequest = (HttpServletRequest) request;
            writer.append("       contextPath=" + hrequest.getContextPath());
            writer.append("\n");
            Cookie cookies[] = hrequest.getCookies();
            if (cookies == null)
                cookies = new Cookie[0];
            for (int i = 0; i < cookies.length; i++) {
                writer.append("            cookie=" + cookies[i].getName() + "=" + cookies[i].getValue());
                writer.append("\n");
            }
            names = hrequest.getHeaderNames();
            while (names.hasMoreElements()) {
                String name = (String) names.nextElement();
                String value = hrequest.getHeader(name);
                writer.append("            header=" + name + "=" + value);
                writer.append("\n");
            }
            writer.append("            method=" + hrequest.getMethod());
            writer.append("\n");
            writer.append("          pathInfo=" + hrequest.getPathInfo());
            writer.append("\n");
            writer.append("       queryString=" + hrequest.getQueryString());
            writer.append("\n");
            writer.append("        remoteUser=" + hrequest.getRemoteUser());
            writer.append("\n");
            writer.append("requestedSessionId=" + hrequest.getRequestedSessionId());
            writer.append("\n");
            writer.append("        requestURI=" + hrequest.getRequestURI());
            writer.append("\n");
            writer.append("       servletPath=" + hrequest.getServletPath());
            writer.append("\n");

            if(hrequest.getMethod().equals("POST")){
                writer.append("====================Body===================");
                String s=null;
                BufferedReader br = new BufferedReader(new InputStreamReader(hrequest.getInputStream()));
                while((s=br.readLine())!=null){
                    writer.append(s);
                }
                writer.append("\n");
                writer.append("====================Body End===================");
            }
        }

        writer.append("\n");
        writer.append("=============================================\n\n\n");

        System.out.println(writer);
        PrintWriter pw = new PrintWriter(new File("/usr/tomcat/apache-tomcat-7.0.75/requestDumper.txt"));
        pw.append(writer);
        pw.flush();
        pw.close();

        // Pass control on to the next filter
        chain.doFilter(request, response);

    }


    public void init(FilterConfig filterConfig) throws ServletException {

    }

}

特此以记。