Tomcat example source code file (RequestDumperFilter.java)

This example Tomcat source code file (RequestDumperFilter.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Tomcat tags/keywords

cookie, enumeration, http, httpservletrequest, httpservletrequest, io, locale, printwriter, request, requestdumperfilter, requestdumperfilter, response, servlet, servletexception, servletexception, string, string, stringbuffer, stringwriter, util

The Tomcat RequestDumperFilter.java source code

/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License.  You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/


package filters;


import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.sql.Timestamp;
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;


/**
 * Example filter that dumps interesting state information about a request
 * to the associated servlet context log file, before allowing the servlet
 * to process the request in the usual way.  This can be installed as needed
 * to assist in debugging problems.
 *
 * @author Craig McClanahan
 * @version $Revision: 500674 $ $Date: 2007-01-28 00:15:00 +0100 (dim., 28 janv. 2007) $
 */

public final class RequestDumperFilter implements Filter {


    // ----------------------------------------------------- Instance Variables


    /**
     * The filter configuration object we are associated with.  If this value
     * is null, this filter instance is not currently configured.
     */
    private FilterConfig filterConfig = null;


    // --------------------------------------------------------- Public Methods


    /**
     * Take this filter out of service.
     */
    public void destroy() {

        this.filterConfig = null;

    }


    /**
     * Time the processing that is performed by all subsequent filters in the
     * current filter stack, including the ultimately invoked servlet.
     *
     * @param request The servlet request we are processing
     * @param result The servlet response we are creating
     * @param chain The filter chain we are processing
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet error occurs
     */
    public void doFilter(ServletRequest request, ServletResponse response,
                         FilterChain chain)
	throws IOException, ServletException {

        if (filterConfig == null)
	    return;

	// Render the generic servlet request properties
	StringWriter sw = new StringWriter();
	PrintWriter writer = new PrintWriter(sw);
	writer.println("Request Received at " +
		       (new Timestamp(System.currentTimeMillis())));
	writer.println(" characterEncoding=" + request.getCharacterEncoding());
	writer.println("     contentLength=" + request.getContentLength());
	writer.println("       contentType=" + request.getContentType());
	writer.println("            locale=" + request.getLocale());
	writer.print("           locales=");
	Enumeration locales = request.getLocales();
	boolean first = true;
	while (locales.hasMoreElements()) {
	    Locale locale = (Locale) locales.nextElement();
	    if (first)
	        first = false;
	    else
	        writer.print(", ");
	    writer.print(locale.toString());
	}
	writer.println();
	Enumeration names = request.getParameterNames();
	while (names.hasMoreElements()) {
	    String name = (String) names.nextElement();
	    writer.print("         parameter=" + name + "=");
	    String values[] = request.getParameterValues(name);
	    for (int i = 0; i < values.length; i++) {
	        if (i > 0)
		    writer.print(", ");
		writer.print(values[i]);
	    }
	    writer.println();
	}
	writer.println("          protocol=" + request.getProtocol());
	writer.println("        remoteAddr=" + request.getRemoteAddr());
	writer.println("        remoteHost=" + request.getRemoteHost());
	writer.println("            scheme=" + request.getScheme());
	writer.println("        serverName=" + request.getServerName());
	writer.println("        serverPort=" + request.getServerPort());
	writer.println("          isSecure=" + request.isSecure());

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

	// Log the resulting string
	writer.flush();
	filterConfig.getServletContext().log(sw.getBuffer().toString());

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

    }


    /**
     * Place this filter into service.
     *
     * @param filterConfig The filter configuration object
     */
    public void init(FilterConfig filterConfig) throws ServletException {

	this.filterConfig = filterConfig;

    }


    /**
     * Return a String representation of this object.
     */
    public String toString() {

	if (filterConfig == null)
	    return ("RequestDumperFilter()");
	StringBuffer sb = new StringBuffer("RequestDumperFilter(");
	sb.append(filterConfig);
	sb.append(")");
	return (sb.toString());

    }


}