How can I calculate the request time ?

Question

Hello,
How can I calculate the total consume time in each request ?
For example, I want to start calculating the time when I click on a Link or a button and the end time when it completed load the page !
Eric

Answer 1

You could use a filter like this one:
import java.io.*;
import java.net.*;
import java.util.*;
import java.text.*;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
public class TimeFilter implements Filter {
    // The filter configuration object we are associated with.  If
    // this value is null, this filter instance is not currently
    // configured.
    private FilterConfig filterConfig = null;
    private static final boolean debug = false;
    private long start = 0;
    private long end = 0;
    public TimeFilter() {
    private void doBeforeProcessing(ServletRequest request, ServletResponse response)
    throws IOException, ServletException {
        if (debug) log("CalendarFilter:DoBeforeProcessing");
        System.out.print("In Filter  ");
        this.start = System.currentTimeMillis();
        System.out.println((new java.util.Date()).toString() +
                           " start request ");
    private void doAfterProcessing(ServletRequest request, ServletResponse response)
    throws IOException, ServletException {
        if (debug) log("TimeFilter:DoAfterProcessing");
        System.out.println("Completion Time = " + (System.currentTimeMillis() - start));
     * @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 (debug) log("TimeFilter:doFilter()");
        doBeforeProcessing(request, response);
        Throwable problem = null;
        try {
            chain.doFilter(request, response);
        catch(Throwable t) {
            problem = t;
            t.printStackTrace();
        doAfterProcessing(request, response);
        // If there was a problem, we want to rethrow it if it is
        // a known type, otherwise log it.
        if (problem != null) {
            if (problem instanceof ServletException) throw (ServletException)problem;
            if (problem instanceof IOException) throw (IOException)problem;
            sendProcessingError(problem, response);
     * Return the filter configuration object for this filter.
    public FilterConfig getFilterConfig() {
        return (this.filterConfig);
     * Set the filter configuration object for this filter.
     * @param filterConfig The filter configuration object
    public void setFilterConfig(FilterConfig filterConfig) {
        this.filterConfig = filterConfig;
     * Destroy method for this filter
    public void destroy() {
     * Init method for this filter
    public void init(FilterConfig filterConfig) {
        this.filterConfig = filterConfig;
        if (filterConfig != null) {
            if (debug) {
                log("TimeFilter:Initializing filter");
     * Return a String representation of this object.
    public String toString() {
        if (filterConfig == null) return ("TimeFilter()");
        StringBuffer sb = new StringBuffer("TimeFilter(");
        sb.append(filterConfig);
        sb.append(")");
        return (sb.toString());
    private void sendProcessingError(Throwable t, ServletResponse response) {
        String stackTrace = getStackTrace(t);
        if(stackTrace != null && !stackTrace.equals("")) {
            try {
                response.setContentType("text/html");
                PrintStream ps = new PrintStream(response.getOutputStream());
                PrintWriter pw = new PrintWriter(ps);
                pw.print("<html>\n<head>\n</head>\n<body>\n"); //NOI18N
                // PENDING! Localize this for next official release
                pw.print("<h1>The resource did not process correctly</h1>\n<pre>\n");
                pw.print(stackTrace);
                pw.print("</pre></body>\n</html>"); //NOI18N
                pw.close();
                ps.close();
                response.getOutputStream().close();;
            catch(Exception ex){ }
        else {
            try {
                PrintStream ps = new PrintStream(response.getOutputStream());
                t.printStackTrace(ps);
                ps.close();
                response.getOutputStream().close();;
            catch(Exception ex){ }
    public static String getStackTrace(Throwable t) {
        String stackTrace = null;
        try {
            StringWriter sw = new StringWriter();
            PrintWriter pw = new PrintWriter(sw);
            t.printStackTrace(pw);
            pw.close();
            sw.close();
            stackTrace = sw.getBuffer().toString();
        catch(Exception ex) {}
        return stackTrace;
    public void log(String msg) {
        filterConfig.getServletContext().log(msg);
}and in the web.xml :
   <filter>
        <filter-name>TimeFilter</filter-name>
        <filter-class>
            com.filter.TimeFilter
        </filter>
    <filter-mapping>
        <filter-name>TimeFilter</filter-name>
        <url-pattern>/services/*</url-pattern>
    </filter-mapping >