com.javaranch.common
Class LogServlet

java.lang.Object
  |
  +--HttpServlet
        |
        +--com.javaranch.common.LogServlet

Direct Known Subclasses:

ActionServlet, ObjectServlet

public abstract class LogServlet

extends HttpServlet

Used for tracking events in a Servlet.

Log messages are sent to a logging object that defaults to being turned off. Activating the servlet via a web browser gives you access to activate logging for debugging purposes.

Override this class and call logMessage() to add messages to the log.

Override doGet() to disable the error logging feature for production.

Example:

     public class EchoServlet extends LogServlet
     {

         public void doPost( PrintWriter out , CastMap parms )
         {
             String text = parms.getString( "text" );
             if ( usable( text )  )
             {
                 for ( int i = 0 ; i < 100 ; i++ )
                 {
                     out.println( text + "<br>" );
                 }
             }
             else
             {
                 reportProblem( out , "invalid parameters" );
             }
         }

     }


 

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Copyright (c) 1999-2004 Paul Wheaton

Copyright (c) 1999-2000 EarthWatch, Inc.

You are welcome to do whatever you want to with this source file provided that you maintain this comment fragment (between the dashed lines). Modify it, change the package name, change the class name ... personal or business use ... sell it, share it ... add a copyright for the portions you add ...

My goal in giving this away and maintaining the copyright is to hopefully direct developers back to JavaRanch.

I originally developed this class while working as a contractor at EarthWatch, Inc. in Longmont, Colorado. They gave me permission to distribute this code this way provided that their message would also be carried along. Their message is that they hire Java programmers and would like you to consider working with them. I have to say that my experience with them was first rate and I would encourage engineers to work there. Check out their web site at http://www.digitalglobe.com.

The original source can be found at JavaRanch

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Author:

Paul Wheaton

See Also:

Serialized Form

Field Summary

protected int	getCount increment this if you override the traditional doGet()
protected int	postCount increment this if you override the traditional doPost()

Constructor Summary

LogServlet()

Method Summary

protected void	checkConsoleLogging() Call this as the first thing you do if you override the traditional doGet() or doPost().
void	debugReport(java.io.PrintWriter out) Override this if you have more to say in the GET debug information.
protected void	doGet(java.io.PrintWriter out, CastMap parameters) if you need doGet, override this instead of the normal doGet.
protected void	doPost(java.io.PrintWriter out, CastMap parameters) if you need doPost(), override this instead of the normal doPost().
void	emailMessage(java.io.PrintWriter out, java.lang.String s) E-mail a message to the admin, send it to the user and add it to the log.
void	emailMessage(java.lang.String s) E-mail a message to the admin and add the same message to the log.
void	logMessage(java.lang.String s) Add a message to the log.
protected void	reportProblem(java.io.PrintWriter out, java.lang.String message) This convenience method sends the message to the log and sends it to out.
static void	setAccessParameterName(java.lang.String accessParameterName)
static void	setAccessParameterValue(java.lang.String accessParameterValue)
protected void	setLogConsole(boolean on) Messages are sent to STDOUT so they can be tracked in the servlet server logs.
protected void	setLogMemory(boolean on) Messages are logged to memory so they can be viewed by a GET command.
protected boolean	usable(java.lang.String s) Deprecated. use Str.usable() instead

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

postCount

protected int postCount

increment this if you override the traditional doPost()

getCount

protected int getCount

increment this if you override the traditional doGet()

Constructor Detail

LogServlet

public LogServlet()

Method Detail

setAccessParameterName

public static void setAccessParameterName(java.lang.String accessParameterName)

setAccessParameterValue

public static void setAccessParameterValue(java.lang.String accessParameterValue)

setLogMemory

protected void setLogMemory(boolean on)

Messages are logged to memory so they can be viewed by a GET command.

setLogConsole

protected void setLogConsole(boolean on)

Messages are sent to STDOUT so they can be tracked in the servlet server logs.

checkConsoleLogging

protected void checkConsoleLogging()

Call this as the first thing you do if you override the traditional doGet() or doPost().

This makes sure that console logging is turned off if it is no longer desired.

logMessage

public void logMessage(java.lang.String s)

Add a message to the log.

reportProblem

protected void reportProblem(java.io.PrintWriter out,
                             java.lang.String message)

This convenience method sends the message to the log and sends it to out.

usable

protected boolean usable(java.lang.String s)

Deprecated. use Str.usable() instead

Convenience method - returns true if the string is not null and not empty.

emailMessage

public void emailMessage(java.lang.String s)

E-mail a message to the admin and add the same message to the log.

emailMessage

public void emailMessage(java.io.PrintWriter out,
                         java.lang.String s)

E-mail a message to the admin, send it to the user and add it to the log.

debugReport

public void debugReport(java.io.PrintWriter out)

Override this if you have more to say in the GET debug information.

doPost

protected void doPost(java.io.PrintWriter out,
                      CastMap parameters)

if you need doPost(), override this instead of the normal doPost().

Parameters:

out - use this to send HTML to the browser.

parameters - all of the parameters sent to the servlet are stored in this hash table.

doGet

protected void doGet(java.io.PrintWriter out,
                     CastMap parameters)

if you need doGet, override this instead of the normal doGet.

Parameters:

out - use this to send HTML to the browser.

parameters - all of the parameters sent to the servlet are stored in this hash table.