/*
* Copyright (C) The Apache Software Foundation. All rights reserved.
*
* This software is published under the terms of the Apache Software
* License version 1.1, a copy of which has been included with this
* distribution in the LICENSE.txt file.
*/
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.SingleThreadModel;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.log4j.Logger;
import org.apache.log4j.LogManager;
import org.apache.log4j.Level;
/**
* A servlet used to dynamically adjust package logging levels
* while an application is running. NOTE: This servlet is
* only aware of pre-configured packages and packages that contain objects
* that have logged at least one message since application startup.
*
* @author Luther E. Birdzell
* @version 1.1
*/
public class Log4jControlServlet extends HttpServlet implements SingleThreadModel
{
/**
* The response content type: text/html
*/
public static final String CONTENT_TYPE = "text/html";
/**
* The root appender.
*/
public static final String ROOT = "Root";
/**
* The name of the class / package.
*/
public static final String CLASS = "CLASS";
/**
* The logging level.
*/
public static final String PRIORITY = "PRIORITY";
/**
* Print the status of all current Loggers and
* an option to change their respective logging levels.
*
* @param request a HttpServletRequest value
* @param response a HttpServletResponse value
* @exception ServletException if an error occurs
* @exception IOException if an error occurs
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
response.setContentType(CONTENT_TYPE);
PrintWriter out = response.getWriter();
List loggers = getSortedLoggers();
Logger logger = null;
String loggerName = null;
int loggerNum = 0;
// print title and header
out.println("Log4J Control Console" +
"Log4J Control Console
");
out.println("Refresh
");
out.println("");
out.println("");
out.println("| Class | ");
out.println("Priority | ");
out.println("
");
// print the root Logger
displayLogger(out, Logger.getRootLogger(), loggerNum++, request);
// print the rest of the loggers
Iterator ii = loggers.iterator();
while( ii.hasNext() )
{
displayLogger(out, (Logger) ii.next(), loggerNum++, request);
}
out.println("
");
out.println("* "+
"Inherits Priority From Parent.
");
out.println("Refresh
");
// print set options
out.println("");
out.println("");
out.flush();
out.close();
}
/**
* Change a Logger's level, then call doGet
* to refresh the page.
*
* @param request a HttpServletRequest value
* @param response a HttpServletResponse value
* @exception ServletException if an error occurs
* @exception java.io.IOException if an error occurs
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
{
String className = (String) request.getParameter(CLASS);
String priority = (String) request.getParameter(PRIORITY);
if (className != null)
{
setClass(className, priority);
}
doGet(request, response);
}
// print a Logger and its current level
private void displayLogger(PrintWriter out, Logger logger,
int row, HttpServletRequest request)
{
String color = null;
String loggerName = (logger.getName().equals("") ? ROOT : logger.getName());
color = (row%2 == 1) ? "#E1E1E1" : "#FBFBFB";
out.println("");
out.println("| " +
loggerName + " | ");
out.println("" +
( (logger.getLevel() == null) ? logger.getEffectiveLevel().toString() +
"*" : logger.getLevel().toString()) + " | ");
out.println("
");
}
// set a logger's level
private synchronized String setClass(String className, String level)
{
Logger logger = null;
String message = null;
try
{
logger = (className.equals(ROOT)) ? logger.getRootLogger() :
logger.getLogger(className);
logger.setLevel(Level.toLevel(level));
}
catch (Exception e)
{
System.out.println("ERROR Setting LOG4J Logger:" + e);
}
return "Message Set For " + (logger.getName().equals("") ? ROOT : logger.getName());
}
// get a sorted list of all current loggers
private List getSortedLoggers()
{
Logger logger = null;
Enumeration enum = LogManager.getCurrentLoggers();
Comparator comp = new LoggerComparator();
ArrayList list = new ArrayList();
// Add all current loggers to the list
while(enum.hasMoreElements())
{
list.add(enum.nextElement());
}
// sort the loggers
Collections.sort(list, comp);
return list;
}
/**
* Compare the names of two Loggers. Used
* for sorting.
*/
private class LoggerComparator implements Comparator
{
/**
* Compare the names of two Loggers.
*
* @param o1 an Object value
* @param o2 an Object value
* @return an int value
*/
public int compare(Object o1, Object o2)
{
Logger logger1 = (Logger) o1;
Logger logger2 = (Logger) o2;;
String logger1Name = null;
String logger2Name = null;
if ( logger1 != null )
logger1Name = (logger1.getName().equals("") ? ROOT : logger1.getName());
if ( logger2 != null )
logger2Name = (logger2.getName().equals("") ? ROOT : logger2.getName());
return logger1Name.compareTo(logger2Name);
}
/**
* Return true if the Object is a
* LoggerComparator instance.
*
*
* @param o an Object value
* @return a boolean value
*/
public boolean equals(Object o)
{
if (o instanceof LoggerComparator)
return true;
else
return false;
}
}
}//EOF