Re: what is wrong with File.createNewFile()

I've found a simple solution here:

http://enricogi.blogspot.com/2007/04/singleton-for-tomcat.html

I checked, and it seems to be the same object for all apps. A method
'showTime()'
returns the same value of hash key and creation time. I think that's
it. Many thanks to
everybody who helped me.

package lambdacommon;
//
import java.util.*;
//
public class Mutex {
//
long createdAt;
boolean isLocked;
static Mutex instance=new Mutex();
//
public static Mutex getInstance()
   {
   return instance;
   }
//
private Mutex()
   {
   isLocked=false;
   createdAt=new Date().getTime();
   }
//
public synchronized void lock()
   {
   try {
      if(isLocked) wait();
      }
   catch(InterruptedException ipx) {}
   isLocked=true;
   }
//
public synchronized void unlock()
   {
   if(isLocked)
      {
      isLocked=false;
      notify();
      }
   }
//
public String showTime()
   {
   return toString() + " created at "+createdAt;
   }
}