inside my generic servlet I get this error when I call this method:
'session.getAttribute' command (line 36):
java.lang.NullPointerException
    at java.util.Hashtable.get(Hashtable.java:336)

Is it *really* true that creating an object closer to where it will be
used by the code, rather than creating it and setting it to null,
makes a noticeable difference performance-wise?
What is the best practice with respect to this?

I get this error and have now spent a day to figure out what causes
it. Anyone an idea?
Thanks in advance for your help.
Michael

Here it is, easily browsable :
http://d.cr.free.fr/wsqualitycheckerjavasyntaxe_html.html
Thanks to "The Java Language Specification", Third Edition (Addison
Wesley, May 2005) chapter 18 reference, with some small modifications.

I did post this on the sun forum with out too much help. I am assuming
I shall be lucky enough to get some here.
Since I am clueless on how I wish to do it, I do not really have
anything that I have done.

I have this code:
public Boolean getValue(ItemAttributeSource source) {
    Currency c = FIXED_SHIPPING_CHARGE.getValue(source);
    return (c != null ? c.compareTo(c.getUnit().ZERO_VALUE) > 0 :

I want to give a SCJP certification.
But now SCJP 1.6 is latest and I have prepared for SCJP 1.5.
Can anyone tell me which will be best?
If possible provide some useful links.

The javax.xml and javax.xml.stream packages have some classes that look  
very useful for writing and reading XML (the latter package especially).  
Unfortunately, as near as I can tell they are for the most part only  
supported in Java 6 and later.  The few things that are ...

If an applet comprises say 40 classes in 4 separate JARs, is Java "smart"
enough to only download the individual class files from within each JAR as
they are first accessed or will accessing one class in a JAR cause a
download of the entire JAR before methods in that class can be ...

When I call
system('/mnt/hd9/a.out');
the prog sucessfully print a message to web browser. (a.out is an object
file compiled from a C file).

I was trying to profile the following piece of code using NetBeans:
public static void main(String[] args)
{
   Map<String, String> map = new HashMap<String, String>();

How to extract substring with regexp when we have start and end for
substring?
For example I want to find what is between "abc" and "xyz" in the
String.