I have a constructor that takes a String argument. I'd like to throw an
exception if the constructor is invoked with a null argument, but I'm
not sure which instruction I should use.
NullPointerException is technically accurate, since it is a null

reference
http://java.sun.com/javase/6/docs/api/java/util/Random.html#nextInt(int)
do {
      bits = next(31);

i was arguing with my manager about whether it's better to throw
exception from a service that im developing or to give the user
returned value. My supporting points are:
1-thowing exception is much mostly than returned value in term of

My task is : Archieving log file before logging rotation (define
logfile size ,number)
only can copy file but append file.
or someone told how to append log file by using FileHandler or other

1) With dynamic polymorphism, calls to actual methods are resolved at
run time. So why is that so important?  Why is that so much better
than letting the compiler figure out which version of method to call
( based on the type of object being referred by reference variable )?

My day job is programming in modern statically-typed functional programming
languages like OCaml and F#. In my spare time in the evenings I like to
expand my mind by learning about really different languages like Java.
Tonight, I watched a fascinating lecture by Joshua Bloch called ...

class A
{
   public int showMe() { System.out.println("A"); }
}

I'm doing some work on a large software project that has mutual
dependencies - EG, the build of jar A depends on jar B's interface, and
the build  of jar B depends on jar A's interface.
It seems these dependencies could be resolved nicely if we were to build

Hello java guys
i'm writing chat software ,data send from client to server and server
response to client
so i need to send many data formats such as voice, text based i need

hi...
I am a final yr engineering student going my project currently. My
topic is "media based monitoring system using smart phones". We have
decided to use JMF in our project. Can you suggest any good books for

Urgent please.... how to compress a single jpeg image frame to
maintain  quality and  half of it's original storage size using java
source code.........

Hello guys. I have been trying hard to load an Image but with no luck.
Basically I want an application that can take an Image (jpeg) from a
specified location on my disk and show it. I get confused with all the
canvas, paint, render ,update stuff that makes the task seam very

I know the easy answer is to restart the server, but I can't do that
with my hosting company.,,
My issue is that I am updating a servlet on my web hosting company
(godaddy), and it is supposed to update in 45 seconds from when it is

I am about to start writing a UI application and am thinking about
writing it in SWT. I have experience with Swing but never used SWT. I
thought it might be good to get to know another technology. I am
writing the application for a windows machine so portability is not a

I have a java applet that scrolls through some pictures that are found
in the same directory as the java code. When I run the applet from
inside of my compiler everything seems to work fine. However, when I
insert the applet into html code using the applet tag or the object