I have been trying to get a simple java program working in Linux but I cant seem to get it working.

Its the simple Hello World program. I can get it to compile in JavaByte code but when running it nothing appears at the command prompt.

Here is the code:

class Hello
{

public static void main(String[] args )
{
System.out.print("Hello world!");
}
}

No error messages at all. I compile ( javac Hello.java), then run (java Hello) and nothing happens.

Is it me? I do have the sun jdk installed into /usr/local. Any thoughts?

i'm pretty sure i'm wrong but java MIGHT be cos youv'e used print not println. i know C doesn't print the lin until you insert a newline, but other than that i can't suggest anything. I would've tried it, but i've not got java installed at the moment...

ahh bobbins... yes i have.. no the code works fine at least, no problems there... tired... time for bed...

maybe the standard out isn't set up ...? try redirecting the output to a file.

I should be able to use print, well I can at uni. Will do what you suggested when I get back home. I need some sort of tutorial on setting up Java in Linux. Do you know of anywhere?

Thanks for the reply

The output recorded in the file is Hello World!

But this never appears at the prompt?

well, i'd have to presume there's somethign up with your streams somewhere along the line, but i'd have no idea how to fix it!

tried just running it in tty1 or something?

Problem solved. You were right about println, print didn't come up wiv anything, but println did. Also, print worked for tty1, but not how I had imagined it to.

Thanks for the help, now to many hours coding!

The print() method on it's own does not print to the screen unless the System.out.flush() method is invoked afterwards. The println() method effectively does it for you, so this would also work:

class Hello
{

public static void main(String[] args )
{
System.out.print("Hello world!");
System.out.flush();
}
}

well, i found just print DID work, does java flush everything before killing the VM then by default?

I still get the same problem with print.

The print works, but the bash prompt ends up right after it and after pressing any key the text disappears and the prompt takes its place!

Also, I want to use another class in my program, and was told to stick in the same directory to be able to access it. Is this correct as the compile doesn't work, saying it can't find the class.

Maybe a "\n" (newline) at the end of the print would clear the first problem up. As far as accessing another class, as with everything, Java is case sensitive, so make sure that you have specified the name exactly right. If you start compiling your first class, it should check the dependencies and compile the class it is including. To be sure you could compile the second class first, sort out any errors, and then compile your first class.
If your program splits into loads of classes though, you can trust the dependency checker to sort everything out
(the java compiler is ALWAYS right )

HTH

glj

It may have helped had I actually compiled the classes in the first place! They were in .java when I downloaded them. Doh!

Cheers for the advice.

now forgive me if i take u guys back ,but i am new to linux and its been pretty difficult coming to terms with it.now my problem is simlpe even if it sounds dull ,i am desperate to get java running on my redhat linux system .it was installed by someone else and i dont know where it is but it is installed .so how do i run it . the only text editor i have is emacs ,how do i use it to key in my programs or could i use pico.thirdly i downloaded an online version of thinking in java ,how do i unzip it.i am desperate and will really appreciate step by step elementary answers .please i await your accelerated response .i have read a lot of your posts and you guys have been magnificent, please help get me started.