Java

RossouwDB11-Jul-11 1:18

11-Jul-11 1:18

I'm not sure I am following... (Java isn't my strongpoint.)

I don't set any environment variables myself, and I don't set any classpath myself either. I figured that the jar file (with the manifest and build file), would handle that for me.

Richard MacCutchan11-Jul-11 2:17

11-Jul-11 2:17

RossouwDB wrote:
I don't set any classpath myself

The -cp option followed by a list of .jar files is your classpath. You need to check that the class you are trying to invoke actually exists within one of your .jar files and is under the specified path (i.e. package and class).

The best things in life are not things.

RossouwDB11-Jul-11 2:25

11-Jul-11 2:25

Richard MacCutchan wrote:
-cp option followed by a list of .jar files is your classpath

crud, I knew but forgot that! Now I follow Blush | :O

The omniide is my "main" package, and the omniIDEApp is the entrypoint of my application. Everything is spelled correctly since I have even copied it as is from my Manifest file, but to no avail.

Here is the actual code for my entrypoint class:

/*
 * OmniIDEApp.java
 */

package omniide;

import org.jdesktop.application.Application;
import org.jdesktop.application.SingleFrameApplication;

/**
 * The main class of the application.
 */
public class OmniIDEApp extends SingleFrameApplication {

    /**
     * At startup create and show the main frame of the application.
     */
    @Override protected void startup() {
        show(new OmniIDEView(this));
    }

    /**
     * This method is to initialize the specified window by injecting resources.
     * Windows shown in our application come fully initialized from the GUI
     * builder, so this additional configuration is not needed.
     */
    @Override protected void configureWindow(java.awt.Window root) {
    }

    /**
     * A convenient static getter for the application instance.
     * @return the instance of OmniIDEApp
     */
    public static OmniIDEApp getApplication() {
        return Application.getInstance(OmniIDEApp.class);
    }

    /**
     * Main method launching the application.
     */
    public static void main(String[] args) {
        launch(OmniIDEApp.class, args);
    }
}

This code is generated by NetBeans when the project is created.

I am stumped as to the cause of this error! WTF | :WTF:

Richard MacCutchan11-Jul-11 2:41

11-Jul-11 2:41

Are you sure about the com. prefix in your class name:

java -cp OmniIDE.jar;lib\AbsoluteLayout.jar;lib\appframework-1.0.3.jar;lib\beansbinding-1.2.1.jar;lib\swing-layout-1.0.4.jar;lib\swing-worker-1.1.jar com.omniide.OmniIDEApp

[edit]You can check this by running the command jar -tvf against the jar file that contains (or should contain) your main class.[/edit]

[edit2]Or you could execute the .jar file directly by

java -cp lib\AbsoluteLayout.jar;lib\appframework-1.0.3.jar;lib\beansbinding-1.2.1.jar;lib\swing-layout-1.0.4.jar;lib\swing-worker-1.1.jar -jar OmniIDE.jar

assuming your main class is in the OmniIDE.jar file.
[/edit2]

The best things in life are not things.

RossouwDB11-Jul-11 2:43

11-Jul-11 2:43

I have tried omitting it, but still doesn't work.

Richard MacCutchan11-Jul-11 2:49

11-Jul-11 2:49

See my edits to my previous message.

The best things in life are not things.

RossouwDB11-Jul-11 2:58

11-Jul-11 2:58

Richard MacCutchan wrote:
running the command jar -tvf against the jar file that contains (or should contain) your main class

Confirms that com. is not needed, and that my main class is contained within the OmniIDE.jar file.

Richard MacCutchan wrote:
Or you could execute the .jar file directly

Does not work.

Richard MacCutchan11-Jul-11 3:07

11-Jul-11 3:07

RossouwDB wrote:
Does not work.

Really not a helpful definition of a problem!
What's the output of the jar -tvf command? Also what happens when you try with the -jar option? Please show exact commands and exact output in all cases.

PS: I do not use NetBeans but Eclipse, and I know there are some bits of framework stuff that NetBeans adds to your package so it may well be that you cannot run the final package outside of the NetBeans environment. However, why that would be so is anyone's guess.

The best things in life are not things.

RossouwDB11-Jul-11 3:12

11-Jul-11 3:12

I don't know how and why, but now everything is working!!

I was typing away, and doing a clean + build like I normally do,and when I tried to run it again, it bombarded me with error messages indicating that a lot of my packages could not be found!

Stumped, I cleaned and built it a couple of times, but failed miserably when I want to run it (really odd, since it was running successfully a couple of seconds ago.)

So, I located the "broken" package, and renamed it to the package NetBeans expected. Cleaned and built it, ran it - it worked.

So i though I might give executing the application a shot, and it worked!

It's really odd though, since NetBeans should have complained right from the start, but for some reason, it didn't. Confused | :confused:

Anyway, thanks for your help.

TorstenH.11-Jul-11 3:13

TorstenH.

11-Jul-11 3:13

Stop. that. NOW!

This is no simple Java homework that's not running.

Packaging and Deploying Desktop Java Applications with Netbeans[^]

Check that, READ IT and follow the instructions instead of burning money online.

regards Torsten
I never finish anyth...

Richard MacCutchan11-Jul-11 4:53

11-Jul-11 4:53

Sorry, what?

The best things in life are not things.

RossouwDB11-Jul-11 19:19

11-Jul-11 19:19

Wait, what???? Dude, you ok? Did I say this is homework?????

TorstenH.11-Jul-11 21:10

TorstenH.

11-Jul-11 21:10

This is no simple Java homework

Netbeans should provide a functionality to export your project in a proper way.
There is no need to build some strange stuff. That's time waisted.

regards Torsten
I never finish anyth...

RossouwDB11-Jul-11 21:25

11-Jul-11 21:25

TorstenH. wrote:
This is no simple Java homework

It's NOT HOMEWORK. It's a project I am working on...

TorstenH. wrote:
Netbeans should provide a functionality to export your project in a proper way.

Clearly it's not always working so well, but I would still use NetBeans.

TorstenH. wrote:
There is no need to build some strange stuff

Why not??? What isn't strange in live? Clearly you are.... So am I!

TorstenH. wrote:
That's time waisted

No, actually it's not! I have learned something from this entire experience, so I would not say it's time wasted!

Note:If you don't want to help people, and you want to attack them for some strange and peculiar reason, rather keep quiet! (Go read the guidelines: Insults, slap-downs and sarcasm aren't welcome. Let's work to help developers!)

Polymorphism problem in java..

TorstenH.12-Jul-11 0:03

TorstenH.

12-Jul-11 0:03

..That's what I said - this does not look like a simple homework-project that can be simply launched from the command line.

Why would you even want to work on the command line? All you're asking for is to run it outside of your IDE.

So I recommend to export the project in the given way and that's it. Netbeans will do what is is supposed to do - build your application.

No need to waste hours of time on fuzzy command line arguments. Better get a nice ice cream and watch Netbeans do the build Cool | :cool:

regards Torsten
I never finish anyth...

gateway239-Jul-11 6:21

gateway23

9-Jul-11 6:21

When we assign a subclass object to its superclass reference then the superclass reference can only access the methods that are in the superclass, it can't even the aceess its overridden methods in subclass.

if the above lines are true then how the following code can works ...

class a
{
int x;
void show()
{

System.out.println(x);

}
}

class b extends a
{
void show()
{
System.out.println("in subclass");
}

void show2()
{
System.out.println("in show2");
}

}

class Main
{
public static void main(String args[])
{
b bRef=new b();
a aRef=new b(); // why this line prints "in subclass". How a reference access the subclass?
aRef.show();

bRef.show2();

}

}

Richard MacCutchan10-Jul-11 5:43

10-Jul-11 5:43

See the note about implicit casting in this page[^] of the Java Tutorials.

Also please put your code between <pre> tags for proper formatting.

The best things in life are not things.

jschell10-Jul-11 12:53

jschell

10-Jul-11 12:53

gateway23 wrote:
a aRef=new b(); // why this line prints "in subclass". How a reference access the subclass?

A reference points to an object.
Your reference points to an object of type 'b'.

Shameel10-Jul-11 22:47

Shameel

10-Jul-11 22:47

gateway23 wrote:
a aRef=new b(); // why this line prints "in subclass". How a reference access
the subclass?

It is because eventhough you have declared aRef to be of class 'a', it acutally holds an instance of class 'b' at runtime. That is what Polymorphism is all about. That's not a problem, that's the expected behavior.

jschell12-Jul-11 10:11

jschell

12-Jul-11 10:11

It doesn't hold it. The heap holds it. It points to it.

Shameel12-Jul-11 19:10

Shameel

12-Jul-11 19:10

Well, that's what I meant. Don't read the word "holds" literally Smile | :)

Richard MacCutchan12-Jul-11 23:16

12-Jul-11 23:16

Shameel wrote:
Don't read the word "holds" literally

That is not the point. If you must give a technical answer then make sure it is accurate and clear. Remember, many of these questions are asked by people who do not have a lot of background knowledge or experience and rely on these answers to help them in their learning. The difference between "holds" and "points to" may be crucial to a new developer.

The best things in life are not things.

Shameel12-Jul-11 23:53

Shameel

12-Jul-11 23:53

You're right. I'll make sure I choose the right words to explain my answer. Thanks for pointing out.