Thread: How to referenc a class file. using only notepad and run cmd.

You need to tell Java what the classpath is. Recommended reading: Setting the class path

Dear the WorkMan:

Ok so i see:

C : > sdkTool -classpath classpath1;classpath2...

But I am confused, in Notepad, where I am programming, and assuming that the base directories do not match.

How will the program know that I am creating a link (class path) to the class I want to reference, when I write:

C : > sdkTool -classpath classpath1;classpath2...

in the Command Prompt?

If I could see an example I could work it out my self.

Cheers.

SpacedOut Monkey.

You don't "tell" notepad anything about the classpath. You tell the compiler and the JRE about the classpath. You do that be specifying the classpath as an argument when you compile and run your program.

Both the javac and the java commands have commandline options to specify the classpath to use. Look at the doc for those commands to get the correct syntax.

Dear Workman:

QUESTIONS AT END OF POST

My problem is that I do not have a good understanding of the computer.

I a case like this you need to let me know that I need to deal with the "Environmental Variables" otherwise I am just floundering.

In the Environmental Variables, in the UserVariables section I have entered the:
Variable Name: Classpath
Variable value: .;C:\Users\Kevin\Documents\JavaNotepad\Bootclasspa th.class;C:\Users\Kevin\Documents\JavaNotepad\Pres entStudy

The directory to the class I am calling is in JavaNotepad file.
The class is called Bootclasspath, and I am calling it as "Bootclasspath.class".

The place from where I am calling it is:
C:\Users\Kevin\Documents\JavaNotepad\PresentStudy
The program I am working on is FixChap5.java, which is located in the file "PresentStudy"

This is not working, the error I am getting is. "package Bootclasspath does not exist."
FixChap5.java calls the class "Bootclasspath", and gets the error message "package Bootclasspath does not exist.".

So I think the problem is with the ending of each of the two lines of classpath statement
.:
I sort of understand the above line indicates look in the current folder.

C:\Users\Kevin\Documents\JavaNotepad\Bootclasspath .class;

Should the above classpath end in the JavaNotepad folder name, or Bootclasspath.java, or should Bootclasspath be in a jar or zip file?

C:\Users\Kevin\Documents\JavaNotepad\PresentStudy

Is the above classpath correct or should it contain the file name (FixChap5) with a java or class or zip or jar file ending?

I started my computer a lot, put this comment in caps and did not realize that people where interpreting it as shouting, sorry. Note the cheers after, that was the intended tone. Crap.
Cheers.

SpaceMonkey.

P.S. Look at the views over the last two day, you lot need to put up a tutorial on this one because it is not covered well anywhere. Also for us not using eclips, just notepad, it is vital.

Originally Posted by SPACE MONKEY

I a case like this you need to let me know that I need to deal with the "Environmental Variables" otherwise I am just floundering.

Word to the wise- don't tell somebody who is helping you, for free, in their spare time, what they "need" to do. It just comes off as ungrateful, which I don't think you actually intend.

Originally Posted by SPACE MONKEY

In the Environmental Variables, in the UserVariables section I have entered the:
Variable Name: Classpath
Variable value: .;C:\Users\Kevin\Documents\JavaNotepad\Bootclasspa th.class;C:\Users\Kevin\Documents\JavaNotepad\Pres entStudy

Please read the tutorial I linked to you. It contains an explanation of what you're doing wrong here.

Originally Posted by SPACE MONKEY

Should the above classpath end in the JavaNotepad folder name, or Bootclasspath.java, or should Bootclasspath be in a jar or zip file?
Is the above classpath correct or should it contain the file name (FixChap5) with a java or class or zip or jar file ending?

The tutorial I linked you contains the answer to this question.

Originally Posted by SPACE MONKEY

.S. Look at the views over the last two day, you lot need to put up a tutorial on this one because it is not covered well anywhere. Also for us not using eclips, just notepad, it is vital.

Again, telling "you lot" what we "need" to do is pretty rude. I already linked you a tutorial that you seem to be misunderstanding, plus there are tons of resources out there on this exact issue. Do a google search of "setting Java classpath" or something before you declare that we NEED to put up a tutorial because it's not covered ANYWHERE.

Try doing a more simple exercise without packages so you will not have to worry about classpath just yet. Remove the package statement from all the source and put all the .java files in the same folder. Also remove any import statements that refer to any of your packages.
When all the source compiles and executes with no errors, then work on moving one of the classes to a package.

Dear Norm:


I do not have any packages. I need to look up packages?
The whole point is that I do not understand how to reference classes and thus I want to know. It is integral to java so I need to understand.

If everything is in one folder you do not need import statements or classpath settings. When you get a working group of classes THEN work on the next step: putting a class in a package and using an import statement and classpath. Take one small step from a known working version.

Do you have a set of classes that compile and execute without packages, import statements or classpath settings? You need to start from a known working position.

Can you list the names of the source files you are working with?

onto step 2.

Define what you want to do for step 2.

Dear Norm:

Norm sorry for not answering your question I ran out of time.

For point two I wanted to know how to set the class path so I could call a method from a class that is not in the same base folder as the calling class.

First class

 
import java.util.Scanner;
import java.lang.Math;
public class FixChap5
{
public static void main(String[] args)
{
Scanner keyboard = new Scanner(System.in);
	int x = 1;
	boolean b = false;
	do
	{
		if ( x%2 == 0)
	 		b = true;
		else
			b = false;
 
		x++;
	}
	while ((!b )|| (x < 7));
	System.out.println(" x = " + x);
	Bootclasspath.callBootClass();
}}

Second class

public class Bootclasspath {
 
public static void callBootClass()
	{
	System.out.println(System.getProperty("sun.boot.class.path"));
	}
    public static void main(String[] args) {
    callBootClass();
    }
}

so the classes are real simple, I just want to understand how to link them. Then I go onto packages.

Cheers.

SpaceMonkey

If the .java and the .class files are in the same folder, there should not be a problem.
Why is the import Bootclasspath.*; statement there? Using that entails classpath and folder usages that you claim you are not using.
Remove it.

I am trying to do this one step at a time.
When you have the two class files so that they compile and execute using only one folder and no import statement, we'll move one step to using a package.

Do your two .java files compile and execute?

Dear Norm:

Done, I edited my code in the post 3 or 4 back and it works fine. I simply remove the import Bootclasspath.*; and everything is fine.

The two .java files compile and execute when in the same base file.

Forgive me if this is impossible or unwise, but I am not looking to learn Packages unless it is a prerequisite for learning to connect two classes.

I just want to know how to set the class path. Of course if I need to know Packages right now, then thanks for keeping me on the right path.

Thanks.

SpaceMonkey

Now to the use of package and import statements:
create a folder: package1 in the folder which the FixChap.java is in.
Move the Bootclasspath files to that folder.
Add a package package1; statement to the Bootclasspath.java file.
Compile it.
Edit the FixChap5.java and add import Bootclasspath.*; to it
compile and execute it. (the default classpath should be the folder with these three things in it: the FixChap5 files and the package1 folder.)

I did not say to execute the Bootclasspath program. That will require setting the classpath.
You were to execute the FixChap5 program the same way you did it before.

Please post the full text of the error messages.