Hello,

I was wondering whether anyone could offer me some useful advice on learning Java 2 from Ivor Horton's book. I spent the last couple of weeks reading from chapters 1 to 4, and found it relatively easy to follow. I have also completed the exercises at the end of each chapter. But, when I came to chapter 5, I became somewhat disoriented and found it a little difficult to understand what is actually going on. Does chapter 5 touch on object-oriented programming? The exercise questions are a tremendous challenge and I could not even begin without having a look at the solutions which I downloaded from the Wrox web site. Is anyone encountering similar difficulties along their learning progress?

Thank you and I hope to hear from anyone of you soonest!

Sincerely,
Bobby

Hi Bobby,

Learning is frustrating but it is also very rewarding, and I'm sure that you will soon overcome your current difficulty; probably only yo be faced with another new challenge!

Java, as you know is an OO language and classes form the back bone of this, therefore you absolutely must understand most of Chapter Five before moving on with the rest of the book. It might even be helpful for you to postpone your Java efforts for a while and focus solely on learning OO concepts. Don't see this as a backwards step; too many people attempt to learn the syntax of Java without really understanding OO and as a consequence limit themselves in their use of the language. Get yourself a copy of "The Object Oriented Thought Process" by Matt Weisfeld, which is a great book and it is easily digested over a weekend... honestly. After reading this return to Chapter Five and it you will sail through it easily.

Have fun learning and make sure you ask any questions that you have. There are a couple of guys here who really know Java well (and no, I don't include myself in this category) and will bw able to help you out. If they can't help then I'll throw in my two pence worth.

Cheers

Martyn

Yes, chapter 5 takes more time than the other chapters.

I had problems getting my packages to work properly.
I put my packages as jar extensions in the: jre lib ext, but java did not find them.
Guess what: there was another java in my windows directory, and the classpath first called windows, then the JDK.
I placed the JDK first in the classpath, and now any class file anywhere can find these extension packages.

Took me 5 months to solve this. Brrr...

MY QUESTION would be:
does this particular problem put a limitation on the implementation of my laboriously written JAVA programs on other people's computers?
Suppose I have to tell my sister to adjust her AutoExec classpath, before my JAVA works. Brrr...

CheerZ~!
Frans

The way I have seen code distributed has been either compiled code packages in a .zip/.jar, or you include your source in the program's directory.

You don't have to have the JDK installed to run Java applications, all you actuall need is the JRE, which you can downlaod from Sun. The usual way of running your Java application would then be to specify the class path as part the Java command:

java -classpath /java/MyClasses/myclasses.jar utility.myapp.Cool

The Sun site contains a good tutorials about class paths, packages, and JARs.


Cheers

Martyn

Dear Martyn,

My sister has never even heard of classpaths, yet I feel I can assist her with one of my premium Java programs.
This should best be sent by email or downloaded from a website, and should run easily and by itself on her computer.

It should be a permanent program with a minimum of security restrictions, not an applet. But she don't mind giving me access, and she will click all the agree-access-yes-buttons.

It's a waste of time to explain her the classpath. But she will feel comfortable with a nice and easy GUI, prepared for the task it needs to perform.

How do I make life easier for her?
- Frans

Frans,

If your sister hasn't got the java's JRE installed on her PC then she will need to obtain this from the Sun website: http://wwws.sun.com/software/download/

I usually create a short cut on the desktop using javaw.exe, which contains all of the necessary information:

%windir%\System32\javaw.exe -cp c:\j2work ChangeLookAndFeel

I hope this helps

Martyn

Thanks Martyn, so the programmers have a tough time using the classpath, but our customers get the nice and clean GUI without the fuzz?

I am just testing the Java...

Frans
- at chapter 6 now

I am eaxctly in the same situation, and some syntax just strangely appears with no explanation. PErhaps this is just my frustration in being hard of thinking. Chapter 5 really is soo much more complex. I will get there I will get there I will get there

Yes I agree with you. Chapter 5 needs a lot of concentration. I found the book in general is rather more academic than other books in Java. It is a very good one, but I wished it could simplify the OOP concepts more. I would suggest "Java How To Program" by Deitel & Deitel.

Nawar