Vasile's Java FAQ

1. What tools do you use for Java programming?
2. If I mail you, when I can expect to get a reply?
3. How do you support your programs?
4. Can you adapt to my needs one of your Java programs?
5. Can you make a special development for my webserver?
6. Can I rename .class files I get from your site?
7. Why your programs are still developped for Java 1.02 ?
8. On what browser(JVM) and OS are working your programs?
9. What people without Java-enabled browsers will see instead of the applets?
10. How to do if I want to put the .class in another directory than where is located my HTML file?
11. Your applets are good, but, really, do you think somebody will buy them?
12. How do I make an applet working on my site?
13. Installing Java applets (detailed instructions)
14. How do you compile a .java file into a .class file?
15. When extracting the files from the zip archive, they have incorrect names. How to correct this?
16. Do I need to upload .java files to the server?

1. What tools do you use for Java programming?
   For all Java programmig I use Sun's JDK 1.02 for Win32. It includes the compiler and runtime environment (both for applets and programs), in command-line mode.
   For editing I use GNU Emacs for Win32. Some months ago I used Kawa - a small IDE for Java programming. Kawa has all basic features and is better than most commercial products. Also, they offer a free of charge license for students. Good for a Java beginner.
   For a closer look in Java API I recommend DippyBird, which offers a WinHelp version of all the API. Of course, you can always use Sun's original HTML version of Java documentation.

2. If I mail you, when I can expect to get a reply?
   Normally, I answer all the mails I get within 24 hours (it depends of your the time lag with Europe). If you are in Europe, there is great chance you get a reply within 2 hours.

3. How do you support your programs?
   The support is e-mail based, worldwide. I try to answer all requests as fast as possible.
   You can also call me, but it far from the best way. Don't forget the time lag with Europe, where the time is GMT+1.

4. Can you adapt to my needs one of your Java programs?
   Yes, I can adapt to your needs one of my programs. Small adapts are free. For other special developments see special development question.

5. Can you make a special development for my webserver?
   Yes, I can make special delelopments for you. It can be a Java, Perl, database, Internet/Intranet development. Of course, the price depends of the worktime spended on your project (and it's more than 12 or 27 USD).

6. Can I rename .class files I get from your site?
   No, you cannot rename them. Renaming a .class file will cause a "java format error". The only way to change the name of a Java class is to get the source code and to recompile it.
   Java is even case sensitive: WooK.class is not the same as Wook.class or Wook.CLASS. The verification is done by the Java Virtual Machine which will not execute a renamed class.

7. Why your programs are still developped for Java 1.02 ?
   When I started developping in Java (end of 1996), Java 1.02 was stable enough to be used in all environments (applets and standalone programs). And I still use this version of JDK from Sun.
   Java 1.1 was adopted very painfully by the browsers, and this with a lot of incompatibilities (which are still here).
   Also, previous versions of browsers (Netscape 2.0-3.0, Internet Explorer 3.0) use Java 1.02 only.
   So, if you want to make and use now Java applets, you have to use JDK 1.02.

8. On what browser(JVM) and OS are working your programs?
   Theoreticaly, Java must be "write once, run anywhere", but practicaly this is far from being true.
   I tested my programs and they are working well on Netscape 2.0 - 3.0 - 4.5, Internet Explorer 3.0 - 4.0, appletviewer (JDK 1.02) on Windows 95. I tested some of them on Linux, Solaris, MacOS (with Netscape 3.0).
   You can also take a look at the information gathered by VasSpyApplet about the browsers and the OS of the visitors of my site.

9. What people without Java-enabled browsers will see instead of the applets?
   People without Java-enabled browsers (Netscape 1.0 or if Java was disabled) will not see your applets. If you want they see something else, you can place an alternative text, or some html code like this:
   <APPLET CODE="WooK.class" WIDTH=10 HEIGHT=10>
   <PARAM NAME=par1 VALUE="value1">
   HERE YOUR ALTERNATIVE TEXT OR HTML
   </APPLET>
   

10. How to do if I want to put the .class in another directory than where is located my HTML file?
    If you want to load .class files from another directory, just use the codebase tag. For example, instead of <APPLET CODE="WooK.class" WIDTH=10 HEIGHT=10> you can put <APPLET CODEBASE="your_directory" CODE="WooK.class" WIDTH=10 HEIGHT=10>.
    You can even use the applet from other servers than yours: <APPLET CODEBASE="http://your_server/your_directory" CODE="WooK.class" WIDTH=10 HEIGHT=10>.

11. Your applets are good, but, really, do you think somebody will buy them?
    Yes, every month I get some dozens of paid registrations and some free registrations (mostly for persons from Eastern Europe). I think it's not so bad.

12. How do I make an applet working on my site?
    In short: you need to download the applet, install it on your webserver and configure the web page by calling the applet with a <APPLET> tag. If it's not clear enough, please read detailed instructions.

13. Installing Java applets (detailed instructions)
    Java applets are supported by Netscape 2.0 or better, Internet Explorer 3.0 or better, and some other browsers (HotJava, Opera with a plug-in..).
    Java is different from JavaScript: Java applets are made by .class files and are more powerful than JavaScript. You cannot use .java files directly or paste them in .html files. So there's no need to put .java files on your webservers.
    Don't forget that .class files must not be renamed and even the case is important.

    To install applets, you have simply to do this:

    1. Extract the files from .zip archive you downloaded from the webserver.
    2. Copy the .class files to same directory as the HTML document to which you want to add the applet. Don't copy to the server .java files!
    3. Add the <APPLET> tag to the HTML document, as explained in applet's documentation. Some html editors don't permit this or have strange standards, in this case save the .html file, then edit it with notepad or another simple text editor, and add manually the <APPLET> tag.
    4. Upload .html and .class files to your webserver as usual. When using FTP, .class files must be uploaded in binary mode, not in ASCII (text) mode.

14. How do you compile a .java file into a .class file?
    You have to use a Java compiler.
    The best way is to use Sun's JDK (Java Development Kit). Sun is creator of Java, so their compilers are the most used. Also their compiler is free, but it's running only on Win32 (Win95-98-NT) and Solaris. Their site is http://www.sunsoft.com
    For compatibility reasons, I strongly advice to use JDK 1.02 (not later version).

15. When extracting the files from the zip archive, they have incorrect names. How to correct this?
    Your zip extractor has a problem. You can use EasyZip2000, a good freeware extractor, which you can find at http://members.xoom.com/ipsoft.

16. Do I need to upload .java files to the server?
    You need to upload to the webserver just the .class files. Don't copy to the server .java files!