Applet use with HTML// also appletviewer question

Question

I am new to the language. I am trying to start an applet in a folder that I created on my hard drive(C:). I have included the following code in my HTML in my folder.
<applet code="NotHelloWorldApplet.class"
width= "300" height= "300">
</applet>
I have already compiled the program; I have the net beans 1_4_2 compiler, and it has compiled without errors.
The code is :
import java.awt.*;
import javax.swing.*;
public class NotHelloWorldApplet extends JApplet
public void init()
Container contentPane = getContentPane();
JLabel label = new JLabel("Not a Hello, World applet",
SwingConstants.CENTER);
contentPane.add(label);
I have also downloaded Plug-In; if that means anything. When I open the HTML folder a grey box appears; then at the bottom of the window it says that it cannot find the file; even though the file exists(I have looked with the file finder and it is in my file directory). Is it in the wrong directory? How does the file folder in windows know how to run and execute a java program with the preceding HTML code. This is the method explained in a current text book that I am using. It tells me to
1. to compile the source code into class files.
I used the compiler and I successfully created a .class file, (obviously the title of the program is .java program, but the class file does exist.
Then 2. add the above code in the HTML program(which I did).
I would like to get applets running but do not know how to correct this problem. Is there more HTML code that I need to run a java program in the folder's code.
Also, the textbook I am using tells me to preview the applet with appletviewer. I loaded the appletviewer into the editing screen and it is a bunch of hieroglyphics. One of two possible problems are that it is not included with the Net_Beans_1.4.2(it was from another download) or the download was contaminated. Anyway, the question I have is; is appletviewer an application that is viable with Net_Beans_1.4.2 and if it is from where and how do I run or execute it to preview my applets before I run them inside an HTML document.
Derk_the_Zeeman
[email protected]

Answer 1

Sounds to me like you're having trouble with NetBeans, not applets or appletviewer. You should consult their docs on how to access their version of appletviewer.
It also sounds to me like you're using the book CoreJava by Horstmann/Cornell.
Notice that they package TextPad with their book. This is for a good reason. It is very easy to be suckered into thinking you know what is going on when you have an IDE that does stuff for you. I know. I programmed in VB for a while, and I thought I knew how to do Windows programming. But I didn't. VB was doing all the work for me while I was drawing boxes on the screen and patting myself on the back. It took several major blows to the ego before I found out that all I really knew how to do was how to draw a bunch of silly boxes.
New programmers should start out with a text editor. They get a better feel of what is going on.
I don't know how NetBeans works -- even now I prefer TextPad over any IDE I've tried. But appletviewer works in the same way the java and javac command works, except that the argument it takes is the name of the html file which contains those applet tags (<APPLET>).
I have some thoughts on your problem:
1) you have an html file somewhere, but you don't know where. It is somehow created in a "window". the tag
applet code="NotHelloWorldApplet.class"
means "look in this directory for the class NotHelloWorldApplet.class" So if the html file you have created is not in this directory, how will appletviewer (or NetBean equivalent) know where it is? (hence, "class not found")
2) Is this correct? You have downloaded the plug-in for your browsers, but you didn't try using your browsers to see the applet?
If so, try this: go to IE or Netscape (or whatever you favorite browser is) and try in IE File-->Open and hit the browse button, or in Netscape File--> Open File
Next, try to find the file "NotHelloWorldApplet.html" or whatever it is you called the "window". Open the html file.
If it doesn't work, check to see if the html file is in the same directory as the class file (repeat procedure, but now look at files of type "All")
3) You can make an html file with notepad. You don't need anything special. Just type in the html code that Horstmann/Cornell include into notepad and save as an html.
Does this help?
:) jen