Java AWT applet

[VarunS Singh]

import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;
/*
<applet code="Parameter_Passing" width=300 height=80>
<param name = fontName value = Courier>
<param name = fontSize value = 18>
<param name = leading value = 2>
<param name = accountEnabled value = true>
</applet>

*/

public class Parameter_Passing extends Applet {
    String fontName;
    int fontSize;
    boolean active;
    float leading;

    @Override
    public void init() {
        setBackground(Color.YELLOW);
        setForeground(Color.blue);

    }
    @Override
    public void start(){
        
        String param = "Applet";
        fontName = getParameter("fontName");
            if(fontName == null)
              fontName = "Not Found";
            param = getParameter("fontSize");
            try{
                fontSize = Integer.parseInt(param);
            }catch(NumberFormatException e){
                fontSize = -1;
            }
            
            param = getParameter("leading");
            try{
                if(param!=null)
                leading = Float.valueOf(param).floatValue();
                else
                    leading=0;
            }catch(NumberFormatException e){
                leading = -1;
            }
            
            param = getParameter("accountEnabled");
            
                if(param!=null)
                    active=Boolean.valueOf(param).booleanValue();
            
    }
    @Override
    public void paint(Graphics g){
        g.drawString("Font Name is: "+fontName, 5, 10);
        g.drawString("Font Size is: "+fontSize, 5, 20);
        g.drawString("Leading: "+leading, 5, 30);
        g.drawString("Active: "+active, 5, 40);
    }

    
}

The output in applet window is :

Font Name is: Not Found
Font Size is:-1
Leading:0.0
Active: false


Why does it goes in The Exception in every block of code?

[Stephan van Hulst]

Because apparently whatever you're passing as fontSize, it's not an integer.

[Tim Moores]

It works fine for me using Java 8 on OS X. Offhand, I can't think of a reason why it wouldn't work elsewhere, since appletviewer would presumably work the same on all platforms.

As an aside, you should get in the habit of using double quotes around both names and values: <param name="fontName" value="Courier"> rather than <param name = fontName value = Courier>.

And, of course, applets are completely obsolete by now, so you should switch to learning standalone applications (or Java Web Start applications) instead, using JavaFX or Swing rather than AWT.

[Tony Docherty]

I suspect Tim is correct and it's because of the missing quotes.

Whilst Applets should work the same on all platforms the html that kicks off the Applet is read and processed by the browser and it may be that the browser you are using doesn't understand the param tag with missing quotes whereas Tim's browser has made some correct assumptions about what you intended to write. Can you make the changes he suggested and let us know if that has fixed the problem.

BTW Tim is also correct about Applets being obsolete, I suggest you don't spend too much time learning how to write code for them.

[Tim Moores]

I suspect Tim is correct and it's because of the missing quotes.

Actually, I tried the unchanged source code and it worked fine for me. So I can't even think of something to try instead.

[Tony Docherty]

Did you use AppletViewer or your browser?

[Tony Docherty]

I suppose there is always the unlikely possibility that the OP's system doesn't have the "Courier" font installed.

[Tim Moores]

I used appletviewer via "appletviewer Parameter_Passing.java".

[Norm Radder]

OP's system doesn't have the "Courier" font installed.

The code doesn't use the values of the parameters for anything but to display some text in the window.
This works for me using appletviewer,  ie  the values are read and shown in the window:

<applet code="Parameter_Passing" width=300 height=80>
<param name = fontName value = CourierXXX>
<param name = fontSize value = 18989898>
<param name = leading value = 2>
<param name = accountEnabled value = true>
</applet>

[VarunS Singh]

I changed as you suggested , but still not working....

[VarunS Singh]

I am using Netbeans, and as these Html code is written as comment , does it really matters , regarding the double coutes?

[Paul Clapham]

It never hurts to use well-formed HTML. And since your error messages from the original post tell me that your applet parameters are being ignored, it might be that using sloppy HTML is a problem. It might also be that something else is causing Netbeans to fail to notice the parameters.

[Tim Moores]

Maybe NetBeans works differently than appletviewer - did you try that one?

[VarunS Singh]

You are  rights guys it is actually working ok in Appletviewer