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Thread: Java applet

  1. #1
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    Default Java applet

    Hello,
    I have a problem when I try to implement java applet to a web page. Web page keeps saying :
    NoClassDefFoundError. Can anyone help me with this?

    here is a html code:

    HTML Code:
    <header>
    
    <body>
    
    <applet code = "Calculator.class" width=300 height=250 />
    
    </body>
    
    </header>


  2. #2
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    Default Re: Java applet

    Don't add the .class part. It's like when you run a Java class file, you don't say "java ClassName.class" - you just do "java ClassName".

    Recommended reading: Deploying With the Applet Tag (The Java™ Tutorials > Deployment > Java Applets)
    Useful links: How to Ask Questions the Smart Way | Use Code Tags | Java Tutorials
    Static Void Games - Play indie games, learn from game tutorials and source code, upload your own games!

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    ikocijan (June 29th, 2012)

  4. #3
    Super Moderator Norm's Avatar
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    Default Re: Java applet

    Please post the full text of the error message so we know what the full problem is.
    If you don't understand my answer, don't ignore it, ask a question.

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    ikocijan (July 3rd, 2012)

  6. #4
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    Default Re: Java applet

    Removing .class didn`t help.

    when I launch .html file chrome should display my calculator (eclipse displays it as an applet). I attached screen shoot. hope that helps.error.JPG

  7. #5
    Super Moderator Norm's Avatar
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    Default Re: Java applet

    If your class is in a package, you must include the package name with the class name.
    See the error message for the full classname that includes the packagename.
    I can't select and copy from an image so you will have to see the full name for yourself.
    If you don't understand my answer, don't ignore it, ask a question.

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    ikocijan (June 29th, 2012)

  9. #6
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    Default Re: Java applet

    do you mean something like this:
    HTML Code:
    <applet code = "com/PracticalJava/Lesson10/Calculator" width=300 height=250 />
    I tried that and I got error: ClassNotFoundException

    I made a simple program so that I am sure that everything works(used default package):

                 public class HelloWorld extends JApplet {
    		public void paint (Graphics g){
    			g.drawString ("Hello World", 50, 100);
    		}	
    }

    and then I made a html:

    HTML Code:
    <html>
             <body>
    
    <applet code = "HelloWorld" width=300 height=250/>
    
            </body>
           </html>
    Everthing works in Ecplise but Chrome shows ClassNotFoundException:


    error.JPG

    I tried with HelloWorld.class and only HelloWorld

  10. #7
    Super Moderator Norm's Avatar
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    Default Re: Java applet

    I got error: ClassNotFoundException
    Please copy the full text of the error message and paste it there.
    You can get the error message from the browser's java console.

    I can not copy text from an image to show what the problem is.
    If you don't understand my answer, don't ignore it, ask a question.

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    ikocijan (July 3rd, 2012)

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    Default Re: Java applet

    Quote Originally Posted by Norm View Post
    Please copy the full text of the error message and paste it there.
    You can get the error message from the browser's java console.

    I can not copy text from an image to show what the problem is.
    Well that is going to be a problem because I can not copy anything from that window. In chrome when I launch web page only that window pop- up and if I press Details it opens Java consoe. If I press Ignore program still won`t load and if I press Reload window pop- up again. I wish I could give you more but that is the only thing that happens.

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    Default Re: Java applet

    Please read the tutorial I posted, it addresses all of your issues. Hint: how do you separate packages?
    Useful links: How to Ask Questions the Smart Way | Use Code Tags | Java Tutorials
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    ikocijan (June 30th, 2012)

  15. #10
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    Default Re: Java applet

    if I press Details it opens Java console
    The Java console has a button for copying its contents.
    If you don't understand my answer, don't ignore it, ask a question.

  16. The Following User Says Thank You to Norm For This Useful Post:

    ikocijan (June 30th, 2012)

  17. #11
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    Default Re: Java applet

    Thank you for your replies. I will read the tutorial later today and try java console.

  18. #12
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    Default Re: Java applet

    I read all about creating and working with jar files and now everything works. Thank you guys for wasting your time on my problem

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