Applet中的图像未显示在网页中

Question

I am trying to display a JPEG image and a moving dot on a Java applet which I am using on a web based application. However, when I run the applet it works fine, but when I display the applet from the JSP page, I get the moving dot but not the JPEG image.

Is there a specific folder where the JPEG needs to be?

These are the 2 methods i use for drawing the picture and the moving dot on the screen.

public class mapplet extends Applet implements Runnable {

int x_pos = 10;
int y_pos = 100;
int radius = 20;
Image img, img2;
Graphics gr;
URL base;
MediaTracker m;

@Override
public void init() {

        mt = new MediaTracker(this);

        try {
            //getDocumentbase gets the applet path.
           base = getCodeBase();
          img = getImage(base, "picture.jpg");
            m.addImage(img, 1);
            m.waitForAll();
        } catch (InterruptedException ex) {
            Logger.getLogger(movement.class.getName()).log(Level.SEVERE, null, ex);
       }

public void paint (Graphics g) {

 g.drawImage(img, 0, 0, this);
// set color
 g.setColor (Color.red);

// paint a filled colored circle
g.fillOval (x_pos - radius, y_pos - radius, 2 * radius, 2 * radius);

}

The code one below is the call from the jsp page

<applet archive="mapplet.jar" code="myapplets/mapplet.class" width=350 height=200>
</applet>

The jar file and the picture are in the same folder as the jsp page, and there is also a folder containing the contents of the class and image of the applet in the web section of the application. The applet loads fine however the picture doesn't display. I think it's not the code but the location of the picture that is causing a problem.

Thanks

Answer 1

please check your path ..or to resolve it please put your files inside a folder and pack it with JAR file.and provide the relative path of image files inside your jar. Like: let your applet name is myapp.class in package demoapp then put your files in dir "images" inside demoapp and provide path relative to this path in all your java code. dont forget to include image files in jar build.

Answer 2

Yes, the image should be in the same folder as the source code. I would recommend to do a folder called images and inside it put all your images and just change "picture.jpg" to "\\images\\picture.jpg". Check your website directory to see if the image is in the same folder as the source code.

Answer 3

Some comments that might make it more clear for you.

//getDocumentbase gets the applet path.

No. getDocumentBase() provides the path to the web page. But that is neither here, nor there, since this applet actually calls..

base = getCodeBase();

..which provides the codebase. The codebase defaults to the directory of the web page, unless a codebase parameter is specified in the applet element. Since the applet element declares no codebase , the base will be the same URL as the document base.

---

BTW: In the applet element

code="myapplets/mapplet.class"

..should be..

code="myapplets.mapplet"

And since common nomenclature for Java class names is EachWordUpperCase , the class name should be changed.

Doe the applet declare?

package myapplets;

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BTW (2):

there is also a folder containing the contents of the class and image of the applet in the web section of the application.

What does that mean? Please provide complete paths from the root of the server to all resources (eg the HTML/JSP, Jar file & image) used.