Shifted From Command Prompt to Net Beans

Question

I have just installed Netbeans IDE 7.0 and tried to run my project (which executes fine when I run with traditional method using command prompt) based on image processing but applet viewer says start: applet not initialized whereas compiling (build task in Netbeans) is successful.

Here I am attaching 2 relevant Java files while whole project has 3-4 more java files for image rendering.

/* 
* <applet code=ImageFilterDemo width=350 height=450> 
* <param name=img value=strawberry.jpeg> 
* <param name=filters value="Grayscale+Invert+Contrast+Blur+Sharpen"> 
* </applet> 
*/  
import java.applet.*;  
import java.awt.*;  
import java.awt.event.*;  
import java.util.*;  
import java.awt.image.* ;  
public class ImageFilterDemo extends Applet implements ActionListener {  

Image img;  
PlugInFilter pif;  
Image fimg;  
Image curImg;  
LoadedImage lim;  
Label lab;  
Button reset;  
Button histograph;  

Dimension d;  
static int iw, ih;  
int pixels[];  
static int w, h,just;  
static int hist[] = new int[256];  
static int max_hist = 0;  

public void init() {  
setLayout(new BorderLayout());  
Panel p = new Panel();  
add(p, BorderLayout.SOUTH);  
reset = new Button("Reset");  
histograph = new Button("Histograph");  
reset.addActionListener(this);  
histograph.addActionListener(this);  
p.add(reset);  
p.add(histograph);  
StringTokenizer st = new StringTokenizer(getParameter("filters"), "+");  
while(st.hasMoreTokens()) {  
Button b = new Button(st.nextToken());  
b.addActionListener(this);  
p.add(b);  
}  
lab = new Label("");  
add(lab, BorderLayout.NORTH);  
img = getImage(getDocumentBase(),"strawberry.jpeg");  
lim = new LoadedImage(img);  
add(lim, BorderLayout.CENTER);  

d = getSize();  
w = d.width;  
h = d.height;  
try {  
//img = getImage(getDocumentBase(), getParameter("img"));  
MediaTracker t = new MediaTracker(this);  
t.addImage(img, 0);  
t.waitForID(0);  
iw = img.getWidth(null);  
ih = img.getHeight(null);  
pixels = new int[iw * ih];  
PixelGrabber pg = new PixelGrabber(img, 0, 0, iw, ih,  
pixels, 0, iw);  
pg.grabPixels();  
} catch (InterruptedException e) { };  
for (int i=0; i<iw*ih; i++) {  
int pii = pixels[i];  
int r = 0xff & (pii >> 16);  
int g = 0xff & (pii >> 8);  
int b = 0xff & (pii);  
int y = (int) (.33 * r + .56 * g + .11 * b);  
hist[y]++;  
}  
for (int i=0; i<256; i++) {  
if (hist[i] > max_hist)  
max_hist = hist[i];  
}  
}  

public void actionPerformed(ActionEvent ae) {  
String a = "";  
try {  
a = (String)ae.getActionCommand();  
if (a.equals("Reset")) {  
lim.set(img);  
lab.setText("Normal");  
}  
else if(a.equals("Histograph")){  
lab.setText("Histo_graph");  
just=1;  
lim.repaint();  
}   
else {  
pif = (PlugInFilter) Class.forName(a).newInstance();  
fimg = pif.filter(this, img);  
lim.set(fimg);  
lab.setText("Filtered: " + a);  
}  
repaint();  
} catch (ClassNotFoundException e) {  
lab.setText(a + " not found");  
lim.set(img);  
repaint();  
} catch (InstantiationException e) {  
lab.setText("could't new " + a);  
} catch (IllegalAccessException e) {  
lab.setText("no access: " + a);  
}  
}  
}  


// 2nd file
import java.awt.*;  

public class LoadedImage extends Canvas {  
Image img;  

public LoadedImage(Image i) {  
set(i);  
}  

void set(Image i) {  
MediaTracker mt = new MediaTracker(this);  
mt.addImage(i, 0);  
try {  
mt.waitForAll();  
} catch (InterruptedException e) { };  
img = i;  
repaint();  
}  


public void paint(Graphics g) {  
if (img == null) {  
g.drawString("no image", 10, 30);  
}  

else if(ImageFilterDemo.just==1){  
int x = (ImageFilterDemo.w - 256) / 2;  
int lasty = ImageFilterDemo.h - ImageFilterDemo.h * ImageFilterDemo.hist[0] / ImageFilterDemo.max_hist;  
for (int i=0; i<256; i++, x++) {  
int y = ImageFilterDemo.h - ImageFilterDemo.h * ImageFilterDemo.hist[i] / ImageFilterDemo.max_hist;  
g.setColor(new Color(i, i, i));  
g.fillRect(x, y, 1, ImageFilterDemo.h);  
g.setColor(Color.red);  
g.drawLine(x-1,lasty,x,y);  
lasty = y;  
}  
ImageFilterDemo.just=0;  
}   
else {  
g.drawImage(img, 0, 0, this);  
}  
}  

public Dimension getPreferredSize() {  
return new Dimension(img.getWidth(this), img.getHeight(this));  
}  
public Dimension getMinimumSize() {  
return getPreferredSize();  
}  
}  

Is there any changes we have to make in settings or coding when we change from running from traditional command prompt, to Netbeans?

Answer 1

Hope this little tutorial helps, http://netbeans.org/kb/docs/web/applets.html

Answer 2

I would create a new project in NetBeans and have a look at how it works with Applets by default.

If you add an Applet to your project (new File -> Swing GUI forms -> JApplet Form)

have a look at the init code that is generated for you

@Override
    public void init() {
        /* Create and display the applet */
        try {
            java.awt.EventQueue.invokeAndWait(new Runnable() {

                public void run() {
                    initComponents();
                }
            });
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

I would think that your code would need a block like this to able to do a 'File Run' or 'Project Run' in NetBeans

Answer 3

You have to run your applet in javaWeb if i remember correctly.

Properties -> Run -> Run with Java Web Start.