Writing Image from Applet

[Meet Gaurav]

Hi,

I have a small applet in that am viewing a image using

URL url = new URL(getCodeBase(), "sample.jpg");
BufferedImage image = ImageIO.read(url);

After that am writing a new image using

URL url1 = new URL(getCodeBase(), "new.jpg");
ImageOutputStream ios = ImageIO.createImageOutputStream(url1);
ImageIO.write(image, type, ios);

But it's not working. Please assist me how to write image from Applet

[Ulf Dittmer]

A static image served by a web server is a read-only URL. If you want to save images, then you need to send the image data to an active server-side component (like a servlet) over HTTP. That component can then save the image data on the server.

[Meet Gaurav]

Thanks a lot..I will try that.. But in case if it a stanalone Applet.. Then how to save an image to the server machine..

[Meet Gaurav]

Ulf,

Now it's working fine. But please assit me how to save an image now. My Application is struts and the applet class is out of WEB-INF directory, Then how can I pass the image from applet to jsp or servlet.

Please assit me

[Ulf Dittmer]

Do you mean a stand alone application? (Applets are running inside of web browsers.) They can use any means supported by the server - HTTP upload, WebDAV, FTP, shared directory, etc. - depends on what's available.

[Ulf Dittmer]

Then how can I pass the image from applet to jsp or servlet.

The applet can make an HTTP POST to a servlet, and in that call send all data needed to reconstitute the image file.

[Meet Gaurav]

But in my it's a struts application. Also my applet class are out of WEB-INF Folder.. So Don't know how to call the struts handler.. Please help

[Ulf Dittmer]

Yes, there are two parts to it - the applet would contain code that makes the HTTP call, and the web app would contain code (a servlet or a Struts action) that receives the binary data sent by the image.

I suggest to start by writing an applet that makes a successful HTTP call to a servlet (or Struts action); you can worry about sending the actual image data once you have that.

[Meet Gaurav]

Am trying to access a action from the applet using

URL urlServlet = new URL(getCodeBase(), "Dummy.do");

getCodeBase() - Is returning Nullponiterexception.


Any suggestion please.

[Ulf Dittmer]

Are you running the applet off a server? Meaning, does the URL in the browser start with "http"? Otherwise there's no code base that could meaningfully be returned.

[Meet Gaurav]

After placing URL urlServlet = new URL(getCodeBase(), "Dummy.do"); in the init() it's working..

Anyway to change the getcodebase() value ? Because am placing my applets in a different folder am getting that folder name too appended in the url

Thanks..

[Ulf Dittmer]

If the servlet has a different URL (which is quite likely), you can pass that URL to the applet through an applet parameter. That's a good idea anyway instead of putting any part of the servlet URL in the applet code.

[Meet Gaurav]

Thats Great !!... I am doing that now

But am getting java.io.NotSerializableException: java.awt.image.BufferedImage while writing from applet

  
OutputStream outstream = urlConn.getOutputStream();
			ObjectOutputStream oos = new ObjectOutputStream(outstream);
			oos.writeObject(image);
			oos.flush();
			oos.close();

Can I try this or any other good solution ?

[Ulf Dittmer]

RMI wouldn't work, but you could use the getRGB method mentioned there.

[Meet Gaurav]

My Applet is not hitting my action. What goes wrong please help ?

 	private void onSendData(BufferedImage image) {

		try {
		
			String toservlet = "http://localhost:8080/AAM/VProfile.do";
            
            URL servleturl = new URL(toservlet);
            URLConnection servletconnection = servleturl.openConnection();
            servletconnection.setDoInput(true);
            servletconnection.setDoOutput(true);
            servletconnection.setUseCaches(false);
            servletconnection.setDefaultUseCaches(false);
           
            DataOutputStream out = new DataOutputStream(servletconnection.getOutputStream());
            out.writeChars("TESTINGWQWQWQWQW~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~");
           
            out.flush();
            out.close();


		} catch (Exception ex) {
			ex.printStackTrace();
		}
	}   

[Ulf Dittmer]

You need to handle the response from the servlet, otherwise the request won't even get sent.

[Meet Gaurav]

Great Ulf.... After adding below code.. Hit goes to ApplicationController(Struts Controller) but not going to my Struts Action Handler... Any guess

Please share your thoughts

   inFromServlet = new BufferedReader(new InputStreamReader(servletConnection.getInputStream()));
	        
            String str;
            while (null != ((str = inFromServlet.readLine())))
            {
            	System.out.println("Reading servlet response: " + str);
            }
            
            inFromServlet.close(); 

[Meet Gaurav]

After removing the waitpage from struts-config it works..!!.. why it's not working if the please wait page is enabled..