How to send Image over Socket in Java?

[Joncamp]

I am trying to transmit an Image object through a Socket connection in Java. The only thing I may be missing is how to get an image size in bytes so I know how many bytes are being transferred over the Socket.

I have the ServerSocket and Client working transferring data, and I have a cut-paste image working from a client Applet, and I have a Java program that saves Images to disk as JPEG/PNG.

How do you get the byte size of an Image object in Java?... or do you know of source code to a program that transferes images through Sockets?

Thanks,
Jon

 

[Diancecht]

Do you want to transfer the image or the object?

Cheers,
Dian

 

[Joncamp]

I'm trying to tranfer the Image it's self. I already have a routine to handle BufferedImage objects, writing them to a file. I was hoping I could use something similar with writing to a Socket InputStream and OutputStream to transfer the Image data.

Jon

 

[timw]

Well, if you can them to a file and read them back in again using the InputStream and OutputStream interfaces, using sockets should just be a matter of replacing your use of FileInputStream and FileOutputStream with the Sockets' InputStream and OutputStream at respective ends of the link.

Tim

 

[Diancecht]

Well, I don't know much about the Image object, but AFAIK, and object needs to be serializable to be sent through a socket.

I guess Image will have a reference to the file containing the image so that won't be send. I'd follow Tim's approach and send the image and not the object.

Cheers,
Dian

 

[timw]

Yeah, I looked at the Image class too when I read Jon's post and noticed it wasn't serializable. I don't know exactly which technique Jon is using to write his image to a file but if the image can be squirted into a file using a FileOutputStream, then it can be squirted down a socket via that socket's output stream as returned from the getOutputStream() method.

Tim

 

[Joncamp]

To save an Image to disk, it has to be transformed into a BufferedImage object, then you save the BufferedImage object to a file stream.

So using a BufferedImage one should be able to send the image through an IP Socket? I just don't know how?


Jon

 

[timw]

Assuming you're using ImageIO to save the BufferedImage, then something like this (I haven't compiled this or tested it, I just don't have the time, sorry).

//..BufferedImage in bImage;
//..Socket in sSocket;

  OutputStream os = null;
  try {
    os = sSocket.getOutputStream();
    ImageIO.write(bImage, "jpg", os);
  } catch (IOException ex){
    ex.printStackTrace();
  } finally {
    if ( os != null ){
      try { os.close(); } catch (IOException ex){}
    }
  }
  
//Housekeep your socket. If conversation done, close it.

This should give you a hint on how to handle the InputStream at the other end, too.

Tim

 

[Joncamp]

Looks interesting TimW, I have actually gotten a working app from another forum, but I'll try yours because yours allows one to send the image through the Socket stream in any format, if it works?

Thanks much,
Jon