Exception on sending big files through java sockets

Question

I'm creating a Chat in java for a university project, and one of the requirements is each user must have an image associate, this can be done through registration windows and data modification windows, in registration everything works great, but on the modification window, the program throws an exception when i try to send big files, both codes (registration and modification) are basiccally the same, changing only variables and path, but still gives my problem only in modification

Here is my code:

Client:

BufferedImage image = ImageIO.read(new    File(usuario.getImagen().getCanonicalPath()));
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
ImageIO.write(image, "jpg", byteArrayOutputStream);
byte[] size = ByteBuffer.allocate(4).putInt(byteArrayOutputStream.size()).array();
salida.write(size);
salida.write(byteArrayOutputStream.toByteArray());
salida.flush();

Server:

dir = new File ("." + "/Documentos/Imagenes de Verificacion/" +
                    usuarioRegistro.getNombreDeUsuario() + ".jpg");
sizeAr = new byte[4];
entrada.read(sizeAr);
size = ByteBuffer.wrap(sizeAr).asIntBuffer().get();
imageAr = new byte[size];
entrada.readFully(imageAr);
image = ImageIO.read(new ByteArrayInputStream(imageAr));
ImageIO.write(image, "jpg", new File(dir.getCanonicalPath()));
usuarioRegistro.setImagen(dir.getCanonicalFile());

And the exception is:

Exception in thread "Thread-0" java.lang.IllegalArgumentException: image == null!
at javax.imageio.ImageTypeSpecifier.createFromRenderedImage(ImageTypeSpecifier.java:925)
at javax.imageio.ImageIO.getWriter(ImageIO.java:1591)
at javax.imageio.ImageIO.write(ImageIO.java:1520)
at com.ucab.javachat.Servidor.model.ServidorModel.run(ServidorModel.java:198)

The line ServiorModel.java:198 is: ImageIO.write(image, "jpg", new File(dir.getCanonicalPath()));

In my tests i can send images of 20, 30, 80, 200 Kb, but when i try to send the 2.1mb file gives the error.

I think this i related with some data loose on the byteArray (maybe header data?) but what i dont know is how to fix it, my register window method uses the same sockets and OutputStream to send data and i succesfully send a 24mb image.

Answer 1

As per the documentation:

Returns a BufferedImage as the result of decoding a supplied File with an ImageReader chosen automatically from among those currently registered. The File is wrapped in an ImageInputStream. If no registered ImageReader claims to be able to read the resulting stream, null is returned . The current cache settings from getUseCacheand getCacheDirectory will be used to control caching in the ImageInputStream that is created.

Note that there is no read method that takes a filename as a String; use this method instead after creating a File from the filename.

This method does not attempt to locate ImageReaders that can read directly from a File; that may be accomplished using IIORegistry and ImageReaderSpi.

Make sure you register an ImageReader or wrap your file on a FileInputStream, but since your implementation works I bet it's the image causing issues therefore,

Make sure that your image is of type: GIF, PNG, JPEG, BMP, and WBMP for these are the types supported by the class.