I am attempting to send an image from my android device to my computer via a socket. The problem is the input stream on my computer reads in every single byte but the last set of them. I have tried trimming the byte array down and sending it, I've 开发者_StackOverflowmanually written out -1 to the outputstream multiple times but the inputstream never reads -1. It just hangs waiting for data. I've also tried not closing the stream or sockets to see if it was some sort of timing issue, but that didn't work as well.

Client side (Android Phone)

//This has to be an objectoutput stream because I write objects to it first
InputStream is = An image's input stream android
ObjectOutputStream objectOutputStream = new ObjectOutputStream(socket.getOutputStream());
objectOutputStream.writeObject(object);
objectOutputStream.flush();

byte[] b = new byte[socket.getSendBufferSize()];
int read = 0;
while ((read = is.read(b)) != -1) {
   objectOutputStream.write(b, 0, read);
   objectOutputStream.flush();
   b = new byte[socket.getSendBufferSize()];
}
//Tried manually writing -1 and flushing here
objectOutputStream.close();
is.close();
socket.close();

Server Side (Computer) This bit of code takes place after the object input stream reads in the objects sent. It only starts to read when the file starts to send

File loc = Location of where the file is stored on the computer
loc.createNewFile();
FileOutputStream os = new FileOutputStream(loc);
Socket gSocket = The socket
ObjectInputStream gInputStream = Object Input stream created from the sockets input stream already used to read in the previous objects

byte[] b = new byte[gSocket.getReceiveBufferSize()];
int read = 0;
while ((read = gInputStream.read(b)) != -1) {
   os.write(b, 0, read);
   os.flush();
   b = new byte[gSocket.getReceiveBufferSize()];
}

os.close();

This code never reads in -1 even if I write -1 directly and flush the stream. The outcome is java.net.SocketException: Connection reset when the stream or socket from the android device is closed. The picture is almost completely sent but the very last pixels of the picture are gray. I also even tried using the out/input stream directly from the socket instead of using the already created objectinputstream/objectoutputstream and it still doesn't work.

---

Firstly, I think you misunderstood the meaning of EOF (-1). It doesn't mean the server wrote a -1, it means the server closed the stream.

I think your main problem though is that both the server and the client are reading in a loop, and neither get to the point where they close the stream. They are deadlocked - both are waiting for the other one to close first.

Your client:

Your server:

If you know that you have no more data to write then just close the stream.

---

Since you're already using ObjectInputStream and ObjectOutputStream, you can use their respective readObject and writeObject methods to read/write entire objects at a time. Maybe you could send/receive the entire byte array as an object?

On your android:

1) byte[] imageBytes = ...; // contains the Image

2) objectOutputStream.writeObject(imageBytes);

On your computer:

1) byte[] imageBytes = (byte[])readObject();

2) get image from imageBytes

Of course, you'll have to use readObject from within a thread since it'll block.

---

You are writing byte[] arrays as objects, bur reading bytes. You should be reading Objects and casting them to byte[]. EOS will cause an EOFException to be thrown.