通过循环从套接字读取数据时获取“ java.io.EOFException”

Question

I am making a chess game application for a practice and finished up all the functionalities.

Now I am trying to implement the networking part so to enable 2 players mode...

In my server code I am using a loop to continuously get the data from both player turn by turn.

At the first turn of each player, the server works just fine and I confirmed the data is transferred correctly to the other player. But when it goes back to int[] data1 = (int[]) in1.readUnshared(); this very first line of the loop,

java.io.EOFException
    at java.io.ObjectInputStream$BlockDataInputStream.peekByte(Unknown Source)
    at java.io.ObjectInputStream.readObject0(Unknown Source)
    at java.io.ObjectInputStream.readObject(Unknown Source)

the error occurs...

while(true){

    int[] data1 = (int[]) in1.readUnshared(); // THIS PART!!

    if(data1.length != 96)
        break;

    out2.writeUnshared(data1);
    out2.flush();

    int[] data2 = (int[]) in2.readUnshared();
    if(data1.length != 96)
        break;

    out1.writeUnshared(data2);
    out1.flush();
}

Here, "in" and "out" variables are class variables I declared

static ObjectInputStream in1;
static ObjectInputStream in2;
static ObjectOutputStream out1;
static ObjectOutputStream out2;

and I initilized them on the main function like this :

in1 = new ObjectInputStream(player1.getInputStream());

Is there any problem with the way I initialized streams...? been stuck for this problem for quite long... and desperate to see my application working.

Answer 1

I think this is an off by one error, it might have to do with you flushing the buffer but then not writing or checking if it is empty before calling readUnshared().

EOFException just said you reached the end of the stream or file (End Of File).

I can't really debug it just with the code you posted. But make sure you are writing moves into wherever the "unshared" moves are being kept, or check, before calling the Stream.

Answer 2

EOFException is thrown when you call readObject() , readInt() , etc., on a socket that has no more buffered data to read and has been closed by the other end, just like readLine() returning null or read() returning -`. It is a 'normal exception'. Just close the socket and forget about the connection.