令人头疼的Connection Reset

 int read(byte b[], int off, int length, int timeout) throws IOException {
        int n;

        // EOF already encountered
        if (eof) {
            return -1;
        }

        // connection reset
        if (impl.isConnectionReset()) {
            throw new SocketException("Connection reset");
        }

        // bounds check
        if (length <= 0 || off < 0 || length > b.length - off) {
            if (length == 0) {
                return 0;
            }
            throw new ArrayIndexOutOfBoundsException("length == " + length
                    + " off == " + off + " buffer length == " + b.length);
        }

        boolean gotReset = false;

        // acquire file descriptor and do the read
        FileDescriptor fd = impl.acquireFD();
        try {
            n = socketRead(fd, b, off, length, timeout);
            if (n > 0) {
                return n;
            }
        } catch (ConnectionResetException rstExc) {
            gotReset = true;
        } finally {
            impl.releaseFD();
        }

        /*
         * We receive a "connection reset" but there may be bytes still
         * buffered on the socket
         */
        if (gotReset) {
            impl.setConnectionResetPending();
            impl.acquireFD();
            try {
                n = socketRead(fd, b, off, length, timeout);
                if (n > 0) {
                    return n;
                }
            } catch (ConnectionResetException rstExc) {
            } finally {
                impl.releaseFD();
            }
        }

        /*
         * If we get here we are at EOF, the socket has been closed,
         * or the connection has been reset.
         */
        if (impl.isClosedOrPending()) {
            throw new SocketException("Socket closed");
        }
        if (impl.isConnectionResetPending()) {
            impl.setConnectionReset();
        }
        if (impl.isConnectionReset()) {
            throw new SocketException("Connection reset");
        }
        eof = true;
        return -1;