public static void main(String[] args) throws Exception {
//////////////////// STAGE A//////////////////////////////////////////
int portNum = 12235;
// InetAddress ip=InetAddress.getLocalHost();
InetAddress ip = InetAddress.getByName("attu2.cs.washington.edu");
DatagramSocket sock = new DatagramSocket();
byte[] response = new byte[HEADER_SIZE + 16];
String partA = "hello world\0";
byte[] buf = createBuffer(partA.getBytes(), 0, STEP1);
DatagramPacket packet = new DatagramPacket(buf, buf.length, ip, portNum);
sock.send(packet);
packet = new DatagramPacket(response, response.length);
sock.receive(packet);
int[] a2 = partA(response); // putting the 4 ints from server into int[]
// for (int i = 0; i < a2.length; i++) {
// System.out.println(a2[i]);
// }
////////////////////// STAGE B////////////////////////////////////////
int numSent = 0;
int send = a2[0];
int len = a2[1];
portNum = a2[2];
int secretA = a2[3];
System.out.println("The secrets:\nA: " + secretA);
sock.setSoTimeout(500); // .5s
while (numSent < send) {
// create packet
buf = createBuffer(partB(numSent, len), secretA, STEP1);
packet = new DatagramPacket(buf, buf.length, ip, portNum);
sock.send(packet);
// send packet
try {
sock.receive(new DatagramPacket(response, response.length));
numSent++;
ByteBuffer temp = ByteBuffer.wrap(response);
checkHeader(temp, 4, secretA, STEP1);
// System.out.println(temp.getInt()); // For debug. See if counts up by 1
} catch (SocketTimeoutException e) {
// if there's a timeout, try again
continue;
}
}
response = new byte[HEADER_SIZE + 8]; // 8 bytes -- 2 integers
sock.receive(new DatagramPacket(response, response.length));
ByteBuffer bb = ByteBuffer.wrap(response);
// Header
checkHeader(bb, 8, secretA, STEP2);
// reset the port number to the one given
portNum = bb.getInt();
int secretB = bb.getInt();
System.out.println("B: " + secretB);
// close the UDP socket
sock.close();
/////////////////////////// STAGE C///////////////////////////////////
Socket socket = new Socket(ip, portNum);
InputStream in = socket.getInputStream();
OutputStream out = socket.getOutputStream();
response = new byte[HEADER_SIZE + 16]; // 4 ints given to us this time
in.read(response);
bb = ByteBuffer.wrap(response);
// Header
checkHeader(bb, 13, secretB, STEP2);
// num2 len2 secretC and char c
numSent = bb.getInt();
len = bb.getInt();
int secretC = bb.getInt();
System.out.println("C: " + secretC);
// stage d
byte c = (byte) bb.getChar();
buf = new byte[len];
Arrays.fill(buf, c);
for (int i = 0; i < numSent; i++) {
byte[] b = createBuffer(buf, secretC, STEP1);
out.write(b);
}
response = new byte[12 + 4]; // one integer. secretD plus header
in.read(response);
bb = ByteBuffer.wrap(response);
checkHeader(bb, 4, secretC, STEP2);
int secretD = bb.getInt();
socket.close();
in.close();
out.close();
System.out.println("D: " + secretD);
}
