Switch(int num) {
numNodes = num;
// Initialize listener server socket. REQUIRES PORT 65535 BE OPEN
while (true) {
try {
listener = new ServerSocket(65535);
break;
} catch (IOException e) {
System.err.println("Listener server socket failed to initialize");
continue;
}
}
receivePorts = new ArrayList<Integer>();
sendPorts = new ArrayList<Integer>();
usedPorts = new ArrayList<Integer>();
terminated = 0;
// Initialize termination flag
termflag = true;
// Initialize switching table
switchTable = new HashMap<Integer, Integer>();
// Initialize frame buffer
buffer = new ArrayDeque<Frame>();
/**
* Handles accepting connections, reassigning the connections, and closing connections on
* termination
*/
Thread a = new Thread() { // begin listener thread, reassigns nodes to open ports
public void run() {
int startingPort = 49153;
BufferedWriter writer = null;
Socket client;
System.out.println("Switch listener beginning loop");
while (termflag) {
client = null;
try {
listener.setSoTimeout(5000);
client = listener.accept(); // accept connection
System.out.println("Switch connected to client");
writer =
new BufferedWriter(
new OutputStreamWriter(
client.getOutputStream())); // get socket outputStream
for (; startingPort < 65534; startingPort++) // iterates until a free port is found
{
try {
ServerSocket tmp = new ServerSocket(startingPort);
tmp.close();
if (usedPorts.contains(startingPort)) {
throw new IOException();
}
System.out.println("Switch reassigning client to " + startingPort);
usedPorts.add(startingPort);
receivePorts.add(startingPort);
break;
} catch (IOException e) {
System.out.println("Port " + startingPort + " was taken");
continue;
}
}
receiveData(startingPort); // set up new receiver for reassigned connection
writer.write(Integer.toString(startingPort) + "\n"); // reassign the client
startingPort++;
for (;
startingPort < 65536;
startingPort++) // iterates until a second free port is found
{
try {
ServerSocket tmp = new ServerSocket(startingPort);
tmp.close();
if (usedPorts.contains(startingPort)) {
throw new IOException();
}
usedPorts.add(startingPort);
sendPorts.add(startingPort);
break;
} catch (IOException e) {
continue;
}
}
writer.write(Integer.toString(startingPort) + "\n");
startingPort++;
writer.close();
client.close();
} catch (SocketTimeoutException e) {
System.out.println("Switch timed out in listener");
continue;
} catch (IOException e) {
System.err.println("Failed to establish reassigned connection to client");
e.printStackTrace();
}
}
System.out.println("Switch listener is returning");
return;
}
};
a.start();
sendData();
}
