diff --git a/src/main/java/edu/unl/cse/csce361/socket_chat/Chat.java b/src/main/java/edu/unl/cse/csce361/socket_chat/Chat.java
index b99ffa43ec69f9be2cae5606f8addc13f46d3294..8d866d83e8540950e730ce3f6caf505385155cc1 100644
--- a/src/main/java/edu/unl/cse/csce361/socket_chat/Chat.java
+++ b/src/main/java/edu/unl/cse/csce361/socket_chat/Chat.java
@@ -1,86 +1,39 @@
package edu.unl.cse.csce361.socket_chat;
import java.io.*;
-import java.net.InetAddress;
-import java.net.ServerSocket;
-import java.net.Socket;
+import java.net.*;
import java.util.InputMismatchException;
import java.util.Scanner;
+import static java.lang.Thread.sleep;
+
public class Chat {
+ private static final int MAXIMUM_CONNECTION_ATTEMPTS = 10;
private Socket socket;
private Scanner scanner;
private boolean isHost;
public Chat() {
scanner = new Scanner(System.in);
- try {
- socket = connect();
- } catch (IOException ioException) {
- System.err.println("Connection failed: " + ioException);
- System.exit(1);
- }
- }
-
- @SuppressWarnings("WeakerAccess")
- public void communicate() {
- try {
- communicate(
- new BufferedReader(new InputStreamReader(System.in)),
- new BufferedReader(new InputStreamReader(socket.getInputStream())),
- System.out,
- new PrintStream(socket.getOutputStream()));
- socket.close();
- } catch (IOException ioException) {
- System.err.println("Connection dropped: " + ioException);
- System.exit(1);
- }
- }
-
- @SuppressWarnings("SameParameterValue")
- private void communicate(BufferedReader localInput,
- BufferedReader remoteInput,
- PrintStream localOutput,
- PrintStream remoteOutput) {
- System.out.println("Connection established. Host goes first.");
- String message = "";
- boolean myTurnToTalk = isHost;
- try {
- while (!message.equals("EXIT")) {
- if (myTurnToTalk) {
- message = localInput.readLine();
- remoteOutput.println(encipher(message));
- } else {
- message = decipher(remoteInput.readLine());
- localOutput.println(message);
- }
- myTurnToTalk = !myTurnToTalk;
- }
- } catch (IOException ioException) {
- System.err.println("Connection dropped: " + ioException);
- System.exit(1);
- }
+ socket = connect();
}
- private String encipher(String plaintext) {
-// String ciphertext = ...;
-// return ciphertext;
- return plaintext;
- }
+ // THESE METHODS SET UP CONNECTION
- private String decipher(String ciphertext) {
-// String plaintext = ...;
-// return plaintext;
- return ciphertext;
- }
-
- private Socket connect() throws IOException {
+ private Socket connect() {
System.out.print("Are you the chat host? [Y] ");
String answerString = scanner.nextLine().toUpperCase();
char answer = answerString.length() > 0 ? answerString.charAt(0) : 'Y';
isHost = (answer != 'N');
- return isHost ? connectAsServer() : connectAsClient();
+ Socket socket = null;
+ try {
+ socket = isHost ? connectAsServer() : connectAsClient();
+ } catch (IOException ioException) {
+ System.err.println("Connection failed: " + ioException);
+ System.exit(1);
+ }
+ return socket;
}
private Socket connectAsServer() throws IOException {
@@ -98,7 +51,28 @@ public class Chat {
String prompt = "Enter port host is opening at " +
address[0] + "." + address[1] + "." + address[2] + "." + address[3];
int port = getPort(prompt);
- return new Socket(InetAddress.getByAddress(address), port);
+ Socket socket = null;
+ int attemptCount = 0;
+ do {
+ try {
+ sleep(1000*attemptCount++);
+ } catch (InterruptedException ignored) {
+ }
+ try {
+ socket = new Socket(InetAddress.getByAddress(address), port);
+ } catch (ConnectException ignored) {
+ System.out.println("Attempt " + attemptCount + ": Chat server is not yet ready at " +
+ address[0] + "." + address[1] + "." + address[2] + "." + address[3] + ":" + port);
+ if (attemptCount < MAXIMUM_CONNECTION_ATTEMPTS) {
+ System.out.println("Will attempt to connect again in " + attemptCount + " seconds");
+ socket = null;
+ } else {
+ System.err.println("Exceeded maximum number of connection attempts. Terminating.");
+ System.exit(1);
+ }
+ }
+ } while (socket == null);
+ return socket;
}
private byte[] getRemoteHostAddress() {
@@ -159,6 +133,66 @@ public class Chat {
return port;
}
+ // THESE METHODS PERFORM CHAT AFTER CONNECTION IS SET UP
+
+ @SuppressWarnings("WeakerAccess")
+ public void communicate() {
+ try {
+ communicate(
+ new BufferedReader(new InputStreamReader(System.in)),
+ new BufferedReader(new InputStreamReader(socket.getInputStream())),
+ System.out,
+ new PrintStream(socket.getOutputStream()));
+ } catch (IOException ioException) {
+ System.err.println("Failed to set up input/output streams: " + ioException);
+ System.err.println("Terminating."); // I'm pretty sure this is recoverable if the client is waiting on the server
+ System.exit(1);
+ }
+ try {
+ socket.close();
+ } catch (IOException ioException) {
+ System.err.println("Error while closing socket: " + ioException);
+ // We're terminating anyway, note the error and continue normal termination
+ }
+ }
+
+ @SuppressWarnings("SameParameterValue")
+ private void communicate(BufferedReader localInput,
+ BufferedReader remoteInput,
+ PrintStream localOutput,
+ PrintStream remoteOutput) {
+ System.out.println("Connection established. Host goes first.");
+ String message = "";
+ boolean myTurnToTalk = isHost;
+ try {
+ while (!message.equals("EXIT")) {
+ if (myTurnToTalk) {
+ message = localInput.readLine();
+ remoteOutput.println(encipher(message));
+ } else {
+ message = decipher(remoteInput.readLine());
+ localOutput.println(message);
+ }
+ myTurnToTalk = !myTurnToTalk;
+ }
+ } catch (IOException ioException) {
+ System.err.println("Connection dropped: " + ioException);
+ System.exit(1);
+ }
+ }
+
+ private String encipher(String plaintext) {
+// String ciphertext = ...;
+// return ciphertext;
+ return plaintext;
+ }
+
+ private String decipher(String ciphertext) {
+// String plaintext = ...;
+// return plaintext;
+ return ciphertext;
+ }
+
public static void main(String[] args) {
Chat chat = new Chat();
chat.communicate();