From 96f699a0364fe86f309b72ece4ed1a91328cc258 Mon Sep 17 00:00:00 2001
From: Christopher Bohn <bohn@unl.edu>
Date: Tue, 5 Nov 2019 20:32:34 -0600
Subject: [PATCH] Gracefully handles case when port is already in use.
Closes #8
---
.../edu/unl/cse/csce361/socket_chat/Chat.java | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
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 5759bd0..aa0f804 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
@@ -48,9 +48,18 @@ public class Chat {
private Socket connectAsServer(Scanner userInput) throws IOException {
byte[] address = InetAddress.getLocalHost().getAddress();
System.out.println("Host address: " + address[0] + "." + address[1] + "." + address[2] + "." + address[3]);
- String prompt = "Select port number";
- int port = getPort(prompt, userInput);
- ServerSocket serverSocket = new ServerSocket(port);
+ int port;
+ ServerSocket serverSocket;
+ do {
+ String prompt = "Select port number";
+ port = getPort(prompt, userInput);
+ try {
+ serverSocket = new ServerSocket(port);
+ } catch (BindException ignored) {
+ System.out.println("Port " + port + " is already in use.");
+ serverSocket = null;
+ }
+ } while (serverSocket == null);
System.out.println("Waiting for client.");
return serverSocket.accept();
}
@@ -128,7 +137,7 @@ public class Chat {
haveGoodNumber = true;
try {
port = userInput.nextInt();
- if (port < 0) throw new InputMismatchException("Expected non-negative value, got " + port);
+ if (port <= 0) throw new InputMismatchException("Expected positive value, got " + port);
if (port >= 2 * (Short.MAX_VALUE + 1)) {
throw new InputMismatchException("Expected value less than 65536, got " + port);
}
--
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