Java 聊天应用程序的代码指南65

在 Java 中开发聊天应用程序涉及创建一个多线程服务器应用程序和多个客户端应用程序。服务器监听传入的连接，并为连接的客户端维护一个列表。客户端向服务器发送消息，服务器将消息转发给其他所有连接的客户端。本指南将介绍在 Java 中创建聊天应用程序所需的基本代码。

服务器代码

服务器代码使用 ServerSocket 类来监听传入的连接。一旦客户端连接，它创建一个新的线程来处理该连接。处理线程不断从客户端读取传入消息，并将消息转发给其他所有连接的客户端。服务器代码可能如下所示：```java
import .*;
import .*;
public class ChatServer {
private ServerSocket serverSocket;
private List clients;
public ChatServer(int port) throws IOException {
serverSocket = new ServerSocket(port);
clients = new ArrayList();
}
public void start() throws IOException {
while (true) {
Socket clientSocket = ();
ClientHandler clientHandler = new ClientHandler(clientSocket);
(clientHandler);
();
}
}
private class ClientHandler extends Thread {
private Socket clientSocket;
private BufferedReader in;
private PrintWriter out;
public ClientHandler(Socket clientSocket) throws IOException {
= clientSocket;
in = new BufferedReader(new InputStreamReader(()));
out = new PrintWriter((), true);
}
@Override
public void run() {
try {
while (true) {
String message = ();
if (message == null) {
break;
}
for (ClientHandler client : clients) {
if (client != this) {
(message);
}
}
}
} catch (IOException e) {
();
} finally {
try {
();
} catch (IOException e) {
();
}
}
}
}
public static void main(String[] args) throws IOException {
int port = 8080;
if ( > 0) {
port = (args[0]);
}
ChatServer server = new ChatServer(port);
();
}
}
```

客户端代码

客户端代码使用 Socket 类连接到服务器。一旦连接，它创建一个输出流来向服务器发送消息。客户端代码可能如下所示：```java
import .*;
import .*;
public class ChatClient {
private Socket clientSocket;
private PrintWriter out;
public ChatClient(String host, int port) throws IOException {
clientSocket = new Socket(host, port);
out = new PrintWriter((), true);
}
public void start() {
BufferedReader in = new BufferedReader(new InputStreamReader());
try {
while (true) {
String message = ();
if (message == null) {
break;
}
(message);
}
} catch (IOException e) {
();
} finally {
try {
();
} catch (IOException e) {
();
}
}
}
public static void main(String[] args) throws IOException {
String host = "localhost";
int port = 8080;
if ( > 0) {
host = args[0];
}
if ( > 1) {
port = (args[1]);
}
ChatClient client = new ChatClient(host, port);
();
}
}
```