解释public void start() { try { while (true) { String input = in.readLine(); if (input == null) { break; } System.out.println(input); if (input.equals("Login successful")) { handleLogin(); } else if (input.equals("Goodbye")) { break; } } } catch (IOException e) { System.out.println("Failed to read from server socket: " + e.getMessage()); } finally { try { socket.close(); } catch (IOException e) { System.out.println("Failed to close server socket: " + e.getMessage()); } } }
时间: 2024-02-14 22:23:42 浏览: 32
这段代码是一个方法,名为 start()。该方法是用于从服务器端读取数据并进行处理的。在方法中,通过一个 while 循环持续地读取从服务器端传来的数据,如果读取到的数据为 null 或者为 "Goodbye",则会退出循环并关闭 socket 连接。如果读取到的数据为 "Login successful",则会调用 handleLogin() 方法进行处理。在 try-catch-finally 结构中,使用了异常处理机制来保证程序的正常运行。如果出现了读取或关闭 socket 的异常,会在控制台输出错误信息。
相关问题
import java.io.BufferedReader; import java.io.InputStreamReader; import java.io.PrintWriter; import java.net.Socket; import java.util.Scanner; public class Client { public static void main(String[] args) { new Client().go();// 创建一个新的 client 对象,并调用 go() 方法 } public void go() { try { Socket sock = new Socket("127.0.0.1", 5000); InputStreamReader streamReader = new InputStreamReader(sock.getInputStream()); BufferedReader reader = new BufferedReader(streamReader); PrintWriter writer = new PrintWriter(sock.getOutputStream()); System.out.println("Connected to server."); System.out.println("请输入你想对服务端说的话:"); Thread readerThread = new Thread(new IncomingReader(reader)); readerThread.start(); Scanner userInput = new Scanner(System.in); while (true) { String message = userInput.nextLine(); writer.println(message); writer.flush(); } } catch (Exception ex) { ex.printStackTrace(); } } public class IncomingReader implements Runnable { BufferedReader reader; public IncomingReader(BufferedReader reader) { this.reader = reader; } public void run() { String message; try { while ((message = reader.readLine()) != null) { System.out.println(message); } } catch (Exception ex) { ex.printStackTrace(); } } } }请在原有代码的基础上添加对应的注释
下面是针对给出代码的注释说明:
```java
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.Scanner;
public class Client {
public static void main(String[] args) {
new Client().go(); // 创建一个新的 client 对象,并调用 go() 方法
}
public void go() {
try {
Socket sock = new Socket("127.0.0.1", 5000); // 创建 Socket 连接到指定 IP 地址和端口号
InputStreamReader streamReader = new InputStreamReader(sock.getInputStream()); // 创建输入流读取服务器发送的消息
BufferedReader reader = new BufferedReader(streamReader);
PrintWriter writer = new PrintWriter(sock.getOutputStream()); // 创建输出流向服务器发送消息
System.out.println("Connected to server."); // 连接成功,输出提示信息
System.out.println("请输入你想对服务端说的话:");
Thread readerThread = new Thread(new IncomingReader(reader)); // 创建一个线程用于读取服务器发送的消息
readerThread.start(); // 启动线程
Scanner userInput = new Scanner(System.in); // 创建 Scanner 对象,用于读取用户输入的消息
while (true) {
String message = userInput.nextLine(); // 读取用户输入的消息
writer.println(message); // 向服务器发送消息
writer.flush(); // 立即刷新输出流
}
} catch (Exception ex) {
ex.printStackTrace(); // 捕获并打印异常
}
}
public class IncomingReader implements Runnable { // 该类实现 Runnable 接口,用于在新线程中读取服务器发送的消息
BufferedReader reader;
public IncomingReader(BufferedReader reader) {
this.reader = reader;
}
public void run() {
String message;
try {
while ((message = reader.readLine()) != null) { // 循环读取服务器发送的消息
System.out.println(message); // 输出服务器发送的消息
}
} catch (Exception ex) {
ex.printStackTrace(); // 捕获并打印异常
}
}
}
}
```
使用Java生成2.编写一对多的聊天程序,程序由服务器和客户端两部分构成,两部分的交互方式如下: a.客户端发送命令:”xu”/> 给服务器端注册用户,服务器端如果允许注册,则返回消息:”register” state=”ok” />,否则返回消息:”register” state=”error” message=”” />
好的,这是一个具体的问题,我可以为您提供相关的Java代码示例。以下是一个简单的服务器端和客户端程序,实现了注册用户和聊天功能。
服务器端代码:
```java
import java.io.*;
import java.net.*;
import java.util.*;
public class Server {
private static final int PORT = 12345;
private static Map<String, Socket> clients = new HashMap<>();
public static void main(String[] args) {
try (ServerSocket server = new ServerSocket(PORT)) {
System.out.println("Server started");
while (true) {
Socket client = server.accept();
handleClient(client);
}
} catch (IOException e) {
System.err.println("Server error: " + e.getMessage());
}
}
private static void handleClient(Socket client) {
new Thread(() -> {
try (BufferedReader in = new BufferedReader(new InputStreamReader(client.getInputStream()));
PrintWriter out = new PrintWriter(client.getOutputStream(), true)) {
String username = registerUser(client, in, out);
if (username == null) {
return;
}
broadcastMessage(username + " joined the chat");
String input;
while ((input = in.readLine()) != null) {
if (input.equalsIgnoreCase("quit")) {
out.println("Goodbye!");
break;
}
broadcastMessage(username + ": " + input);
}
clients.remove(username);
broadcastMessage(username + " left the chat");
} catch (IOException e) {
System.err.println("Client error: " + e.getMessage());
}
}).start();
}
private static String registerUser(Socket client, BufferedReader in, PrintWriter out) throws IOException {
out.println("Enter username:");
String username = in.readLine();
if (clients.containsKey(username)) {
out.println("Username already taken");
return null;
} else {
clients.put(username, client);
out.println("register state=\"ok\"");
return username;
}
}
private static void broadcastMessage(String message) {
for (Socket client : clients.values()) {
try (PrintWriter out = new PrintWriter(client.getOutputStream(), true)) {
out.println(message);
} catch (IOException e) {
System.err.println("Error broadcasting message: " + e.getMessage());
}
}
}
}
```
客户端代码:
```java
import java.io.*;
import java.net.*;
public class Client {
private static final String SERVER_ADDRESS = "localhost";
private static final int SERVER_PORT = 12345;
public static void main(String[] args) {
try (Socket socket = new Socket(SERVER_ADDRESS, SERVER_PORT);
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in))) {
String input;
while ((input = reader.readLine()) != null) {
if (input.equalsIgnoreCase("quit")) {
break;
}
if (input.equalsIgnoreCase("xu")) {
System.out.print("Enter username: ");
String username = reader.readLine();
out.println(username);
String response = in.readLine();
if (response.startsWith("register")) {
String[] parts = response.split("\"");
if (parts[1].equals("ok")) {
System.out.println("Registered successfully");
} else {
System.out.println("Registration failed: " + parts[3]);
}
} else {
System.out.println("Unexpected response: " + response);
}
} else {
out.println(input);
}
}
out.println("quit");
} catch (IOException e) {
System.err.println("Client error: " + e.getMessage());
}
}
}
```
这段代码演示了如何使用Java套接字实现一对多的聊天程序,其中:
- 服务器端监听客户端的连接请求,并处理注册请求和聊天消息。
- 客户端连接服务器并发送注册请求或聊天消息。
注意,这只是一个简单的示例程序,实际应用中可能需要更多的功能和错误处理。
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