我正在尝试创建一个多线程双工聊天服务器。在将代码移入线程之前,我让它工作正常,但现在每当线程尝试访问套接字时,我都会收到“SocketException:套接字已关闭”。
我和老师都想不通。 (老师对 Java 的了解比我还少;他是 C 语言的)。看起来套接字是打开的,但一进入线程,它就关闭了。
我做错了什么?
客户端代码:
public class Client {
public static void main(String[] args) throws IOException {
String hostName = "localhost";
int portNumber = 6969;
try (
Socket socket = new Socket(hostName, portNumber);
) {
System.out.println("Chat connected");
//Sender
if (!socket.isClosed())
new Thread(new Sender(socket)).start();
//Receiver
if (!socket.isClosed())
new Thread(new Receiver(socket)).start();
} catch (SocketException e) {
System.out.println("Connection terminated unexpectedly");
}
}
}
服务器代码:
public class Server {
public static void main(String[] args) throws IOException {
int portNumber = 6969;
try (
ServerSocket serverSocket = new ServerSocket(portNumber);
Socket clientSocket = serverSocket.accept();
) {
//Receiver
if (!clientSocket.isClosed())
new Thread(new Receiver(clientSocket)).start();
//Sender
if (!clientSocket.isClosed())
new Thread(new Sender(clientSocket)).start();
} catch (Exception e) {
e.printStackTrace();
}
}
}
接收线程代码:
class Receiver implements Runnable {
private Socket socket;
Receiver(Socket s) throws IOException {
socket = s;
}
@Override
public void run() {
try (BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()))) {
String received;
do {
received = in.readLine();
if (received == null) break;
System.out.println("Them: " + received);
} while (!received.contains("/dropmic"));
} catch (IOException e) {
e.printStackTrace();
}
}
}
发送线程代码:
class Sender implements Runnable {
private Socket socket;
Sender(Socket s) throws IOException {
socket = s;
}
@Override
public void run() {
try (PrintWriter out = new PrintWriter(socket.getOutputStream(), true);
BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in))) {
String sent;
do {
System.out.print("You: ");
sent = stdIn.readLine();
if (sent == null) break;
out.println(sent);
} while (!sent.contains("/dropmic"));
} catch (IOException e) {
e.printStackTrace();
}
}
}
服务器输出:
java.net.SocketException: Socket is closed
at java.net.Socket.getOutputStream(Socket.java:943)
at Sender.run(Sender.java:16)
at java.lang.Thread.run(Thread.java:745)
java.net.SocketException: Socket closed
at java.net.SocketInputStream.socketRead0(Native Method)
at java.net.SocketInputStream.socketRead(SocketInputStream.java:116)
at java.net.SocketInputStream.read(SocketInputStream.java:170)
at java.net.SocketInputStream.read(SocketInputStream.java:141)
at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284)
at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326)
at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178)
at java.io.InputStreamReader.read(InputStreamReader.java:184)
at java.io.BufferedReader.fill(BufferedReader.java:161)
at java.io.BufferedReader.readLine(BufferedReader.java:324)
at java.io.BufferedReader.readLine(BufferedReader.java:389)
at Receiver.run(Receiver.java:19)
at java.lang.Thread.run(Thread.java:745)
Process finished with exit code 0
客户端输出(仍在运行):
Chat connected
You: java.net.SocketException: Socket is closed
at java.net.Socket.getInputStream(Socket.java:903)
at Receiver.run(Receiver.java:16)
at java.lang.Thread.run(Thread.java:745)
最佳答案
您正在使用 try-with-resources 语句,并将套接字作为资源。但是,当您创建新线程时,此 try-with-resources 到达其代码末尾并关闭套接字。将套接字放在实际的 try 语句中并手动关闭它们以解决此问题。
关于java - 套接字一进入新线程就关闭,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/36635595/