代码(java,多线程)在一行代码后停止执行
问题描述:
我试图用Java构建一个聊天服务器客户端程序。但问题是,在代码中的一个点之后,它会停止执行,并且对于我来说,我无法弄清楚原因。我在这里附上代码。我是新来的多线程和套接字编程,所以这可能是错误很明显,但我完全错过了它。代码(java,多线程)在一行代码后停止执行
public class ChatClient implements Runnable
{ private Socket socket = null;
private Thread thread1 = null;
private ObjectOutputStream streamOut = null;
private ChatClientThread client = null;
private Message sendMsg = null;
private String username = null;
private DataInputStream console = null;
private Scanner s = new Scanner(System.in);
String text;
public ChatClient(String serverName, int serverPort)
{ System.out.println("Establishing connection. Please wait ...");
try
{ socket = new Socket(serverName, serverPort);
System.out.println("Connected: " + socket);
System.out.println("Enter your username:");
username = s.nextLine();
start();
}
catch(UnknownHostException uhe)
{ System.out.println("Host unknown: " + uhe.getMessage()); }
catch(IOException ioe)
{ System.out.println("Unexpected exception: " + ioe.getMessage()); }
}
public void run()
{ while (thread1 != null)
{ try
{ sendMsg = new Message();
sendMsg.setMsg(s.nextLine());
System.out.println(sendMsg.getMsg()+ " check");
streamOut.writeObject(sendMsg);
streamOut.flush();
}
catch(IOException ioe)
{ System.out.println("Sending error: " + ioe.getMessage());
stop();
}
}
}
public void handle(String user, Message msg)
{ System.out.println("1");
if (msg.getMsg().equals(".bye"))
{ System.out.println("Good bye. Press RETURN to exit ...");
stop();
}
else
System.out.println(msg.getMsg());
System.out.println("Msg received");
}
public void start() throws IOException
{
//console = new DataInputStream(System.in);
System.out.println("1");
streamOut = new ObjectOutputStream(socket.getOutputStream());
System.out.println("3");
if (thread1 == null)
{ client = new ChatClientThread(this, socket, username);
System.out.println("Started new ChatClientThread");
thread1 = new Thread(this);
thread1.start();
}
else
System.out.println("This code is stupid.");
}
public void stop()
{ if (thread1 != null)
{ thread1.stop();
thread1 = null;
}
try
{ if (console != null) console.close();
if (streamOut != null) streamOut.close();
if (socket != null) socket.close();
}
catch(IOException ioe)
{ System.out.println("Error closing ..."); }
//client.close();
client.stop();
}
public static void main(String args[])
{ ChatClient client = null;
//if (args.length != 2)
// System.out.println("Usage: java ChatClient host port");
//else
client = new ChatClient("localhost", 2008);
}
}
所以它的工作是这样的,它的主要功能开始,去构造,发生在用户名和一切,继续开始()。我假设开始工作,因为它打印1 & 3,但在此之后,我继续输入文本,但它不会进入下一个点(我知道,因为它不打印“开始新的ChatClientThread”)。 任何帮助,将不胜感激。我一直在研究这段代码几个小时,而我只是无法弄清楚为什么执行停在那里。
UPDATE
我编辑的ChatClient.start代码
public void start() throws IOException
{
//console = new DataInputStream(System.in);
System.out.println("1");
streamOut = new ObjectOutputStream(socket.getOutputStream());
System.out.println("3");
if (thread1 == null)
{
System.out.println("Started new ChatClientThread");
client = new ChatClientThread(this, socket, username);
System.out.println("Started new ChatClientThread");
thread1 = new Thread(this);
thread1.start();
}
else
System.out.println("This code is stupid.");
}
我现在知道,它确实运行ChatClientThread的构造函数:
public ChatClientThread(ChatClient _client, Socket _socket, String uname)
{ System.out.println("Constructor started");
client = _client;
socket = _socket;
username = uname;
System.out.println("1");
open();
System.out.println("2");
start();
System.out.println("3");
}
它打印1 ,继续到ChatClientThread.open:
public void open()
{ try
{ streamIn = new ObjectInputStream(socket.getInputStream());
}
catch(IOException ioe)
{ System.out.println("Error getting input stream: " + ioe);
client.stop();
}
}
但是这里又是卡住的地方。它不会继续打印2,所以我认为它不会移动到ChatClientThread.start的一段代码。
答
好的,我刚刚阅读了常见问题解答,可以回答你自己的问题。所以在这里。
找到的解决方案:ObjectInputStream(socket.getInputStream()); does not work
答
您已覆盖start()
方法。请勿覆盖'start()
'方法。 如果您覆盖start()
方法,请不要忘记在方法结束时调用super.start()
。
start()
方法将启动run()
。
有关更多信息,请参阅this question和this answer。
ChatClientThread的代码在哪里? – 2012-02-05 08:49:55
作为参考,这里有一个工作[示例](http://*.com/a/3245805/230513)。 – trashgod 2012-02-05 08:51:47
此外,从构造函数中启动线程也是不好的做法。构建您的客户端,然后启动它。但我不明白为什么你需要在这里分开线程。为什么不在主线程中做所有事情?你有没有在Thread.stop()上看到过大的弃用警告? – 2012-02-05 08:54:09