【发布时间】：2012-04-16 21:24:35
【问题描述】：
我正在 Windows XP 上的 Eclipse 中编程 java。我有一个多进程模拟，它使用 ProcessBuilder 来运行一个服务器和两个客户端。服务器启动一个线程来监听两个不同的套接字 - 每个客户端一个。我可以注释掉每个客户的代码，让其他的工作完美无缺。当我尝试同时运行它们时，一个客户端总是会出现 ConnectException 错误：连接被拒绝：连接。它似乎是哪个客户端运行速度较慢，尽管很难说。我可以在启动服务器之后但在客户端之前暂停，并且 netstat 验证两个套接字都处于活动状态。这可能是什么原因造成的？我在下面有一些简化的代码。
更新：基于 cmets，我已经编辑了代码以在单个套接字上对服务器进行多线程处理，但我仍然遇到同样的问题。下面的代码反映了这些变化。似乎套接字正在由一个客户端打开和关闭，然后另一个客户端有机会打开它。我可以在每个客户端结束时抛出暂停语句，让另一个客户端完成，但这是一个修复，而不是解决方案。所以现在真正的问题是，我如何让 ServerSocket 一直监听直到我指示它关闭？
服务器
try{
server = new ServerSocket(sockNum);
} catch (IOException e) {
System.out.printf("Could not listen on port %d\n",sockNum);
System.exit(-1);
}
while(true){
ClientWorker w;
try{
Socket connection = server.accept();
w = new ClientWorker(connection);
Thread t = new Thread(w);
t.start();
} catch (IOException e) {
System.out.printf("Accept failed: %d\n",sockNum);
System.exit(-1);
}
}
class ClientWorker implements Runnable {
private Socket client;
ClientWorker(Socket client) {
this.client = client;
}
public void run(){
Object line;
ObjectInputStream in = null;
PrintWriter out = null;
try{
in = new ObjectInputStream(client.getInputStream());
out = new PrintWriter(client.getOutputStream(), true);
} catch (IOException e) {
System.out.println("in or out failed");
System.exit(-1);
}
while(true){
try{
line = in.readObject();
//Send data back to client
out.println("Sent from broker");
if(line instanceof String)
System.out.println(line);
else
System.out.println(line.getClass());
} catch (IOException e) {
System.out.println("Read failed");
System.exit(-1);
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
客户
try{
socket = new Socket("localhost", socketNum);
out = new ObjectOutputStream(socket.getOutputStream());
in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
out.writeObject(message);
String line = in.readLine();
System.out.println(line);
} catch (UnknownHostException e) {
System.out.println("Unknown host: localhost.eng");
System.exit(1);
} catch (IOException e) {
System.out.println("No I/O");
System.exit(1);
}
控制器
ProcessBuilder server = new ProcessBuilder("java.exe","-Xss64m","-cp","bin;jscheme.jar","ServerProcess");
server.redirectErrorStream(true);
Process runServer = server.start();
ProcessBuilder clientA = new ProcessBuilder("java.exe","-Xss64m","-cp","bin;jscheme.jar","ClientAProcess");
clientA.redirectErrorStream(true);
Process runClientA = clientA.start();
ProcessBuilder clientB = new ProcessBuilder("java.exe","-Xss64m","-cp","bin;jscheme.jar","ClientBProcess");
clientB.redirectErrorStream(true);
Process runClientB = clientB.start();
【问题讨论】：
标签： java multithreading sockets multiprocessing connectexception