我正在Windows XP上使用Eclipse编写Java程序。我有一个多进程模拟程序,使用ProcessBuilder 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端的代码,并让另一个正常运行。但是当我尝试同时运行它们时,一个客户端总会出现ConnectException:Connection refused: connect错误。似乎是哪一个客户端较慢时就会发生这种情况。我可以在启动服务器之后但在启动客户端之前暂停一下,netstat确认两个套接字都处于活动状态。这可能是什么原因呢?下面是一些简化的代码。
更新:根据评论,我已经编辑了代码,将服务器多线程处理在单个套接字上,但我仍然遇到了相同的问题。以下的代码反映了更改。看起来,其中一个客户端打开并关闭了套接字,而另一个则没有机会打开它。我可以在每个客户端的末尾添加暂停语句,使另一个客户端完成,但这只是一种解决方法,而不是真正的解决方案。那么现在真正的问题是,如何保持ServerSocket监听,直到我告诉它关闭?
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();