Can I close the connection after sending immediately on the server?

Question

I have a C/S program. On the server side, the process as following:
1. accept (blocking)
2. //a connection is established
using a new socket to receive request data from client
3. business processing ... (maybe several seconds)
4. send response data to client
5. close socket immediately
6. listening continuely again
The server side is running on linux and writed by Java, and client is running on windows and writed by C++ Builder.
My problem is:
1. if the server is running on windows, everything is OK.
2. if the server is running on linux (that is exprcted), the client can not receive the response data from server, the client program said the connection is unavailable when he read from socket blockingly.
3. if I add some delay, e.g. 500ms, between sending response and close the connection, the client can receive response normally.
why above?
thanks for help.
Jack

Answer 1

Sorry, long time to go away.
package test.server;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;
public class EchoServer {
     private int port; // listened port
     private ServerSocket ssock; // the server's ip
     public EchoServer(String host, int port) {
          this.port = port;
          // Create a ServerSocket
          try {
               ssock = new ServerSocket(port);
               SocketAddress addr = new InetSocketAddress(host, port);
               ssock.bind(addr);
          } catch (Exception ex) {
               ex.printStackTrace();
          new HandleThread().start();
     public class HandleThread extends Thread {
          public int ntohl(byte[] bytes, int offset) {
               int length1 = ((((int) bytes[offset + 0]) << 24) & 0xff000000);
               int length2 = ((((int) bytes[offset + 1]) << 16) & 0x00ff0000);
               int length3 = ((((int) bytes[offset + 2]) << 8) & 0x0000ff00);
               int length4 = ((((int) bytes[offset + 3]) << 0) & 0x000000ff);
               return length1 + length2 + length3 + length4;
          public void run() {
               InputStream in = null;
               OutputStream out = null;
               try {
                    while (true) {
                         System.out.println("Start Listening...  [" + port + "]");
                         Socket clisock = ssock.accept();
                         //clisock.setSoLinger(true, 1);
                         System.out.println( "SOLinger:" + clisock.getSoLinger());
                         try {
                              System.out.println("Accepted Client Socket...  [" + clisock + "]");
                              in = clisock.getInputStream();
                              out = clisock.getOutputStream();
                              // receive four bytes length
                              byte[] lenbuff = new byte[4];
                              in.read(lenbuff, 0, 4);
                              int len = ntohl(lenbuff, 0);
                              byte[] buff = new byte[len];
                              in.read(buff, 0, len);
                              System.out.println("Received length&#65306;" + len + "  " + new String(buff));
                              Thread.sleep(1000);
                              out.write(lenbuff);
                              out.write(buff);
                              out.flush();
                              //Thread.sleep(500);
                              System.out.println("Send finished&#12290;");
                         } catch (Exception ex) {
                              ex.printStackTrace();
                         } finally {
                              if (in != null) {
                                   try {
                                        in.close();
                                   } catch (Exception ex) {
                              if (out != null) {
                                   try {
                                        out.close();
                                   } catch (Exception ex) {
                              if (clisock != null) {
                                   try {
                                        long time00 = System.currentTimeMillis();
                                        clisock.close();
                                        System.out.println( "close socket&#65306;[" + (System.currentTimeMillis() - time00) + "]");
                                   } catch (Exception ex) {
               } catch (Exception ex) {
                    ex.printStackTrace();
     public static void main(String[] args) throws Exception {
          if( args.length == 2 ) {
               new EchoServer(args[0], Integer.parseInt(args[1]));
          } else if( args.length == 2 ) {
               new EchoServer("127.0.0.1", Integer.parseInt(args[0]));
          } else {
               new EchoServer("127.0.0.1", 16000);
}In my application, the package is following:
length(4bytes) + data
I have a simple WinSocket Client, send data to this server and receive the response,the sending is OK, Server can receive all messages.But when client is ready to receive data, the winsock call return WSAECONNRESET(10054).
If I uncomment "Thread.sleep(500);", it means wait some time before close socket, the client can receive all response data.
why?