为什么我的Java服务器关闭套接字？

问题描述

我有服务器和客户端。
我的服务器保护所有连接并返回客户端字符串。
但是当我尝试发送更多行时，它会崩溃

I have server and client.My server acepts all connections and returns to client string.But when I try to send more lines its crashed with

java.net.SocketException：Socket关闭
at java.net.Socket.getOutputStream（未知来源）
at server.ServerCore.hiMsg（ServerCore.java:67）
at server.ServerCore.run（ServerCore.java:49）

这是我的服务器代码：

package server;

import java.io.File;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.*;
import java.util.Vector;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author pisio
 */
public class ServerCore extends Thread {

    private LoadSettings loadSettings = LoadSettings.Init();
    private int port = loadSettings.getConfigInt("port");
    private int max_connections = loadSettings.getConfigInt("max_connections");
    private String ipServer = loadSettings.getConfig("ipServer");
    private ServerSocket socket;
    private Socket connection;
    private boolean serverRuning = false;
    private int connectedUsers = 0;
    private Vector connVector = new Vector();

    @Override
    public void run() {

        try {
            socket = new ServerSocket(port, max_connections);
            System.out.println("+++\t Server was started at  address:" + socket.getLocalSocketAddress() + " with posible max users " + max_connections);

            serverRuning = true;

            while (serverRuning) {
                if (connectedUsers <= max_connections) {
                    connection = socket.accept();
                    connection.setKeepAlive(serverRuning);
                    connVector.add(connection);
                    connectedUsers = connVector.size();
                    hiMsg();
                    hiMsg();
                    hiMsg();

                }

                System.out.println("+++\t Last User:" + connVector.get(connVector.size() - 1).toString());
            }


        } catch (IOException ex) {
            //   Logger.getLogger(ServerCore.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public void hiMsg() {

        try {
            Socket c = (Socket) connVector.get(connVector.size() - 1);
            PrintWriter out = new PrintWriter(new OutputStreamWriter(c.getOutputStream()));
            out.write("Hi user !  Im server !  Your master !  Blow me down\nping: ?  PONG ?");
            out.close();

        } catch (IOException ex) {
            Logger.getLogger(ServerCore.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public void stopServer() {
        statusServer();
        serverRuning = false;
        try {
            socket.close();
        } catch (IOException ex) {
            //Logger.getLogger(ServerCore.class.getName()).log(Level.SEVERE, null, ex);
        }
        System.out.println("+++++\t  SERVER WAS STOPED !");
        // System.exit(port);

    }

    public void statusServer() {
        if (serverRuning) {
            System.out.println("Server running at port:" + port + "  with connected users :" + connectedUsers + "/" + max_connections);
        } else {
            System.out.println("Server IS NOT RUNNING!");
        }
    }
}

这是我的客户代码：

package meetingsclient;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.lang.String;
import java.net.Socket;
import java.util.logging.Level;
import java.util.logging.Logger;

public class ServerConnect {

    private static ServerConnect sc = null;
    private Socket socket = null;

    private ServerConnect() {

        try {
            socket = new Socket("localhost", 8080);

            sendHiMsg();

        } catch (Exception ex) {
            Logger.getLogger(ServerConnect.class.getName()).log(Level.SEVERE, null, ex);
        }

    }

    private void sendHiMsg() throws IOException {
        BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));


        System.out.println("Input:" + in.readLine());


    }

    public static ServerConnect Init() {
        if (sc == null) {
            sc = new ServerConnect();
        }
        return ServerConnect.sc;
    }
}

我读了这个主题：但这个dotn帮助了我。
//很抱歉这些链接，但我不明白如何正确格式化我的代码。

I readed this topic : Socket Exception: socket is closed but this dotn helped me.// Sorry for the links , but I cant understand how properly to format my code here.

推荐答案

来自：

From the javadoc of getOutputStream() in Socket:

此外，关闭 PrintWriter （和所有其他打印机/写入器也关闭其底层流。因此，您将关闭 PrintWriter （在 hiMsg（）中关闭 OutputStream code>）然后尝试写入已关闭的套接字。

Also, closing a PrintWriter (and all other Printers/Writers) close their underlying streams as well. So, you are closing your OutputStream by closing the PrintWriter (in hiMsg()) and then trying to write to the socket, which was closed.

要解决此问题，请不要关闭 PrintWriter的。垃圾收集将为您照顾它！但是当你完成它时，请关闭套接字。

To fix the problem, don't close the PrintWriter. Garbage collection will take care of it for you! But do close the socket when you are done with it.

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