java.net.SocketExceptionの対処法

Question

###質問内容
ソケットを使って，
名前，スコア，モード(easyかhardを数字で表したものの文字列)
をサーバーに送信しようと考えています．
ですが，実行しようとしてみたところ，Requester.sendScoreのshow ranking とコメントしたループのin.readLineが原因でjava.net.SocketException: Connection resetという例外が出てしまいました．
これはどのようにすれば解消できますか．

リンク内容
うえのようなサイトを見たところ範囲が広い例外のようで．調べてもあまり良くわかりませんでした．

###Requester

import java.net.*;
import java.util.*;
import java.io.*;

public class Requester extends Worker {
    //send score to server, show ranking
    public void sendScore(Player player){
        try {
            String name = player.getName();
            String score = String.valueOf(player.getScore());
            String mode =  String.valueOf(player.getMode());

            InetAddress addr = InetAddress.getByName("localhost");  // change for IP address
            Socket socket = new Socket(addr, 8080);   //set port No.
            PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())), true);
            out.println(name);     //send name
            out.println(score);    //send score
            out.println(mode);     //send mode

            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            
            //show ranking
            for(int i=0; i<6; i++){
                String str = in.readLine();
                System.out.println(str);
                Thread.sleep(1000);
            }

            socket.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}

###例外本文

java.net.SocketException: Connection reset
        at java.base/sun.nio.ch.NioSocketImpl.implRead(NioSocketImpl.java:323)
        at java.base/sun.nio.ch.NioSocketImpl.read(NioSocketImpl.java:350)
        at java.base/sun.nio.ch.NioSocketImpl$1.read(NioSocketImpl.java:803)
        at java.base/java.net.Socket$SocketInputStream.read(Socket.java:976)
        at java.base/sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:297)
        at java.base/sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:339)
        at java.base/sun.nio.cs.StreamDecoder.read(StreamDecoder.java:188)
        at java.base/java.io.InputStreamReader.read(InputStreamReader.java:178)
        at java.base/java.io.BufferedReader.fill(BufferedReader.java:161)
        at java.base/java.io.BufferedReader.readLine(BufferedReader.java:329)
        at java.base/java.io.BufferedReader.readLine(BufferedReader.java:396)
        at Requester.sendScore(Requester.java:55)
        at ClientMain.main(ClientMain.java:57)

###追記
Server側
updateRankingでスコアを受け取っています．

import java.net.*;
import java.util.*;
import java.util.Map.Entry;
import java.io.*;


public class Responser{
    private static ArrayList<String> Qstring = new ArrayList<>();  //question
    private static ArrayList<Long> timeList = new ArrayList<>();      //waiting list
    
    //accept score and register it to ranking
    public void updateRanking() throws IOException {
        ServerSocket s = new ServerSocket(8080); // make socket
        Socket socket = s.accept();  // wait setting demand of connection
        BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        String p_name = in.readLine();    //accept name
        String p_score = in.readLine();   //accept score
        int p_mode = Integer.parseInt(in.readLine());    //accept mode

        String rankingFilePath;
        if(p_mode == 1)    rankingFilePath = "data/ranking/easyranking.txt";
        else               rankingFilePath = "data/ranking/hardranking.txt";
        
        //key=ID, value=score
        Map<Integer,Integer> scores = new HashMap<Integer,Integer>();
        ArrayList<String> playerNameList = new ArrayList<String>();
        
        Scanner s2 = new Scanner(new File(rankingFilePath));
        int count = 1;
        
        int id = -1, score = -1;
        String name = "";
        while (s2.hasNext()){
            if(count % 3 == 1){
                id = Integer.parseInt(s2.next());
            }else if(count % 3 == 2){
                score = Integer.parseInt(s2.next());
            }else{
                name = s2.next();
                scores.put(id,score);
                playerNameList.add(name);
            }
            count++;
        }

        try{
            int nextId = playerNameList.size()+1;
            File file = new File(rankingFilePath);
            FileWriter filewriter = new FileWriter(file, true);
            filewriter.write(nextId + " " + p_score + " " + p_name + "\n");
            filewriter.close();
            scores.put(nextId, Integer.parseInt(p_score));
            playerNameList.add(p_name);
        }catch(IOException e){
            System.out.println(e);
        }

        // make entry list of scorelist
        List<Entry<Integer, Integer>> list_entries = new ArrayList<Entry<Integer, Integer>>(scores.entrySet());
        
        //sort scorelist
        Collections.sort(list_entries, new Comparator<Entry<Integer, Integer>>() {
            public int compare(Entry<Integer, Integer> obj1, Entry<Integer, Integer> obj2) {
                return obj2.getValue().compareTo(obj1.getValue());
            }
        });


        PrintWriter out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())), true);  //setting of sending buffer

        //send ranking data to client
        String[] ordinalNumber = {"1st", "2nd", "3rd", "4th", "5th"};
        out.println("--- Rank | Player | Score ---");
        for(int i=0; i<5; i++){
            out.println(ordinalNumber[i] + ", "  + playerNameList.get(list_entries.get(i).getKey()-1) + ", " + list_entries.get(i).getValue());
        }
        s.close();
    }

}

###ClientMain

import java.io.*;
import java.util.*;

public class ClientMain {
    public static void main(String[] args) throws InterruptedException{
        Player player = new Player("", 0, 0);  //(name, score, mdoe)
        GameData gameData = new GameData(player);
        ClientSystem clientsystem = new ClientSystem();
        Requester requester = new Requester();
        
        clientsystem.opening();  //op 

        clientsystem.say("Choose difficulty from easy:1 or hard:2.");
        clientsystem.say("Input the difficulty number.");
        Scanner scan = new Scanner(System.in);
        int difficulty = scan.nextInt();

        player.setMode(difficulty);
        requester.sendDifficulty(player);
        
        clientsystem.say("send difficulty");
        clientsystem.say("gamedata download...");
        Thread.sleep(1000);

        requester.requestGameData(gameData);  //download gamedata from server
        clientsystem.say("Load Successes!");
        Thread.sleep(2000);

        clientsystem.startGame(gameData);  //gamestart
        System.out.println();
        clientsystem.say("Finish");  
        
        clientsystem.showScore(player);  //show score

        
        clientsystem.say("Please input your name.");

        String playerName = scan.nextLine();
        scan.close();
        player.setName(playerName);
        
        requester.sendScore(player);  

        clientsystem.say("See you!");
    }
}

###実行本文

[Welcome to this TYPING GAME.]
[When this system says something, uses [] like this message]
[--rule--]
[Type the message enclosed in {}.]
[The next is a example.]
Q.{ もんだいぶん }
[if you misstype and enter without modifying, subtract your score.]
[There are two difficulty levels]
[Choose difficulty from easy:1 or hard:2.]
[Input the difficulty number.]
1
[send difficulty]
[gamedata download...]
[Load Successes!]
[Are you ready?]
[START!]
0

[Finish]
[Score: 0]
[Please input your name.]
--- Rank | Player | Score ---
java.net.SocketException: Connection reset
        すでに載せたので文字数の都合上割愛
[See you!]
PS C:\Users\Client>

###原因の推定
名前の入力をまたずに
--- Rank |
というものが出力されてしまっているので，
名前の入力をしようとしたときにupdateRankingがもう始まってしまっているのが原因だと考えられます．
本来ならこのupdateはsendScoreを待たなければいけないのに先に終わらせてしまっているからこのような例がでたと考えております．
updateRankingｇがしっかりと待機するようにするにはどうすればよいですか
文字数の都合上，必要ないと判断した関数は省略しました

Answer 1

クライアントが readLine する前にサーバの方が先にコネクションを切断しているのでは？

Comments

[akaevaka]

追記のほうにサーバー側の動きを載せたのですが，最後にcloseしているのでreadLineする前にコネクションを切断していない，と考えていたのですが，なにか順番がおかしいのでしょうか．

[akaevaka]

thread.sleepをいれて時間遅らせたら問題なくいけました

[sigsegv]

すでに質問が解決済みになりましたが、一応気になった点を。
サーバ側の最後に s.close() をしていますが、クライアントと通信しているソケットは socket なので、socket .close() も入れたほうがいいと思います。

[akaevaka]

ご指摘ありがとうございます，そのようにさせていただきます．
ありがとうございました．