捕獲異常后如何恢復/重新啟動Java中的線程？

Question

最近，我一直在嘗試使用Java的Networking and Threading功能，就像我試圖開發多線程聊天應用程序的背景一樣。

問題是，當客戶端發送使用錯誤格式的消息時，例如：“ UserID＃Message”而不是“ UserID * Message”，將引發異常，線程將完全停止，客戶端需要關閉其會話並重新打開再次重新建立與服務器的連接，而不是在錯誤發生后恢復連接，而我無法恢復它。

這是服務器代碼：

package AdvanceThreading.Server;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;

public class Server {

    private ServerSocket serverSocket;
    private Socket socket;

    private DataInputStream messageFromClientToHandler;
    private DataOutputStream messageFromHandlerToRecipient;

    private int port;
    private static int userID;
    private ArrayList<ClientHandler> clientList;

    public Server(int port) {
        this.port = port;
        this.userID = 0;
        clientList = new ArrayList<>();
        this.initialize();
    }

    public void initialize() {
        try {
            serverSocket = new ServerSocket(port);
        } catch (IOException e) {
            e.printStackTrace();
        }

        while (true) {
            try {
                socket = serverSocket.accept();

                messageFromClientToHandler = new DataInputStream(socket.getInputStream());
                messageFromHandlerToRecipient = new DataOutputStream(socket.getOutputStream());

                String userName = messageFromClientToHandler.readUTF();

                messageFromHandlerToRecipient.writeInt(userID);

                ClientHandler client = new ClientHandler(userID, userName, this, socket, messageFromClientToHandler, messageFromHandlerToRecipient);

                clientList.add(client);

                //Should set client.setUncaughtExceptionHandler();

                client.start();

                userID = userID + 1;

            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    public ServerSocket getServerSocket() {
        return serverSocket;
    }

    public Socket getSocket() {
        return socket;
    }

    public DataInputStream getMessageFromClientToHandler() {
        return messageFromClientToHandler;
    }

    public DataOutputStream getMessageFromHandlerToRecipient() {
        return messageFromHandlerToRecipient;
    }

    public int getPort() {
        return port;
    }

    public static int getUserID() {
        return userID;
    }

    public ArrayList<ClientHandler> getClientList() {
        return clientList;
    }

    public static void main(String[] args) {
        Server server = new Server(5050);
    }
}

客戶端處理程序代碼：

package AdvanceThreading.Server;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.util.StringTokenizer;

public class ClientHandler extends Thread {

    private int clientID;
    private String clientName;
    private boolean loggedIn;

    private Socket socket;

    private Server server;

    private DataInputStream messageFromClientToHandler;
    private DataOutputStream messageFromHandlerToRecipient;


    public ClientHandler(int clientID, String clientName, Server server, Socket socket, DataInputStream messageFromClientToHandler, DataOutputStream messageFromHandlerToRecipient) {
        this.clientID = clientID;
        this.clientName = clientName;
        this.loggedIn = true;
        this.server = server;
        this.socket = socket;
        this.messageFromClientToHandler = messageFromClientToHandler;
        this.messageFromHandlerToRecipient = messageFromHandlerToRecipient;
    }

    @Override
    public void run() {

        String receivedFromClient;
        StringTokenizer tokenize = null;

        while (true) {
            try {
                receivedFromClient = messageFromClientToHandler.readUTF();

                System.out.println(receivedFromClient);

                tokenize = new StringTokenizer(receivedFromClient, "#");
                String recipient = tokenize.nextToken();
                int recipientID = Integer.parseInt(tokenize.nextToken());
                String message = tokenize.nextToken();

                //Need to handle exception of client not found.

                for (ClientHandler client : server.getClientList()) {
                    if (client.getClientID() == recipientID && client.isLoggedIn()) {
                        client.getMessageFromHandlerToRecipient().writeUTF(this.clientName + ": " + message);
                        break;
                    }
                }
            } catch (IOException e) {
                while (tokenize != null && tokenize.hasMoreTokens())
                    tokenize.nextToken();

                e.printStackTrace();
            }
        }
    }

    public String getClientName() {
        return clientName;
    }

    public void setClientName(String clientName) {
        this.clientName = clientName;
    }

    public boolean isLoggedIn() {
        return loggedIn;
    }

    public void setLoggedIn(boolean loggedIn) {
        this.loggedIn = loggedIn;
    }

    public int getClientID() {
        return clientID;
    }

    public Socket getSocket() {
        return socket;
    }

    public Server getServer() {
        return server;
    }

    public DataInputStream getMessageFromClientToHandler() {
        return messageFromClientToHandler;
    }

    public DataOutputStream getMessageFromHandlerToRecipient() {
        return messageFromHandlerToRecipient;
    }
}

我要執行的主要操作是：如果使用終端的客戶端（Ex：CMD）發生錯誤，我想捕獲該錯誤，並在同一終端上恢復其會話，從而不必重新連接到該終端。服務器再次。

Answer 1

根據討論，您可以使用RuntimeException捕獲任何無效的相關數據專有名詞：

  StringTokenizer tokenize = new StringTokenizer(receivedFromClient, "#");

        try {
            String recipient = tokenize.nextToken();

            int recipientID = Integer.parseInt(tokenize.nextToken());
            String message = tokenize.nextToken();
        } catch (RuntimeException e) {

            //ask client to resend the data
            continue
        }