java - 如何让服务器以多行响应？ ( java )

Question

我想从文件中获取文本，然后将其发送到服务器以使其大写，然后再发送回打印输出的客户端。我该如何实现这一目标？

我可以读取一行并将其发送回客户端，并且我已设法将多行写入输出流(供服务器读取)，但我不知道现在该怎么办..

我有一个从文件中读取文本的客户端:

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

public class Client 
{
    public static void main(String[] args)
    {
        try
        {
            // First create the input from keyboard
            BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
            System.out.println("Client Program");

            // Next we need to find out the IP address and port number of the server
            System.out.print("Enter IP Address of server: ");
            String ip = input.readLine();
            System.out.print("Enter port number of server: ");
            String port_string = input.readLine();

            // The port number needs to be an int, so convert the string to an int
            int port = Integer.parseInt(port_string);

            // Connect to the server
            Socket sock = new Socket(ip, port);


            // Create the incoming stream to read messages from
            DataInputStream network = new DataInputStream(sock.getInputStream());

            //Create the output stream to the client
            DataOutputStream message = new DataOutputStream(sock.getOutputStream());

            //Send message
            //message.writeUTF("some text");
            FileReader file = new FileReader("text.dat");
            BufferedReader input_file = new BufferedReader(file);

            // Loop until EOF
            while (input_file.ready()){
            // Read next line from the file
                String line = input_file.readLine();
                // Write line to server
                message.writeUTF(line + "\n");
                //System.out.println(line);
            }

            // Display our address
            System.out.println("Address: " + sock.getInetAddress());
            String line;

            // Loop until the connection closes, reading from the network
            while ((line = network.readUTF()) != null)
            {
                // Display the received message
                System.out.println(line);
            }
        }
        catch (IOException ioe)
        {
            // This is expected when the server closes the network connection
            System.err.println("Error in I/O");
            System.err.println(ioe.getMessage());
            System.exit(-1);
        }
    }
}

然后服务器应该接受这些字符串并将它们大写:

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

public class Server 
{
    public static void main(String[] args)
    {
        try
        {
            // First create the input from the keyboard
            BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
            System.out.println("Server Program");

            // Get the port to listen on
            System.out.print("Enter port number to listen on: ");
            String port_string = input.readLine();

            // The port number needs to be an int, so convert the String to an int
            int port = Integer.parseInt(port_string);

            // Create a ServerSocket to listen on this address
            ServerSocket server = new ServerSocket(port);

            // Accept an incoming client connection on the server socket
            Socket sock = server.accept();

            // Create the output stream to the client
            DataOutputStream network = new DataOutputStream(sock.getOutputStream());

            //Create the incoming stream to read messages from
            DataInputStream message =  new DataInputStream(sock.getInputStream());



            String newLine = inFromClient.readLine();

            //Line to read
            String line;
            line = message.readUTF();
            line = line.toUpperCase();




            // Send message
            network.writeUTF(newLine);

            // Close sockets.  This will cause the client to exit
            sock.close();
            server.close();
        }
        catch (IOException ioe)
        {
            System.err.println("Error in I/O");
            System.err.println(ioe.getMessage());
            System.exit(-1);
        }
    }
}

Answer 1

问题是您的服务器仅读取一次流并关闭套接字连接。您的服务器如何知道您已完成将客户端数据发送到服务器套接字？您应该修改服务器以监听端口，直到发送完整个文本。为此，请执行以下操作 -

String newLine;
while ( true )
newLine = inFromClient.readLine();              
          if (newLine.equalsIgnoreCase("END"))
{
    break;
}

          newLine = newLine.toUpperCase();                 

// Send message             
          network.writeUTF(newLine);
}
// Close sockets.  This will cause the client to exit

sock.close();               
server.close();

在发送完所有行后，从客户端发送“END”。