java - TCP 不写入完整文件？

Question

我正在尝试使用一个程序将一个文本文件写入多个套接字。用于覆盖文本文件的代码如下:

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

public class Server {
    public static void main(String args[]) throws Exception{
        String servers[] = {"127.0.0.1","127.0.0.1","127.0.0.1"};
        int[] ports = {4525, 4003,3621};
        String fileName = "example";

        for(int i = 0; i < servers.length; i++){
            getFile(fileName, InetAddress.getByName(servers[i]), ports[i], "1");
        }
    }
    public static void getFile(String fileName, InetAddress ia, int port, String vers) throws Exception{
        Socket myServers = new Socket(ia, port);
        PrintWriter pwSoc = new PrintWriter(myServers.getOutputStream(), true);
        pwSoc.println(fileName + " " + "write " + vers);
        InputStream is = null;
        int i =0;
        while(i < 20000){
            i++;
        }
        int c;
        try{
            is = new FileInputStream(fileName + ".txt");
        }
        catch(Exception e){
            System.out.println("Error. This file is not found"); 
            return;
        }
        while ((c = is.read()) != -1) {
            pwSoc.println((char)c); 
            pwSoc.flush();
        }
        pwSoc.close();
        is.close();
        pwSoc.close();
        return;
    }
}

然后，在服务器端(对于所有三台服务器)，我使用以下线程，其计算结果为 else if(req.equals("write")){ 代码块:

import java.io.*;
import java.net.*;
import java.util.StringTokenizer;
public class ServerRequestThread implements Runnable{ //Server 1
    Socket client;
    File[] files;
    VersionInfo vi;
    public ServerRequestThread(Socket s, VersionInfo vi) throws Exception{
        this.client = s;
        String filePath = new File(".").getCanonicalPath();
        this.files = new File(filePath).listFiles();
        this.vi = vi;
    }

    public void run() {
        String req = "", reversedString = "";
        try {
            while(true){
                InputStream in = client.getInputStream();
                BufferedReader bin = new BufferedReader(new InputStreamReader(in));
                String ex = bin.readLine();
                StringTokenizer st = new StringTokenizer(ex, " ");
                String fileName = st.nextToken();
                if(fileName.equals("done")){
                    return;
                }
                else if(fileName.equals("fileList")){
                    String returnList = showFiles(files).trim();
                    PrintWriter pout = new PrintWriter(client.getOutputStream(), true);
                    pout.println(returnList);
                    pout.close();
                }
                else if(fileName.equals("filecatchup")){
                    PrintWriter pout = new PrintWriter(client.getOutputStream(), true);
                    pout.println(vi.printHash());
                    pout.close();
                }
                else{
                    req = st.nextToken();
                }
                if(req.equals("read")){
                    PrintWriter pout = new PrintWriter(client.getOutputStream(), true);
                    int c;
                    InputStream is = null;
                    try{
                        is = new FileInputStream(fileName + ".txt");
                    }
                    catch(Exception e){
                        pout.println("File could not be found");
                        return;
                    }
                    while ((c = is.read()) != -1) {
                        pout.println((char)c); 
                    }
                    pout.close();
                    return;
                }
                else if(req.equals("write")){
                    if(st.hasMoreTokens()){
                        String vers = st.nextToken();
                        vi.updateHash(fileName, Integer.parseInt(vers));
                        System.out.println("The file " + fileName + " was updated  (via remote update) to v." + vers);
                    }
                    else{
                        vi.updateFile(fileName);
                        System.out.println("The file " + fileName + " was updated to v." + vi.getFile(fileName));
                    }

                    InputStream in2 = client.getInputStream();
                    BufferedReader reader = new BufferedReader(new InputStreamReader(in2));
                    reversedString = reader.readLine();


                    PrintWriter out = new PrintWriter(fileName + ".txt");
                    while(reversedString != null){
                        //cont+=reversedString;
                        out.print(reversedString);
                        reversedString = reader.readLine();
                    }
                    reader.close();
                    out.close();
                    return;
                }
            }
        } catch (Exception e) {}
    }
    public String showFiles(File[] files) throws Exception {
        String ret = "";
        //System.out.println("Path: " + new File(".").getCanonicalPath());
        for (File file : files) {
            if (file.isDirectory()) {
                //System.out.println("Directory: " + file.getName());
                showFiles(file.listFiles()); // Calls same method again.
            } else { 
                if(file.getName().toLowerCase().endsWith(".txt")){
                     ret+= " "  + file.getName();
                }
            } 
        } 
        return ret;
    } 

}

出于某种原因，当我写入时，整个文件并没有传到另一端。相反，我错过了文件前 100 个字节左右的某个地方。例如，如果我写 Lorem Ipsum 文本，我将在第一句话周围的某个地方丢失。

有人知道为什么会这样吗？我几乎尝试了所有方法，但似乎无法解决问题

Answer 1

您首先创建一个 BufferedReader bin 并使用它来读取命令的一行。但是，这并不意味着只有这一行是从输入流中读取的。取而代之的是读取更多字节，但 BufferedReader bin 只返回这些字节的第一行，其余部分保存在 BufferedReader 的缓冲区内(这就是名称的原因!) .

稍后您尝试读取有效载荷，而不是使用阅读器 bin 您已经创建了一个新的 reader 并从中读取。通过这种方式，您可以忽略任何已在 bin 中缓冲的字节 - 这意味着您丢失了字节。