Java-每行缺少第一个字母

我正在创建文件传输程序，将文件传输到客户端。但是当我传输文件时，它丢失了每行的第一个字母。我的代码怎么了

我对java相当陌生，所以我不知道下一步该做什么。我尝试更改字节大小，但没有帮助。我该怎么办

Server.java

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;

class Server {
    public static void main(String[] args) throws IOException {
        FileInputStream fis = null;
        BufferedInputStream bis = null;
        OutputStream os = null;
        ServerSocket serverSocket = null;
        Scanner scan = new Scanner(System.in);
        String fileSend;
        System.out.print("Type the path to the file to send >> ");
        fileSend = scan.nextLine();
        try {
            serverSocket = new ServerSocket(5467);
        } catch (Exception e) {
            System.out.println("Could not bind to port 5467, Maybe address is already is use or you need to run as administrator");
            return;
        }
        System.out.println("Listening on port 5467");
        System.out.println("Waiting for the connection...");
        while (true) {
            File FileSend = null;
            Socket socket = serverSocket.accept();
            OutputStream out = socket.getOutputStream();
            System.out.println("Accepted connection : " + socket);
            InputStream in = socket.getInputStream();
            DataInputStream dataIn = new DataInputStream(in);
            String login = dataIn.readUTF();
            String password = dataIn.readUTF();
            String result = "You credential is ";
            if (login.equals("1c18b5cdef8f9b4c5d6b2ad087265e597d1d4639337b73a04a335103c00ec64b") && password.equals("1c18b5cdef8f9b4c5d6b2ad087265e597d1d4639337b73a04a335103c00ec64b13d0b73358bfa8978dfaaf180565bcfecd3dc0631cda525920865145fb3fa131")) {
                result += "correct";
            } else {
                result += "incorrect";
            }
            DataOutputStream dataOut = new DataOutputStream(out);
            try {
                dataOut.writeUTF(result);
            } catch (FileNotFoundException e) {
                System.out.println("No such file or directory");
            }
            finally
            {
                FileSend = new File(fileSend);
                byte[] FileByteArray = new byte[(int) FileSend.length()];
                try {
                    fis = new FileInputStream(FileSend);
                }
                catch (FileNotFoundException e) {
                    System.out.println("No such file or directory");
                    return;
                }
                bis = new BufferedInputStream(fis);
                File myFile = new File (fileSend);
                byte [] mybytearray  = new byte [(int)myFile.length()];
                fis = new FileInputStream(myFile);
                bis = new BufferedInputStream(fis);
                bis.read(mybytearray,0,mybytearray.length);
                os = socket.getOutputStream();
                System.out.println("Sending " + fileSend + "(" + mybytearray.length + " bytes)");
                os.write(mybytearray,0,mybytearray.length);

                os.flush();
                System.out.println("Done.");
            }
        }
    }
}

Client.java

import java.io.*;
import java.net.*;
import java.nio.charset.StandardCharsets;
import java.util.Scanner;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class Client {
    public static void main(String[] args) throws IOException, NoSuchAlgorithmException {
        Socket socket = null;
        String PlainLogin;
        String FileOut;
        String PlainPassword;
        Scanner scan = new Scanner(System.in);
        System.out.print("What is the IP address of the server >> ");
        String host = scan.nextLine();
        try {
            socket = new Socket(host, 5467);
        } catch (ConnectException | NullPointerException e) {
            System.out.println("Connection Refused, Have you run the server first?");
            return;
        }

        OutputStream out = socket.getOutputStream();
        DataOutputStream dataOut = new DataOutputStream(out);
        InputStream is = socket.getInputStream();
        System.out.println("Connection Established");
        System.out.println("Credential Required, Please login");
        System.out.print("Type your username >> ");
        PlainLogin = scan.next();
        System.out.print("Type your password >> ");
        PlainPassword = scan.next();
        MessageDigest md = MessageDigest.getInstance("SHA-256");
        byte[] hashInBytes = md.digest(PlainLogin.getBytes(StandardCharsets.UTF_8));

        StringBuilder sb = new StringBuilder();
        for (byte b : hashInBytes) {
            sb.append(String.format("%02x", b));
        }
        String HashedLogin = sb.toString();

        byte[] hashInBytesP = md.digest(PlainPassword.getBytes(StandardCharsets.UTF_8));

        for (byte b : hashInBytesP) {
            sb.append(String.format("%02x", b));
        }
        String HashedPassword = sb.toString();
        dataOut.writeUTF(HashedLogin);
        dataOut.writeUTF(HashedPassword);

        InputStream in = socket.getInputStream();
        DataInputStream dataIn = new DataInputStream(in);
        String str = dataIn.readUTF();
        if (str == "Your credential is incorrect") {
            System.out.println(str);
            return;
        } else {
            System.out.print("Type any file name you want >> ");
            scan.nextLine();
            FileOut = scan.nextLine();

            OutputStream output = new FileOutputStream(FileOut);
            byte[] mybytearray = new byte[1024];
            is.read(mybytearray, 0, mybytearray.length);
            int bytesRead;
            byte[] buffer = new byte[1024];
            while ((bytesRead = in.read(buffer)) > 0) {
                output.write(buffer, 0, bytesRead);
            }
            output.close();
            socket.close();
            dataIn.close();
            System.out.println("Done");
            return;
        }
    }
}

---

我希望它像“Java”一样显示全文，但它只显示“ava”

文件是可序列化的，所以我建议您只需尝试直接通过ObjectOutputStream/ObjectInputStream发送它

例如，在服务器端：

ObjectInputStream in = new ObjectInputStream(socket.getInputStream());
ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
...
out.writeObject(yourFileObject);

和客户：

ObjectInputStream in = new ObjectInputStream(socket.getInputStream());
ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
...
File receivedFile = null;
try {
    receivedFile = (File) in.readObject();
}
catch (IOException e) {
...
}

---

文件是可序列化的，所以我建议您只需尝试通过ObjectOutputStream/ObjectInputStream直接发送它

例如，在服务器端：

ObjectInputStream in = new ObjectInputStream(socket.getInputStream());
ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
...
out.writeObject(yourFileObject);

和客户：

ObjectInputStream in = new ObjectInputStream(socket.getInputStream());
ObjectOutputStream out = new ObjectOutputStream(socket.getOutputStream());
...
File receivedFile = null;
try {
    receivedFile = (File) in.readObject();
}
catch (IOException e) {
...
}

我不完全清楚为什么会发生这种情况，但您不应该使用

DataInputStream

which“”，而应该使用

InputStreamReader

which“”

此外，您还可以将该读取器包装到一个

BufferedReader

中，它允许您逐行读取，最后您将得到如下内容

try (BufferedReader reader=new BufferedReader(new InputStreamReader(inStream, UTF8));
     PrintWriter writer = new PrintWriter(file)) {
    reader.lines().forEach(writer::println);
}

用于上传，或

try (PrintWriter writer = new PrintWriter(outStream)) {
    Files.lines().forEach(writer::println);
}

下载。

我不完全清楚为什么会发生这种情况，但您不应该使用

DataInputStream

which“”，而应该使用

InputStreamReader

which“”

此外，您还可以将该读取器包装到一个

BufferedReader

中，它允许您逐行读取，最后您将得到如下内容

try (BufferedReader reader=new BufferedReader(new InputStreamReader(inStream, UTF8));
     PrintWriter writer = new PrintWriter(file)) {
    reader.lines().forEach(writer::println);
}

用于上传，或

try (PrintWriter writer = new PrintWriter(outStream)) {
    Files.lines().forEach(writer::println);
}

---

下载。

您也发送UTF编码的数据吗？我的猜测是，第一个字节被视为BOM并被吃掉。查看传入的原始字节数据是否与来自服务器的传出数据匹配。请在（（bytesRead=in.read（buffer））>=0的情况下尝试此in循环{您也发送UTF编码的数据吗？我的猜测是第一个字节被视为BOM并被吃掉。查看传入的原始字节数据是否与服务器传出的数据匹配。在（（bytesRead=in.read（buffer））>=0的情况下在循环中尝试此操作{