Question

我目前正在尝试创建一个文件传输程序，可以将文件从一个位置传输到另一个位置。该程序适用于.txt文件，但对于其他扩展名，如.exe，传输的文件无法正常打开。任何人都可以通过我的代码发现问题？谢谢！

服务器代码：

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

public class SendFile{
    static ServerSocket receiver = null;
    static OutputStream out = null;
    static Socket socket = null;
    static File myFile = new File("C:\\Users\\hieptq\\Desktop\\AtomSetup.exe");
    /*static int count;*/
    static byte[] buffer = new byte[(int) myFile.length()];
    public static void main(String[] args) throws IOException{
        receiver = new ServerSocket(9099);
        socket = receiver.accept();
        System.out.println("Accepted connection from : " + socket);
        FileInputStream fis = new FileInputStream(myFile);
        BufferedInputStream in = new BufferedInputStream(fis);
        in.read(buffer,0,buffer.length);
        out = socket.getOutputStream();
        System.out.println("Sending files");
        out.write(buffer,0, buffer.length);
        out.flush();
        /*while ((count = in.read(buffer)) > 0){
            out.write(buffer,0,count);
            out.flush();
        }*/
        out.close();
        in.close();
        socket.close();
        System.out.println("Finished sending");



    }

}

客户代码：

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

public class ReceiveFile{
    static Socket socket = null;
    static int maxsize = 999999999;
    static int byteread;
    static int current = 0;
    public static void main(String[] args) throws FileNotFoundException, IOException{
        byte[] buffer = new byte[maxsize];
        Socket socket = new Socket("localhost", 9099);
        InputStream is = socket.getInputStream();
        File test = new File("D:\\AtomSetup.exe");
        test.createNewFile();
        FileOutputStream fos = new FileOutputStream(test);
        BufferedOutputStream out = new BufferedOutputStream(fos);
        byteread = is.read(buffer, 0, buffer.length);
        current = byteread;

        do{
            byteread = is.read(buffer, 0, buffer.length - current);
            if (byteread >= 0) current += byteread;
        } while (byteread > -1);
        out.write(buffer, 0, current);
        out.flush();

        socket.close();
        fos.close();
        is.close();

    }
}

Answer 1

一个问题是，在从InputStream读取时，您正在覆盖buffer的内容

    byteread = is.read(buffer, 0, buffer.length);
    current = byteread;

    do{
        byteread = is.read(buffer, 0, buffer.length - current);
        if (byteread >= 0) current += byteread;
    } while (byteread > -1);

InputStream #read将第二个param表示为偏移量，它将存储在字节数组中，在您的情况下，偏移量始终为0，因此它将在每次迭代中覆盖。

我建议简化从InputStream读取和写入OutputStream

的逻辑

byte[] buffer = new byte[16384];

while ((byteread = is.read(buffer, 0, buffer.length)) != -1) {
  out.write(buffer, 0, byteread);
}

out.flush();

希望这有帮助。

Java通过套接字发送和接收文件

1 个答案: