Question

我无法将文件上传到服务器。服务器收到文件，但一旦发送文件就不会停止接收。如何让它只收到一次？我怀疑我所包含的部分服务器代码有问题，希望有人能够识别问题=（

以下是代码。

Client.java

 System.out.println("These are the files available on the Server: \n");
String line = null;
while ((line = get1.readLine()) != null) {
    System.out.println(line);

}
int ans1;
Scanner scan = new Scanner(System.in);

System.out.println("\n1.Upload a file \n2.Download file \n");
int ans = scan.nextInt();
put.print(ans);
put.flush();
ans1 = ans;



switch(ans1){
    case 1:
        System.out.println("Name the file u wanna upload\n");
        String n=rd.readLine();
        put.println(n);
        n ="Client\\"+n;
//            System.out.println("Requesting "+n);
            //physical source path is added to the name of file 
                File files=new File(n);
                //open the file requested by client on the server machine 
                if(files.exists()){ 
                BufferedInputStream di=new BufferedInputStream(new FileInputStream(n));
                //creates a buffer stream to read bytes from the file 
                BufferedOutputStream outStream = new BufferedOutputStream(s.getOutputStream());
                //create a buffer stream to send bytes to the client socket
                byte buffer[] = new byte[1024];
                // creates a buffer to read from the file
                int read;
                while((read = di.read(buffer))!=-1){

            outStream.write(buffer, 0, read);
            outStream.flush();
            //while file is not finished it reads bytes from the file and send it to the client server
        }
            s.close();
            }
        break;


    case 2:
        String u,f;
        System.out.println("Enter the file name to download from server:");
        DataInputStream dis=new DataInputStream(System.in);
        f=dis.readLine();
        //it reads the name of file from the user
        put.println(f);
        //it sends the name of requested file to the server machine
        File f1=new File("Client\\"+f);
        //it creates a file with the same name in the physical path given on the client machine
        FileOutputStream  fs=new FileOutputStream(f1);
        //it creates an output stream to write bytes to the file
        BufferedInputStream d=new BufferedInputStream(s.getInputStream());
        //it creates buffer to receive data from server machine
        BufferedOutputStream outStream = new BufferedOutputStream(new FileOutputStream(f1));
        //it creates a buffer to write buffer of bytes to the file
        byte buffer[] = new byte[1024];
        int read;
        while((read = d.read(buffer))!=-1){
        outStream.write(buffer, 0, read);
        outStream.flush();
        //while the input buffer is not finished it reads the input sent by the server and writes it on the file created in the client machine
        }
        fs.close();
        //file is closed
        System.out.println("File received");
        s.close();
        //socket is closed
        System.out.println("wanna cont?");
        int yn = scan.nextInt();
        if(yn == 1){

        }
            break;
    case 3:
        System.out.println("exit");
        break;
}


}

Server.java

 if(num == 49){
        while(true)
            {
               String t=st.readLine();
               put.println(t);
                //it sends the name of requested file to the server machine
               System.out.println("the file will be receiving is "+t);
               File f1=new File("Server\\"+t);
                //it creates a file with the same name in the physical path given on the client machine
                FileOutputStream  fs=new FileOutputStream(f1);
                //it creates an output stream to write bytes to the file
                BufferedInputStream d=new BufferedInputStream(cs.getInputStream());
                //it creates buffer to receive data from server machine
                BufferedOutputStream outStream = new BufferedOutputStream(new FileOutputStream(f1));
                //it creates a buffer to write buffer of bytes to the file
                byte buffer[] = new byte[1024];
                int read;
                while((read = d.read(buffer))!=-1){
                outStream.write(buffer, 0, read);
                outStream.flush();
                //while the input buffer is not finished it reads the input sent by the server and writes it on the file created in the client machine
                }
                fs.close();
                //file is closed
                System.out.println("File received");
                cs.close();
                //socket is closed
                ss.close();
                s2.close();

@Dakkaron这里是服务器代码的前面部分

ServerSocket ss=null;

    try{
        ss=new ServerSocket(8081);
    } catch(IOException e){ 
        System.out.println("couldn't listen");
        System.exit(0);
    }
    Socket cs=null;
    try{ 
        cs=ss.accept();
        System.out.println("Connection established"+cs);
    } catch(Exception e){ 
        System.out.println("Accept failed");
        System.exit(1);
    }
    PrintWriter put=new PrintWriter(cs.getOutputStream(),true);
    BufferedReader st=new BufferedReader(new InputStreamReader(cs.getInputStream()));

Answer 1

开头的注释：请正确格式化代码，以便更容易阅读。大多数IDE都具有相当不错的自动格式功能。请在粘贴代码之前使用它。

现在问你的问题：我看到你的服务器在if之后直接有一个无限的while循环。从您发布的代码片段中，这是我看到的最大问题。因此，一旦完成接收第一个文件，它就会通过while循环循环到下一个文件。

尝试删除服务器代码开头的while（true），看看是否能解决问题。

客户端/服务器系统从客户端上传到服务器不准确

1 个答案: