为文件传输输入时出错

Question

我的任务是通过socket发送文件。我提示要发送多少个文件。但它总是扔exception.

这是代码：

public void soc_server() throws IOException {
    servsock = new ServerSocket(55000);
    sock = servsock.accept();
    System.out.println("Hello Server");
    Scanner sc = new Scanner(System.in);
    **System.out.println("how many files to be sent: ");
    String temp = sc.nextLine();
    // i used to take integer here. Still it was throwing same exception.
    int fileNumber = Integer.parseInt(temp);
    sc.close();
    sc = new Scanner(System.in);**
    for (int x = 0; x < fileNumber; x++) {
        System.out.println("Please enter the file name or file path ");
        String s = sc.nextLine();
        File file = new File(s);
        if (file.exists())
            System.out.println("File found");
        else
            System.out.println("File not found");
        OutputStream out = sock.getOutputStream();
        fileInputStream = new FileInputStream(s);
        byte[] buffer = new byte[100 * 1024];
        int bytesRead = 0;
        System.out.println("sending file no: " + x);
        while ((bytesRead = fileInputStream.read(buffer)) != -1) {
            if (bytesRead > 0) {
                out.write(buffer, 0, bytesRead);
                totalSent += bytesRead;
                System.out.println("sent " + (totalSent / 1024) + " KB "
                        + ((System.currentTimeMillis() - time) / 1000)
                        + " sec");
            }
        }
        out.flush();
        fileInputStream.close();
        // sock.close();
        out.close();
        // servsock.close();
        // servsock = new ServerSocket(55000);
        // sock = servsock.accept();
        pw = new PrintWriter(sock.getOutputStream(), true);
        pw.print(s);
        pw.flush();
        pw.close();
    }
    sock.close();
    servsock.close();
    sc.close();
    System.out.println("Sent " + (totalSent / 1024) + " kilobytes in "
            + ((System.currentTimeMillis() - time) / 1000) + " seconds");
}

例外：

Exception in thread "main" java.util.NoSuchElementException: No line found
at java.util.Scanner.nextLine(Scanner.java:1585)
at Server.soc_server(Server.java:41)
at Index.main(Index.java:21)

除了要发送多少文件的提示行外，其余代码运行良好。我真的很困惑为什么我在写作时会遇到相同的异常：

String temp = sc.nextLine();
int fileNumber = sc.nextInt();

谢谢。

Answer 1

在代码开头分配扫描程序：删除以下行

    sc.close();
    sc = new Scanner(System.in);