Question

我正在使用jsp开发一个Web应用程序，其中我使用tcp connection将文件从服务器发送到客户端。但在这样做时，程序进入无限循环。它没有返回任何东西。有人可以帮帮我吗？

我在这里发布服务器和客户端代码。

服务器代码：

byte[] sendData = new byte[1024];
byte[] receiveData = new byte[1024];
sendData = "FILE".getBytes();
DatagramPacket sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, 5006);
clientSocket.send(sendPacket);
sendData = file.getBytes();
sendPacket = new DatagramPacket(sendData, sendData.length, IPAddress, 5006);
clientSocket.send(sendPacket);

ServerSocket serverSocket = new ServerSocket(5494);
Socket socket = serverSocket.accept();

File transferFile = new File("C:\\Users\\Krishna\\Documents\\LanMan\\" + file);
byte[] bytearray = new byte[(int) transferFile.length()];
FileInputStream fin = new FileInputStream(transferFile);
BufferedInputStream bin = new BufferedInputStream(fin);
bin.read(bytearray, 0, bytearray.length);
OutputStream os = socket.getOutputStream();
os.write(bytearray, 0, bytearray.length);

DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
clientSocket.receive(receivePacket);
String a = (new String(receiveData, "UTF-8")).trim();
//if(a.equals())
os.flush();
//bin.close();
socket.close();
serverSocket.close();

客户代码：

if (a.startsWith("FILE")) {
    byte b[] = new byte[1024];

    received = new DatagramPacket(receiveData, receiveData.length);
    serversocket.receive(received);
    a = (new String(receiveData, "UTF-8")).trim();

    int filesize = 2022386;
    int bytesRead;
    int currentTot = 0;
    socket = new Socket(ip, 5494);
    byte[] bytearray = new byte[filesize];
    InputStream is = socket.getInputStream();
    FileOutputStream fos = new FileOutputStream("C:\\LanMan\\" + a);
    BufferedOutputStream bos = new BufferedOutputStream(fos);
    bytesRead = is.read(bytearray, 0, bytearray.length);
    currentTot = bytesRead;

    do {
        bytesRead = is.read(bytearray, currentTot, (bytearray.length - currentTot));
        if (bytesRead >= 0) currentTot += bytesRead;
    } while (bytesRead > -1);

    bos.write(bytearray, 0, currentTot);
    bos.flush();
    bos.close();
    //fos.close();
    //is.close();

    sendData = "OK".getBytes();
    DatagramPacket send = new DatagramPacket(sendData, sendData.length, ip, port);
    serversocket.send(send);
    socket.close();
}

Answer 1

您实施了死锁。

服务器写入文件内容，然后等待来自客户端的数据报包，关闭套接字。

客户端读取，直到服务器关闭套接字，然后发送数据报包。

所以各方都在等待另一方。

此外，永远不要忽略InputStream.read（）方法的结果，就像在服务器代码中一样。您永远不能假设所有文件都将在一次调用中被读取。

在java中使用tcp传输文件时出错

1 个答案: