尝试将文件上传到服务器或从服务器下载文件时,我为服务器和客户端编写了相同的代码。
从服务器下载工作正常,文件中没有数据丢失,但是由于某种原因,在上载文件时,并不会传输所有数据。
例如,客户端上的文件大小小于服务器上的文件大小。然后,当它在服务器上打开时,并不是全部都存在(因为没有收到全部)
服务器:
算法:
从客户端获取消息
客户端告诉服务器它要发送文件(推送)
服务器读取放置文件的位置,然后从客户端接收文件
public static void GetClientMessage() {
while (true) {
try {
try {
try {
serverSocket = new ServerSocket(PORT_NUMBER);
} catch (IOException ex) {
System.out.println("GetClientMessage():serverSocket:IOException:ex " + ex);
SendBackException(ex.toString()); // Inform client
}
try {
System.out.println("Waiting for client");
socket = serverSocket.accept();
} catch (IOException ex) {
System.out.println("GetClientMessage():socket = serverSocket.accept():IOException:ex " + ex);
SendBackException(ex.toString()); // Inform client
}
bufOut = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
brffReadIn = new BufferedReader(new InputStreamReader(socket.getInputStream(), "UTF-8"));
// 1 - Read Line (it is the flag)
flag = brffReadIn.readLine();
// 2 - Handle Flag
HandleClientMessage(flag);
// Make decisions based upon that message
} catch (IOException ex) {
System.out.println("GetClientMessage():IOException:ex: " + ex);
SendBackException(ex.toString()); // Inform client
}
socket.close();
serverSocket.close();
} // Close while loop
catch (IOException ex) {
System.out.println("GetClientMessage:serverSocket.close():IOException:ex " + ex);
}
}
}
public static void HandleClientMessage(String message) {
System.out.println("HandleClientMessage:message: '" + message + "'");
switch (message) {
case "push":
GetClientFile();
break;
case "open_cla":
OpenCla();
break;
case "kill_cla":
KillCla();
break;
case "get":
SendFile();
break;
default:
break;
}
}
// Gets path to where to place file on local
public static String GetPath() {
String filePath = " ";
try {
bufOut = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
brffReadIn = new BufferedReader(new InputStreamReader(socket.getInputStream(), "UTF-8"));
filePath = brffReadIn.readLine();
System.out.println("Path to place file on local: " + filePath);
} catch (IOException ex) {
System.out.println(("GetPath():IOException:ex: " + ex));
}
return filePath;
}
public static void GetClientFile() {
// Get the location where to place the file on local
fileOnLocal = GetPath();
int count;
try {
File file = new File(fileOnLocal);
// Get the size of the file
long length = file.length();
byte[] bytes = new byte[16* 1024];
InputStream in = socket.getInputStream();
OutputStream out = new FileOutputStream(fileOnLocal);
while ((count = in.read(bytes)) > 0) {
System.out.println("strByteArray: " + strByteArray);
out.write(bytes, 0, count);
}
out.flush();
System.out.println("File Size in bytes: " + file.length());
if (file.length() < 5) {
System.out.println("FileClient:Error:File:" + fileOnLocal + " not found on server");
out.close();
in.close();
socket.close();
file.delete();
System.out.println("File:" + file.getAbsolutePath() + " deleted");
} else {
out.close();
in.close();
socket.close();
}
} catch (IOException ex) {
System.out.println(":FileClient:GetServerFile():IOException:ex:" + ex);
}
}
客户代码:
客户端告诉服务器它要“推送”文件,然后传递将其放置在服务器上的位置,然后传输文件
public void SendFlagToServer(String flag){
try {
bufOut = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
brffReadIn = new BufferedReader(new InputStreamReader(socket.getInputStream(), "UTF-8"));
bufOut.write(flag);
bufOut.newLine();
bufOut.flush();
System.out.println(host + ":SendFlagToServer: " + flag);
} catch (IOException ex) {
Logger.Log((host + ":FileClient:SendFileToGetToServer():IOException:ex: " + ex));
}
}
执行完此操作后,将在客户端上接收字节,但不是全部。我编码有误吗?我的byte []数组应该大小不同吗?将来将在Win7和Win8以及Mac上使用。
编辑:我想通了。我试图发送一条消息,后跟一串字节太快。
这解决了我的问题:
SendFlagToServer(fileLocaitonOnServer);
Thread.sleep(1000);
....
最佳答案
您在第一个客户端连接后关闭套接字
socket.close();
serverSocket.close();
解:
接受客户端套接字后,使用套接字连接创建一个新线程并处理该线程中的所有IO操作
不要关闭serverSocket。关闭serverSocket之后,将不再接受任何客户端套接字连接。
您能提供您得到的例外吗?
关于java - 在通过套接字传输文件后,为什么文件中的数据丢失了?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/32080381/