我正在尝试使用https://www.rgagnon.com/javadetails/java-0542.html中的代码来创建双向文件传输程序。我试图将代码的接收和发送代码分成各自的方法，并在服务器端调用send然后接收，在客户端调用receive然后发送。如果我仅以自己的方式进行传输，那么它可以工作，但是当我尝试进行一种传输时，使用另一个文件返回，则在最后一次传输完成之前将清除流。
这里是字段和main（）类TestServer {
public final static int SOCKET_PORT = 13267;
public final static String FILE_TO_RECEIVED = "D:\\TestFiles\\Client\\CFileReceived.txt";
public final static String FILE_TO_SEND = "D:\\TestFiles\\Client\\SFileToBeSent.txt";
// file size temporary hard coded should bigger than the file to be downloaded
public final static int FILE_SIZE = 6022386;
private static ServerSocket servsock = null; // used in main
private static Socket sock = null; // used in main
public static FileOutputStream fos = null; // used in receive
public static BufferedOutputStream bos = null; // used in receive
public static InputStream is = null; // used in receive
public static int bytesRead; // used in receive
public static int current = 0; // used in receive
private static FileInputStream fis = null; // used in send
private static BufferedInputStream bis = null; // used in send
private static OutputStream os = null; // used in send
private static InputStreamReader isr;
private static BufferedReader br;
public static void main(String[] args) throws IOException, InterruptedException {
try {
servsock = new ServerSocket(SOCKET_PORT); // creates servsock with socket port
while (true) {
System.out.println("Waiting...");
try {
sock = servsock.accept(); // accepts a socket connection
System.out.println("Accepted connection : " + sock);
os = sock.getOutputStream(); // sets Output Stream using the sockets output stream
is = sock.getInputStream(); // get input stream from socket
control("send");
control("receive");
} // end of try
finally {
// if any streams or sockets are not null, the close them
if (bis != null)
bis.close();
if (os != null)
os.close();
if (sock != null)
sock.close();
} // end of finally
} // end of while
} // end of try
finally {
if (servsock != null)
servsock.close();
} // end of finally
} // end of main
这里是字段和main（）类TestClient {
public final static int SOCKET_PORT = 13267; // you may change this
public final static String SERVER = "127.0.0.1"; // localhost
// you may change this, I give a different name because i don't want to
// overwrite the one used by server...
public final static String FILE_TO_RECEIVED = "D:\\TestFiles\\Client\\SFileReceived.txt";
public final static String FILE_TO_SEND = "D:\\TestFiles\\Client\\ClientCFileToBeSent.txt";
// file size temporary hard coded should bigger than the file to be downloaded
public final static int FILE_SIZE = 6022386;
public static Socket sock = null; // used in main
public static FileOutputStream fos = null; // used in receive
public static BufferedOutputStream bos = null; // used in receive
public static InputStream is = null; // used in receive
public static int bytesRead; // used in receive
public static int current = 0; // used in receive
private static FileInputStream fis = null; // used in send
private static BufferedInputStream bis = null; // used in send
private static OutputStream os = null; // used in send
private static PrintWriter pw;
public static void main(String[] args) throws IOException {
try {
sock = new Socket(SERVER, SOCKET_PORT);
System.out.println("Connecting...");
// get input and output from socket
is = sock.getInputStream(); // get input stream from socket
os = sock.getOutputStream(); // get output stream from socket
// receive file
control("receive");
control("send");
} // end of try
finally {
if (sock != null)
sock.close();
} // end of finally
} // end of main
这是服务器和客户端中的控件，接收和发送方法。
public static void control(String input) throws IOException {
switch (input) {
case "send":
sendFile(FILE_TO_SEND);
break;
case "receive":
receiveFile();
break;
case "end":
break;
default:
} // end of switch
} // end of control()
public static void sendFile(String filetosend) throws IOException {
File myFile = new File(filetosend); // creates a file using file to send path
byte[] mybytearray = new byte[(int) myFile.length()]; // creates a byte array the size of myFile
fis = new FileInputStream(myFile); // creates new FIS from myFile
bis = new BufferedInputStream(fis); // creates BIS with the FIS
bis.read(mybytearray, 0, mybytearray.length); // copies the BIS byte array into the byte array
// prints to console filename and size
System.out.println("Sending " + FILE_TO_SEND + "(" + mybytearray.length + " bytes)");
os.write(mybytearray, 0, mybytearray.length); // copies the byte array into the output stream therefore sending
// it through the socket
os.flush(); // flush/clears the output stream
System.out.println("Done.");
} // end of sendFile()
// ------------------------------------------------
public static void receiveFile() throws IOException {
byte[] mybytearray = new byte[FILE_SIZE]; // creates byte aray using file size
fos = new FileOutputStream(FILE_TO_RECEIVED); // creates file from path
bos = new BufferedOutputStream(fos); // creates BOS from FOS
bytesRead = is.read(mybytearray, 0, mybytearray.length); // assigns the input stream to
current = bytesRead; // equals the two integers for comparisons later
do { // no freaking clue
bytesRead = is.read(mybytearray, current, (mybytearray.length - current));
if (bytesRead >= 0)
current += bytesRead;
} while (bytesRead > -1);
bos.write(mybytearray, 0, current); // writes the byte array to the BOS therefore into the file
bos.flush(); // clears the buffer
// prints to the console the name and size of file
System.out.println("File " + FILE_TO_RECEIVED + " downloaded (" + current + " bytes read)");
} // end of receiveFile()
服务器的输出为：等候...接受的连接：套接字[地址= / 127.0.0.1，端口= 62815，本地端口= 13267]发送SFileToBeSent.txt（32字节）做完了Client的输出为：正在连接...
SFileReceived.txt和CFileReceived.txt均被创建，但其中没有任何内容。我对任何类型的InputStream和OutputStream都是新手，那么程序会出什么问题？非常感谢您的任何想法。
[首先，您的receiveFile方法应在循环中读取输入并写入输出。其次，请在完成后关闭文件，否则可能会导致资源泄漏。
公共静态无效的receiveFile（）抛出IOException {
byte[] mybytearray = new byte[FILE_SIZE]; // creates byte aray using file size
fos = new FileOutputStream(FILE_TO_RECEIVED); // creates file from path
bos = new BufferedOutputStream(fos); // creates BOS from FOS
int current = 0; // equals the two integers for comparisons later
try {
while ((bytesRead = is.read(mybytearray)) != -1) {
bos.write(mybytearray, 0, bytesRead );
current += bytesRead;
}
bos.flush(); // clears the buffer
System.out.println("File " + FILE_TO_RECEIVED + " downloaded (" + current + " bytes read)");
} finally {
bos.close();
}
}