我尝试使用以下代码在两台计算机之间发送文件：
类FileSender：
import java.io.OutputStream;
import java.io.File;
import java.net.Socket;
public class FileSender {
// host and port of receiver
private static final int port = 4700;
private static final String host = "localhost";
public static void main(String[] args) {
try {
Socket socket = new Socket(host, port);
OutputStream os = socket.getOutputStream();
int cnt_files = 1;
// How many files?
ByteStream.toStream(os, cnt_files);
for (int cur_file = 0; cur_file < cnt_files; cur_file++) {
ByteStream.toStream(os, "test.txt");
ByteStream.toStream(os, new File("test.txt"));
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
类FileReceiver：
import java.io.File;
import java.io.InputStream;
import java.net.Socket;
import java.net.ServerSocket;
import java.util.ArrayList;
import java.util.StringTokenizer;
public class FileReceiver implements Runnable {
private static final int port = 4700;
private Socket socket;
public static void main(String[] _) {
try {
ServerSocket listener = new ServerSocket(port);
while (true) {
FileReceiver file_rec = new FileReceiver();
file_rec.socket = listener.accept();
new Thread(file_rec).start();
}
} catch (java.lang.Exception ex) {
ex.printStackTrace(System.out);
}
}
public void run() {
try {
InputStream in = socket.getInputStream();
int nof_files = ByteStream.toInt(in);
for (int cur_file = 0; cur_file < nof_files; cur_file++) {
String file_name = ByteStream.toString(in);
StringTokenizer st = new StringTokenizer(file_name, "\\");
ArrayList<String> strings = new ArrayList<String>();
while (st.hasMoreElements()) {
strings.add(st.nextToken().toString());
}
System.out.println("c:\\Users\\acer5635\\Documents\\" + strings.get(0));
File file = new File("c:\\Users\\acer5635\\Documents\\" + strings.get(0));
ByteStream.toFile(in, file);
}
} catch (java.lang.Exception ex) {
ex.printStackTrace(System.out);
}
}
}
类ByteStream：
import java.io.InputStream;
import java.io.OutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileInputStream;
public class ByteStream {
private static byte[] toByteArray(int in_int) {
byte a[] = new byte[4];
for (int i = 0; i < 4; i++) {
int b_int = (in_int >> (i * 8)) & 255;
byte b = (byte) (b_int);
a[i] = b;
}
return a;
}
private static int toInt(byte[] byte_array_4) {
int ret = 0;
for (int i = 0; i < 4; i++) {
int b = (int) byte_array_4[i];
if (i < 3 && b < 0) {
b = 256 + b;
}
ret += b << (i * 8);
}
return ret;
}
public static int toInt(InputStream in) throws java.io.IOException {
byte[] byte_array_4 = new byte[4];
byte_array_4[0] = (byte) in.read();
byte_array_4[1] = (byte) in.read();
byte_array_4[2] = (byte) in.read();
byte_array_4[3] = (byte) in.read();
return toInt(byte_array_4);
}
public static String toString(InputStream ins) throws java.io.IOException {
int len = toInt(ins);
return toString(ins, len);
}
private static String toString(InputStream ins, int len) throws java.io.IOException {
String ret = new String();
for (int i = 0; i < len; i++) {
ret += (char) ins.read();
}
return ret;
}
public static void toStream(OutputStream os, int i) throws java.io.IOException {
byte[] byte_array_4 = toByteArray(i);
os.write(byte_array_4);
}
public static void toStream(OutputStream os, String s) throws java.io.IOException {
int len_s = s.length();
toStream(os, len_s);
for (int i = 0; i < len_s; i++) {
os.write((byte) s.charAt(i));
}
os.flush();
}
private static byte[] toByteArray(InputStream ins, int an_int) throws
java.io.IOException,
Exception {
byte[] ret = new byte[an_int];
int offset = 0;
int numRead = 0;
int outstanding = an_int;
while ((offset < an_int)
&& ((numRead = ins.read(ret, offset, outstanding)) > 0)) {
offset += numRead;
outstanding = an_int - offset;
}
if (offset < ret.length) {
throw new Exception("Could not completely read from stream, numRead="
+ numRead + ", ret.length=" + ret.length); // ???
}
return ret;
}
private static void toFile(InputStream ins, FileOutputStream fos, int len, int buf_size) throws
java.io.FileNotFoundException,
java.io.IOException {
byte[] buffer = new byte[buf_size];
int len_read = 0;
int total_len_read = 0;
while (total_len_read + buf_size <= len) {
len_read = ins.read(buffer);
total_len_read += len_read;
fos.write(buffer, 0, len_read);
}
if (total_len_read < len) {
toFile(ins, fos, total_len_read, buf_size / 2);
}
}
private static void toFile(InputStream ins, File file, int len) throws
java.io.FileNotFoundException,
java.io.IOException {
FileOutputStream fos = new FileOutputStream(file);
toFile(ins, fos, len, 1024);
}
public static void toFile(InputStream ins, File file) throws
java.io.FileNotFoundException,
java.io.IOException {
int len = toInt(ins);
toFile(ins, file, len);
}
public static void toStream(OutputStream os, File file)
throws java.io.FileNotFoundException,
java.io.IOException {
toStream(os, (int) file.length());
byte b[] = new byte[1024];
InputStream is = new FileInputStream(file);
int numRead = 0;
while ((numRead = is.read(b)) > 0) {
os.write(b, 0, numRead);
}
os.flush();
}
}
我首先启动了FileReceiver。 在 FileSende 类中，当我输入host =“localhost”时;该计划工作正常。 但是当我尝试从另一台计算机发送文件时（在我启动 FileSende.java之前，我将执行 FileReceiver.java 的地址设置为host =“192.168.1.2”==＆gt; IP） ）我遇到了这个例外：
java.net.SocketException: Connection reset
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at ByteStream.toInt(ByteStream.java:35)
at ByteStream.toString(ByteStream.java:44)
at FileReceiver.run(FileReceiver.java:41)
at java.lang.Thread.run(Unknown Source)
两台计算机中的防火墙已关闭（两台计算机的操作系统均为Windows 7 32位。）
答案 0 :(得分：2)
在终止发送程序之前，您需要确保接收方已完全接收文件。
您可以让收件人在收到文件后发送确认，并在发件人中等待该确认。
在您的情况下，更简单的方法是在发送文件后调用Socket.shutdownOutput()。
在您的FileSender中：
for (int cur_file = 0; cur_file < cnt_files; cur_file++) {
ByteStream.toStream(os, "test.txt");
ByteStream.toStream(os, new File("test.txt"));
}
socket.shutdownOutput();