我正在学习 Java Socket
,我尝试开发一个 Socket
使用端口 80 从浏览器下载文件。
所以,我运行我的主类(下面的源代码),它将在我想要的任何端口中打开一个Socket
。
然后外部人员将访问 http://MY_IP:MY_PORT/download/FILE_NAME
我一切正常,但是客户端的文件大小为 0 字节(对于小文件),对于较大的存档,文件大小略小(原始 600mb,下载 540mb+-)
我确实检查了我的代码很多次,我找不到任何错误,我也从 java libs 更改为 Apache-commons 认为这会有所帮助,但没有成功。
所以也许我认为响应 header 有问题。
你们能帮帮我吗? 提前致谢。
类HTTPDownload
:
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
class HTTPDownloader {
Socket incoming = null;
ServerSocket server = null;
public HTTPDownloader(){
int port = 11000;
try{
server = new ServerSocket(port);
System.out.println("Creating SocketServer on Port " + port);
}catch(IOException e) {
e.printStackTrace();
System.exit(1);
}
System.out.println("Preparing to accept connections...");
while(true){
try{
incoming = server.accept();
System.out.println("connection!");
HTTPDownloaderThread thread1 = new HTTPDownloaderThread(incoming);
thread1.start();
}catch (Exception e) {
e.printStackTrace();
}
}
}
public static void main(String args[]) throws IOException{
new HTTPDownloader();
}
}
类HTTPDownloadThread
:
import java.io.File;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;
import java.net.SocketException;
import java.nio.file.Files;
import java.nio.file.Paths;
class HTTPDownloaderThread extends Thread {
private static final int BUFFER_SIZE = 4096;
private Socket socket;
private byte[] buf = new byte[BUFFER_SIZE];
private OutputStream out;
private InputStream is;
HTTPDownloaderThread(final Socket socket){
this.socket = socket;
}
public void run(){
int numberRead = 0;
try{
out = socket.getOutputStream();
is = socket.getInputStream();
numberRead = is.read(buf, 0, BUFFER_SIZE);
System.out.println("read " + numberRead);
if(numberRead<0)
return;
byte[] readBuf = new byte[numberRead];
System.arraycopy(buf, 0, readBuf, 0, numberRead);
String header = new String(readBuf);
System.out.println(header);
String fileName = header.split("\r\n")[0].split(" ")[1].substring(1);
System.out.println(socket.getInetAddress().getHostAddress()+" asked for file: "+fileName);
File f = new File("C:\\TestFolder\\"+fileName);
out.write("HTTP/1.1 200 OK\r\n".getBytes());
out.write("Accept-Ranges: bytes\r\n".getBytes());
out.write(("Content-Length: "+f.length()+"\r\n").getBytes());
out.write("Content-Type: application/octet-stream\r\n".getBytes());
out.write(("Content-Disposition: attachment; filename=\""+fileName+"\"\r\n").getBytes());
out.write("\r\n".getBytes()); // Added as Joy Rê proposed, make it work!
Files.copy(Paths.get("C:\\TestFolder\\"+fileName) , out);
System.out.println("File upload completed!");
// out.flush();
out.close();
socket.close();
}catch(SocketException e) {
System.out.println(e.getMessage());
}catch(Exception e){
e.printStackTrace();
}
}
}
最佳答案
一方面,在标题和数据之间添加另一个“\r\n”。检查您的 HTTP 响应; Content-Length header 是否报告了下载文件的正确文件大小?文件在客户端上显示的可用方式是否与在服务器上的使用方式相同? Web 代理总是有助于调试 HTTP(或其他客户端-服务器)应用程序:)
此外,我假设您在浏览器上指定端口 11000,因为这就是您在服务器上监听的端口
关于Java - 使用 Socket 通过浏览器下载文件,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/20844798/