我创建了一个从有权访问的FTP服务器下载文件的功能。如何将文件上传回FTP服务器？
以下是我使用的download_files方法：
public static void download_files(String un, String pw, String ip, String dir, String fn, String fp){
URLConnection con;
BufferedInputStream in = null;
FileOutputStream out = null;
try{
URL url = new URL("ftp://"+un+":"+pw+"@"+ip+"/"+dir+"/"+fn+";type=i");
con = url.openConnection();
in = new BufferedInputStream(con.getInputStream());
out = new FileOutputStream(fp+fn);
int i = 0;
byte[] bytesIn = new byte[1024];
while ((i = in.read(bytesIn)) >= 0) {
out.write(bytesIn, 0, i);
}
}catch(Exception e){
System.out.print(e);
e.printStackTrace();
System.out.println("Error while FTP'ing "+fn);
}finally{
try{
out.close();
in.close();
}catch(IOException e){
e.printStackTrace();
System.out.println("Error while closing FTP connection");
}
}
}