Question about file uploads

Question

is having a file upload function on a web page a hard thing to do?
i need to do this, but i do not know where to start...
if anyone can help me out/shed some light on this for me that would be greatly appreciated!~!!!
THANKS!

Answer 1

No it is not particularly difficult; I let the user select a file on the client filesystem then upload to the server.
The form ENCTYPE must be multipart/form-data:
<FORM NAME="frmUpload" ENCTYPE="multipart/form-data" METHOD="POST" ACTION=...>
Use:
<INPUT TYPE="file" NAME="srcFile" SIZE="15" MAXLENGTH="40">
In my servlet:
verify:
String contentType = request.getHeader("Content-Type");
if (contentType.indexOf("multipart/form-data") < 0)     {
...handle error...
String boundary = contentType.substring(contentType.indexOf("boundary=") + 9, contentType.length());
private boolean TransferFile(ServletInputStream is, String srcFile,
String destDir,String caseNo, String boundary, String errorPage,
HttpServletRequest request, HttpServletResponse response) throws ServletException
File pathName = new File(...);
// If the target directory does not already exist then create it.
if (!pathName.exists()) {
pathName.mkdir();
if (!pathName.exists()) {  // did mkdir work?
... do lots more checking ...
boolean xferOK = false;
try {
FileOutputStream fout = new FileOutputStream(...);
byte[] nextBytes = null;
byte[] currBytes = null;
while ((nextBytes = ReadLine(is)) != null) {
if (currBytes != null) {
String snippet = "";
if (nextBytes.length - 10 <= boundary.length())
snippet = new String(nextBytes);
if (snippet.indexOf(boundary) < 0)
fout.write(currBytes, 0, currBytes.length);
else
fout.write(currBytes, 0, currBytes.length - 2);
currBytes = nextBytes;
fout.close();
xferOK = true;
catch (IOException ioe) {
return xferOK;
} // TransferFile()
Hope this helps