Simple FIle Upload Using JSP
This program only allows upload of html files which can be customised to upload files of any type by changing the if (contentType.equals("text/html")) appropriately
The uploaded file is saved in C:\ drive as demo.html

//upload.jsp a form to select the file to be uploaded
<form action="uploader.jsp" enctype="multipart/form-data" method="POST">
<input type="file" name="myFile">
<input title="Upload selected file to the current working directory" type="Submit" class="button" name="Submit" value="Upload">
</form>
//uploader.jsp
<% @ page import="java.util.*,java.text.*,java.io.*, java.io.IOException, java.rmi.RemoteException, javax.servlet.http.HttpServletRequest "%>
<%
class uploadThis
{
public String upLoadFile(HttpServletRequest request) throws IOException, RemoteException, Exception {
int lineSize = 128;
String userAgent="";
String fileName="";
String newLine=new String();
String contentType="";
FileOutputStream fs2=null;
PrintStream fs=null;
try {
ServletInputStream in = request.getInputStream();
byte[] line = new byte[256];
int inDex = 0;
int i = in.readLine(line, 0, 256);
int boundaryLength=i-2;
String boundary = new String(line, 0,i-2);
while (i != -1)
{
if (newLine.startsWith("Content-Disposition: form-data; name=\"")) //begining of the file
{
if (newLine.indexOf("filename=\"") != -1)
{
//check if the name of file is there in the stream
fileName = newLine.substring(newLine.trim().lastIndexOf("\"", newLine.trim().length() - 2), newLine.length()).replaceAll("\"", "");
userAgent+= boundary+"hey got the file name "+fileName+"
"+"c:/"+fileName;
fs2 = new FileOutputStream("c:/demo.html");
fs = new PrintStream(fs2);
}
}
if (newLine.startsWith("Content-Type")) //get the content type from the stream
{
newLine = newLine.replaceAll("Content-Type: ", "");
userAgent+="got the content Type "+newLine.trim()+"
";
contentType=newLine.trim();
i = in.readLine(line, 0, 256);
newLine = new String(line, 0, i);
}

if (contentType.equals("text/html"))
{
if ((new String(line, 0, i).startsWith(boundary)))
{ //End of File this boundary is a staret and end of a document uploaded its more or less like this -----------------------------265001916915724 (some random number)
fs.close();
}
else {
if (!newLine.trim().equals(""))
{
fs.print(newLine.substring(0,newLine.length()).trim()+"");
}
}
}
i = in.readLine(line, 0, 256);
newLine = new String(line, 0, i);
}
}
catch(Exception e){}
return userAgent;
}
}
%>
<%
out.write (System.getProperty("java.io.tmpdir")+"
");
uploadThis up = new uploadThis();
out.write (up.upLoadFile(request));
%>
Simple FIle Upload Using JSP