Thursday, December 27, 2012

Upload file using JSP

I found a good article to upload a file using jsp here . I just modified it little so that it can upload file to the root directory of the webapp.


<%@ page language="java" %>
<HEAD><TITLE>Display file upload form to the user</TITLE></HEAD>
<% // for uploading the file we used Encrypt type of multipart/form-data and input of file type to browse and submit the file %>
<BODY> <FORM ENCTYPE="multipart/form-data" ACTION="single_upload_page.jsp" METHOD=POST>
<center><table border="2" >
<tr><center><td colspan="2"><p align="center"><B>PROGRAM FOR UPLOADING THE FILE</B><center></td></tr>
<tr><td><b>Choose the file To Upload:</b></td>
<td><INPUT NAME="F1" TYPE="file"></td></tr>
<tr><td colspan="2"><p align="right"><INPUT TYPE="submit" VALUE="Send File" ></p></td></tr>


<%@ page import="*" %>
//to get the content type information from JSP Request Header
String contentType = request.getContentType();
//here we are checking the content type is not equal to Null and as well as the passed data from mulitpart/form-data is greater than or equal to 0
if ((contentType != null) && (contentType.indexOf("multipart/form-data") >= 0)) {
DataInputStream in = new DataInputStream(request.getInputStream());
//we are taking the length of Content type data
int formDataLength = request.getContentLength();
byte dataBytes[] = new byte[formDataLength];
int byteRead = 0;
int totalBytesRead = 0;
//this loop converting the uploaded file into byte code
while (totalBytesRead < formDataLength) {
byteRead =, totalBytesRead, formDataLength);
totalBytesRead += byteRead;

String file = new String(dataBytes);
//for saving the file name
String saveFile = file.substring(file.indexOf("filename=\"") + 10);
saveFile = saveFile.substring(0, saveFile.indexOf("\n"));
saveFile = saveFile.substring(saveFile.lastIndexOf("\\") + 1,saveFile.indexOf("\""));
int lastIndex = contentType.lastIndexOf("=");
String boundary = contentType.substring(lastIndex + 1,contentType.length());
int pos;
//extracting the index of file
pos = file.indexOf("filename=\"");
pos = file.indexOf("\n", pos) + 1;
pos = file.indexOf("\n", pos) + 1;
pos = file.indexOf("\n", pos) + 1;
int boundaryLocation = file.indexOf(boundary, pos) - 4;
int startPos = ((file.substring(0, pos)).getBytes()).length;
int endPos = ((file.substring(0, boundaryLocation)).getBytes()).length;

// creating a new file with the same name and writing the content in new file
FileOutputStream fileOut = new FileOutputStream(getServletContext().getRealPath("") +saveFile);
fileOut.write(dataBytes, startPos, (endPos - startPos));

%><Br><table border="2"><tr><td><b>You have successfully upload the file by the name of:</b>
<% out.println(saveFile); %></td></tr></table> <%

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