Upload and download file

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July 3, 2009 at 2:05 PM

Hi Friend,

Try the following code to upload the word document file:

1)page.jsp

<%@ page language="java" %>
<Html>
<HEAD><TITLE>Display file upload form to the user</TITLE></HEAD>

<BODY>
<FORM ENCTYPE="multipart/form-data" ACTION="upload.jsp" METHOD=POST>
<br><br><br>
<center><table border="2" >
<tr><center><td colspan="2"><p align="center"><B>UPLOAD THE FILE</B><center></td></tr>
<tr><td><b>Choose the file To Upload:</b>
</td>
<td><INPUT NAME="file" TYPE="file"></td></tr>
<tr><td colspan="2">
<p align="right"><INPUT TYPE="submit" VALUE="Send File" ></p></td></tr>
<table>
</center>
</FORM>
</BODY>
</HTML>

2)upload.jsp

<%@ page import="java.io.*" %>
<%@ page import="java.sql.*" %>

<%
String contentType = request.getContentType();
if ((contentType != null) && (contentType.indexOf("multipart/form-data") >= 0)) {
DataInputStream in = new DataInputStream(request.getInputStream());
int formDataLength = request.getContentLength();
byte dataBytes[] = new byte[formDataLength];
int byteRead = 0;
int totalBytesRead = 0;
while (totalBytesRead < formDataLength) {
byteRead = in.read(dataBytes, totalBytesRead,formDataLength);
totalBytesRead += byteRead;
}
String file = new String(dataBytes);
String saveFile = file.substring(file.indexOf("filename=\"") + 10);
saveFile = saveFile.substring(0, saveFile.indexOf("\n"));
saveFile = saveFile.substring(saveFile.lastIndexOf("\\") + 1,saveFile.indexOf("\""));
out.println(saveFile);
int lastIndex = contentType.lastIndexOf("=");
String boundary = contentType.substring(lastIndex + 1,contentType.length());
int pos;
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;

FileOutputStream fileOut = new FileOutputStream(saveFile);
fileOut.write(dataBytes, startPos, (endPos - startPos));
fileOut.flush();
fileOut.close();

%><Br><table border="2"><tr><td><b>You have successfully upload the file by the name of:</b>
<% out.println(saveFile);%></td></tr></table>
<%
Connection connection = null;
String connectionURL = "jdbc:mysql://192.168.10.112:3306/file";;;
ResultSet rs = null;
PreparedStatement psmnt = null;
FileInputStream fis;
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
connection = DriverManager.getConnection(connectionURL, "root", "root");
File f = new File(saveFile);
psmnt = connection.prepareStatement("insert into file(file_data) values(?)");
fis = new FileInputStream(f);
psmnt.setBinaryStream(1, (InputStream)fis, (int)(f.length()));
int s = psmnt.executeUpdate();
if(s>0) {
System.out.println("Uploaded successfully !");
}
else {
System.out.println("unsucessfull to upload file.");
}
}
catch(Exception e){e.printStackTrace();}
}
%>

July 3, 2009 at 2:06 PM

continue.........

Now to download the word document file, try the following code:

<%@page import="java.sql.*"%>
<%@page import="java.io.*"%>
<%@page import="javax.servlet.*"%>
<%
ServletOutputStream output = response.getOutputStream();
String connectionURL = "jdbc:mysql://192.168.10.112:3306/file";;;;;
String Content=new String("");
try{
Class.forName("com.mysql.jdbc.Driver").newInstance();
Connection con=DriverManager.getConnection(connectionURL,"root","root");
Statement st=con.createStatement();
ResultSet rst= st.executeQuery("select file_data from file where id=25 ");
if(rst.next())
{
Content=rst.getString("file_data");
}
con.close();
}catch(Exception e){
System.out.println("Exception caught"+e.getMessage());
}
byte requestBytes[] = Content.getBytes();
ByteArrayInputStream bis = new ByteArrayInputStream(requestBytes);
response.reset();
response.setContentType("application/doc");
response.setHeader("Content-disposition","attachment; filename=" +"file.doc");
byte[] buf = new byte[1024];
int len;
while ((len = bis.read(buf)) > 0){
output.write(buf, 0, len);
}
bis.close();
response.getOutputStream().flush();
%>

Thanks

July 9, 2009 at 3:17 PM

I want to download a file from a database but before downloading a file, server should ask me the destination location where to download the file.

March 25, 2012 at 5:37 PM

in the above example of uploading file if we save the file on server which is present in the saveFile instence then please tell me at which location file will be save . i am using Apache Tomacat7.0 Application Server and using the following code :

import java.io.*;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class FileUploadServlet extends HttpServlet {


protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
       String contentType = request.getContentType();
if ((contentType != null) && (contentType.indexOf("multipart/form-data") >= 0)) {
DataInputStream in = new DataInputStream(request.getInputStream());
int formDataLength = request.getContentLength();
byte dataBytes[] = new byte[formDataLength];
int byteRead = 0;
int totalBytesRead = 0;
while (totalBytesRead < formDataLength) {
byteRead = in.read(dataBytes, totalBytesRead,formDataLength);
totalBytesRead += byteRead;
}
String file = new String(dataBytes);
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;
pos = file.indexOf("filename=\"");

pos = file.indexOf("\n", pos) + 1;

pos = file.indexOf("\n", pos) + 1;
S
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;

FileOutputStream fileOut = new FileOutputStream(saveFile);
fileOut.write(dataBytes, startPos, (endPos - startPos));

fileOut.flush();
fileOut.close();
out.println("<html><body><b>You have successfully upload the file by the name of:</b>");
out.println(saveFile);
out.println("</body></html>");
 }
}
}

Upload and download file

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