Download file from MySql database

[puk284]

Hi,

I have written the following code to download a file from a MySql database using a Servlet.The problem i have is that i havnt done it right. Can someone please point me in the right direction. Any help will be greatly appreciated. Thank you for your help.

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.sql.Blob;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/
Servlet implementation class datadownload
/
public class datadownload extends HttpServlet {
private static final long serialVersionUID = 1L;

/
@see HttpServlet#HttpServlet()
/
public datadownload() {
super();
// TODO Auto-generated constructor stub
}

/
@see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub

}

/
@see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String connectionURL = "jdbc:mysql://localhost/filestore";
Connection con = null;
Statement stmt= null;
ResultSet res = null;
response.setContentType("application/octet-stream");

try{
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection(connectionURL, "root", "");
stmt=con.createStatement();
res =stmt.executeQuery("select * from save_file where id='15'");
if (res .next()) {
Blob File=res .getBlob("file");
InputStream x=File.getBinaryStream();
int size=x.available();
ServletOutputStream Fileout = response.getOutputStream();
FileInputStream f = new FileInputStream("");
int nextByte = f.read();

while ( nextByte != -1 ) {
out.write(nextByte);
nextByte = f.read();
}
out.flush();
}
}




catch(Exception e){
System.out.println("Exception :"+e);
}
finally{
try{
stmt.close();
con.close();
}
catch(Exception e){
System.out.println(e);
}
}
}
}

 

[Diancecht]

What error are you getting?

Cheers,
Dian

 

[prosper]

InputStream x=File.getBinaryStream();
int size=x.available();
ServletOutputStream Fileout = response.getOutputStream();
FileInputStream f = new FileInputStream("");
int nextByte = f.read();

while ( nextByte != -1 ) {
out.write(nextByte);
nextByte = f.read();
}

replaced by

FileInputStream x=File.getBinaryStream();
int size=x.available();
ServletOutputStream Fileout = response.getOutputStream();
int nextByte = x.read();
while ( nextByte != -1 ) {
out.write(nextByte);
nextByte = x.read();
}

InputStream is an abstract class.

 

[prosper]

My code may not work, you may try to look at the following link:

http://www.roseindia.net/jdbc/display-blob-example.shtml

 

[Diancecht]

One month later ...

Cheers,
Dian