File Upload and Download: March 2010

Today I am going to describe how to insert the uploaded file in to Mysql database.For this we need apache fileupload jar files commons-fileupload-1.2.1.jar and commons.io-1.4.jar. . You can download the latest version of the package from http://commons.apache.org/downloads/download_fileupload.cgi.
Now first I am writing a class file

FileUploadListner.java

package servlet;

import org.apache.commons.fileupload.ProgressListener;

public class FileUploadListener implements ProgressListener
{
    private volatile long
      bytesRead = 0L,
      contentLength = 0L,
      item = 0L;

    public FileUploadListener()
    {
      super();
    }

    public void update(long aBytesRead, long aContentLength, int anItem)
    {
        bytesRead = aBytesRead;
        contentLength = aContentLength;
        item = anItem;
    }

    public long getBytesRead()
    {
        return bytesRead;
    }

    public long getContentLength()
    {
        return contentLength;
    }

    public long getItem()
    {
        return item;
    }
}

Now I am writing a servlet which will insert the file into database.

MyUploadServlet.java

package servlet;
import DBConnection;
import javax.servlet.http.HttpServlet;
import javax.servlet.Servlet;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Iterator;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.fileupload.FileUploadException;
import org.apache.commons.fileupload.disk.DiskFileItemFactory;
import org.apache.commons.fileupload.servlet.ServletFileUpload;
import java.sql.*;
public class MyUploadServlet extends HttpServlet implements Servlet
{
    private String filename;
    public MyUploadServlet()
    {
        super();
    }
protected void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException
    {
doPost(request,response);
    }
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException
    {
        DBConnection con=new DBConnection();
    PrintWriter ptr=response.getWriter();
    String jnan="";
// create file upload factory and upload servlet
        FileItemFactory factory = new DiskFileItemFactory();
        ServletFileUpload upload = new ServletFileUpload(factory);
        // set file upload progress listener
        FileUploadListener listener = new FileUploadListener();
        HttpSession session = request.getSession();
        session.setAttribute("LISTENER", listener);
        // upload servlet allows to set upload listener
        upload.setProgressListener(listener);
        List uploadedItems = null;
        FileItem fileItem = null;
         try
        {
            // iterate over all uploaded files
            uploadedItems = upload.parseRequest(request);
            Iterator i = uploadedItems.iterator();
            String str1[]={"","","","","","","","","","","","",""};
            int cc=0;
            while (i.hasNext())
            {
                fileItem = (FileItem) i.next();
                if(fileItem.isFormField() == true&&cc!=2)
                {
                jnan=String.valueOf(fileItem);
                jnan=jnan.substring(jnan.indexOf("FieldName=")+10,jnan.length());
                str1[cc]=jnan;
                cc++;
            }

        if (fileItem.isFormField() == false)
{
            if (fileItem.getSize() > 0)
            {
                File uploadedFile = null;
                String myFullFileName = fileItem.getName(),
                myFileName = "",
                slashType = (myFullFileName.lastIndexOf("\\") > 0) ? "\\" : "/"; // Windows or UNIX
                int startIndex = myFullFileName.lastIndexOf(slashType);
//Get File Name
myFileName = myFullFileName.substring(startIndex + 1, myFullFileName.length());
//Get File Extension
                String fileExt=myFileName.substring(myFileName.indexOf("."),myFileName.length());
// Create new File object

try{
ByteArrayInputStream bs=new ByteArrayInputStream(fileItem.get());
String query="INSERT INTO image(img) VALUES(?)";
PreparedStatement pst=con.conn.prepareStatement(query);
pst.setBinaryStream(1, bs,(int)fileItem.getSize());
pst.execute();
}
catch(Exception e)
{
System.out.println("in MyUploadServlet..Error:- "+e.getMessage());
}
}

                }

            }
        }
        catch (FileUploadException e)
        {
            System.out.println("in MyUploadServlet..Error:- "+e.getMessage());
        }
        catch (Exception e)
        {
            System.out.println("in MyUploadServlet..Error:- "+e.getMessage());
        }
        finally
        {
            con.DisconnectCon();
        }
    }
}

Here DBConnection is a class file.I am using this class to connect to mysql database from my eclipse.I made a connection pooling from apache tomcat 5.5 to Mysql.This class file is given below.
DBConnection.java:-

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;

public class DBConnection {

    private javax.naming.Context ic;
    private javax.sql.DataSource ds;
    public java.sql.Connection conn;

    public DBConnection()
    {
        try
        {

            ic=(Context)new InitialContext().lookup("java:comp/env");
            ds=(DataSource)ic.lookup("jdbc/MyJndiName");
            conn=ds.getConnection();
        }
        catch(Exception e)
        {
            System.out.println("Error in DBConnection "+e.getMessage());
        }
    }
    public void DisconnectCon()
    {
        try
        {
            conn.close();
        }
        catch(Exception e)
        {
            System.out.println("Error in DisconnectCon "+e.getMessage());
        }
    }
}