Hai,I need to download the data file from database with csv format using java/servlet.I would like to download the csv file when user clicks download button.
Thanks in Advance
Here is an application that upload and save the file into database and allow the user to download that 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 saveFile=""; 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); 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/test"; 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();} } %> <form method="post" action="../DownloadServlet"> <input type="hidden" name="f" value=<%=saveFile%> <input type="submit" value="Download"> </form>
continue..
3)DownloadServlet.java:
import java.io.*; import java.net.* import javax.servlet.*; import javax.servlet.http.*; public class DownloadServlet extends HttpServlet{ public void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException { response.setContentType("text/html"); PrintWriter out = response.getWriter(); String file=request.getParameter("f"); File f = new File (file); String filename=f.getName(); String type=getMimeType("file:"+file); response.setContentType (type); response.setHeader ("Content-Disposition", "attachment; filename=\""+filename+"\""); String name = f.getName().substring(f.getName().lastIndexOf("/") + 1,f.getName().length()); InputStream in = new FileInputStream(f); ServletOutputStream outs = response.getOutputStream(); int bit = 256; int i = 0; try { while ((bit) >= 0) { bit = in.read(); outs.write(bit); } } catch (IOException ioe) { ioe.printStackTrace(System.out); } outs.flush(); outs.close(); in.close(); } public static String getMimeType(String fileUrl) throws java.io.IOException, MalformedURLException { String type = null; URL u = new URL(fileUrl); URLConnection uc = null; uc = u.openConnection(); type = uc.getContentType(); return type; } }
Ads