How to Download file from server in Java

This is example using servlet, you must be basic knowledge of file handling, because here we have to create file into specifric folder.




import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/DownLoadFile")
public class DownLoadFile extends HttpServlet {
private static final long serialVersionUID = 1L;

public DownLoadFile() {
super();

}

protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {

response.setContentType("text/html");
PrintWriter out = response.getWriter();

            //create file name
String filename = "customer.csv";
                 //create folder
String upload = "/folderCsv/";
             //method for getting path 
String filepath = request.getServletContext().getRealPath(upload);

// creates the save directory if it does not exists
File folder = new File(filepath);
if (!folder.exists()) {

folder.mkdir();
}

response.setContentType("APPLICATION/OCTET-STREAM");
response.setHeader("Content-Disposition", "attachment; filename=\""
+ filename + "\"");

FileInputStream fileInputStream = new FileInputStream(filepath
+ File.separator + filename);

int i;
while ((i = fileInputStream.read()) != -1) {
out.write(i);
}
fileInputStream.close();
out.close();

}

now jsp contents are in my coding

 <a href="DownloadExportFile" target="_blank"> <img src="img/excellogo.png" height="200px" width="200px"></a></center>
                        </div><br>

here i have use a image for downloading


Thanks
Keep Happy Learning