package eu.dnetlib.server;

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

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


public class DownloadFile extends HttpServlet {
	private static final long serialVersionUID = 1L;

    public DownloadFile() {
        super();
    }

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		 String filePath = request.getParameter("filename");
	        File downloadFile = new File(filePath);
	        FileInputStream inStream = new FileInputStream(downloadFile);
	         
	        // if you want to use a relative path to context root:
	        String relativePath = getServletContext().getRealPath("");
	  
	         
	        // obtains ServletContext
	        ServletContext context = getServletContext();
	         
	        // gets MIME type of the file
	        String mimeType = context.getMimeType(filePath);
	        if (mimeType == null) {        
	            // set to binary type if MIME mapping not found
	            mimeType = "application/octet-stream";
	        }

	         
	        // modifies response
	        response.setContentType(mimeType);
	        response.setContentLength((int) downloadFile.length());
	         
	        // forces download
	        String headerKey = "Content-Disposition";
	        String headerValue = String.format("attachment; filename=\"%s\"", downloadFile.getName());
	        response.setHeader(headerKey, headerValue);
	         
	        // obtains response's output stream
	        OutputStream outStream = response.getOutputStream();
	         
	        byte[] buffer = new byte[4096];
	        int bytesRead = -1;
	         
	        while ((bytesRead = inStream.read(buffer)) != -1) {
	            outStream.write(buffer, 0, bytesRead);
	        }
	         
	        inStream.close();
	        outStream.close();    
	        downloadFile.delete();

		
	}


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

	}

}