Creating Directories using Servlet outside the web app

[J Das]

hello to all , please help me in creating directories using servlet outside the web app . creating directories inside the web app is not a good idea as recommended by many . whenever the application is clean and build again , the directories and files inside it gets deleted (which is not safe) . So i would like to know how can we do it outside the application. I have done it inside the web application for which the code is shown below. The code below is a servlet which gets executed when a link is clicked ( this link is a user account confirmation link ) . when the user clicks the link , the below servlet runs , and when this servlet runs the account of that user is activated. A folder gets created for every user on successful activation of their accounts .

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package mypack;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 *
 * @author JD
 */
public class linkServlet extends HttpServlet {

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        RequestDispatcher rd = null;
        HttpSession sess = request.getSession();
        String uemail = (String) sess.getAttribute("thisuser");

        //String uemail = request.getParameter("user");
        System.out.println("the user is" + uemail);
        //boolean userExits=false;
        //boolean acActivated=false;

        if (uemail != null) {

            mypack.DBHandler d = new mypack.DBHandler();
            int r = d.updateAC(uemail);

            if (r == 1) {


                /*String strProjectDir = request.getRealPath("WEB-INF/");
                File ProjectDir = new File(strProjectDir);
                if (!ProjectDir.exists()) {
                ProjectDir.mkdir();
                }*/
                String jd = this.getServletContext().getRealPath(uemail);
                File directory = new File(jd);
                directory.mkdir();
                rd = request.getRequestDispatcher("good.jsp");


            } else {
                rd = request.getRequestDispatcher("bad.jsp");

            }
            rd.forward(request, response);
        }

    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /** 
     * Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /** 
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>
}

This particular code ....

String jd = this.getServletContext().getRealPath(uemail);
                File directory = new File(jd);
                directory.mkdir();

creates a directory inside the web app with the username as the directory name.. I want to do this , but somewhere outside the web app. Please show me what should i do .

[Nam Ha Minh]

J Das wrote:
creates a directory inside the web app with the username as the directory name.. I want to do this , but somewhere outside the web app. Please show me what should i do .

Do you have trouble with using absolute path? Why don't you use absolute path, for example C:\userdir, D:\userdir...

[Abhay Agarwal]

I guess using Absolute path should work for you to save/create new directory outside web application.

If you have migrate your application to different machines/enivornments (either Windows or Linux) , then I would suggest you hard code the absolute path as key value pair in some properties file in your web application.
for eg -

users.directory.home.directorypath =C://UserHomeDirectory

Then read this key value runtime in your Servlet and append username to this path. So if username is 'testUser' then full path becomes C://UserHomeDirectory/testUser. Now use your directory creation code to create new directory.

~ abhay

[J Das]

Do you have trouble with using absolute path? Why don't you use absolute path, for example C:\userdir, D:\userdir...

I did this ..it is working fine ? but i want to know is there any proper alternative solutions ?

                String jd = "D:/".concat(uemail);
                File directory = new File(jd);
                directory.mkdir();
                

and after creating this directory , i need to upload files to this directory .. For every user registration, a directory will be created , and when the user logs in , that user can upload files to his directory . The code for uploading to respective directory is shown below :

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package mypack;

import java.io.DataInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 *
 * @author JD
 */
public class uploadfile extends HttpServlet {

    /** 
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        int r = 0;
        HttpSession session = request.getSession();
        String user = session.getAttribute("username").toString();
        HttpSession sess = request.getSession();
        String uemail = (String) sess.getAttribute("thisuser");

        //to get the content type information from JSP Request Header
        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);

            // out.println(file);

            String saveFile = file.substring(file.indexOf("filename=\"") + 10);
            saveFile = saveFile.substring(0, saveFile.indexOf("\n"));
            saveFile = saveFile.substring(saveFile.lastIndexOf("\\") + 1, saveFile.indexOf("\""));
            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;

            String rootPath = "D:/".concat(uemail);
            File myFile = new File(saveFile);
            FileOutputStream myFileOut = new FileOutputStream(myFile);
            System.out.println("the path is" + myFile.getAbsolutePath());
            FileOutputStream fileOut = new FileOutputStream(rootPath + "/" + saveFile);

            DBHandler d = new DBHandler();
            d.insertfile(saveFile, rootPath.concat("\\").concat(saveFile));
            fileOut.write(dataBytes, startPos, (endPos - startPos));
            fileOut.flush();
            fileOut.close();

            RequestDispatcher rd = request.getRequestDispatcher("index.jsp");
            rd.forward(request, response);

        }
    }
    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">

    /**
     * Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException,
            IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException,
            IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>
}

[Nam Ha Minh]

J Das wrote:


I did this ..it is working fine ? but i want to know is there any proper alternative solutions ?

It should work fine, as long as you have total control of the server.