Print to txt file from servlet and jsp's
Question
I can't seem to get my web application to write to my WEB-INF/EmailList.txt My code is this
Servlet:
package email;
import business.User;
import data.UserIO;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
*
* @author Richard Davy
*/
@WebServlet(name = "AddToEmailServlet", urlPatterns = {"/AddToEmailServlet"})
public class AddToEmailServlet 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");
try (PrintWriter out = response.getWriter()) {
/* TODO output your page here. You may use following sample code. */
out.println("<!DOCTYPE html>");
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet AddToEmailServlet</title>");
out.println("</head>");
out.println("<body>");
out.println("<h1>Servlet AddToEmailServlet at " + request.getContextPath() + "</h1>");
out.println("</body>");
out.println("</html>");
}
}
// <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
/**
* 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 {
//get parameters from the form
String firstName = request.getParameter("firstName");
String lastName = request.getParameter("lastName");
String email = request.getParameter("email");
//get relative file name
ServletContext context = getServletContext();
String path = context.getRealPath("/WEB-INF/EmailList.txt");
//add info to text file
User user = new User(firstName, lastName, email);
UserIO.add(user, path);
//send response to browser
response.setContentType("text/html;charset=utf-8");
PrintWriter out = response.getWriter();
out.println(
"<!Doctype html public \"-//W3C//DTD HTML 4.0 Transitional//EN\">\n"
+ "<html>\n"
+ "<head>\n"
+ " <title>Thank you for Joining</title>\n"
+ "</head>\n"
+ "<body>\n"
+ "<h1>Thanks for joining our email list</h1>\n"
+ " <p>Here is the information you gave:</p>"
+ " <table cellspacing=\"5\" cellpadding=\"5\" border=\"1\">\n"
+ " <tr>\n"
+ " <td>First Name: </td>\n"
+ " <td>" + firstName + "</td>\n"
+ " </tr>\n"
+ " <tr>\n"
+ " <td>last Name: </td>\n"
+ " <td>" + lastName + "</td>\n"
+ " </tr>\n"
+ " <tr>\n"
+ " <td>Email: </td>\n"
+ " <td>" + email + "</td>\n"
+ " </tr>"
+ " </table>\n"
+ " <p>If you wish to add another email address click the return<br/>\n"
+ " button below. </p>"
+ " <form action=\"join_email_list.html\">\n"
+ " <input type=\"submit\" value=\"return\">\n"
+ " </form>"
+ " </body>\n"
+ " </html>\n"
);
out.flush();
out.close();
}
/**
* 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 {
doPost(request, response);
}
/**
* Returns a short description of the servlet.
*
* @return a String containing servlet description
*/
@Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}
UserIO class:
package data;
import business.User;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
/**
*
* @author Richard Davy
*/
public class UserIO {
public static void add(User user, String filepath) throws IOException{
FileOutputStream file = new FileOutputStream(filepath, true);
String firstName = user.getFirstName();
String lastName = user.getLastName();
String email = user.getEmail();
PrintWriter writer = new PrintWriter(file);
writer.println(user.getEmail() + "|" + user.getFirstName() + "|" + user.getLastName());
//System.out.print(email + "|" + firstName + "|"
// + lastName);
}
}
I have gotten the real path as I was supposed to, but it isn't working any idea what is going on here I have tried it every way that I could and I can't seem to figure out what is going on, I am using Netbeans 8 and Tomcat 8 on a windows 7 machine. Is there something that may need to be reconfigured that I am overlooking.
3 answers
solution1
0 2014-06-11 05:36:53
Change the add method in UserIO class as below :
public static void add(User user, String filepath) throws IOException {
BufferedWriter buffer;
buffer = new BufferedWriter(new FileWriter(filepath, true));
buffer.write(user.getEmail() + "|" + user.getFirstName() + "|"
+ user.getLastName());
buffer.newLine();
buffer.close();
}
solution2
0 2014-06-11 05:52:10
Have you tried by closing the PrintWriter in UserIO ?
if(writer!=null)
{
writer.close();
}
solution3
0 2014-06-11 06:44:41
I suggest you one thing that is more easy to use rather than writing HTML content directly in Servlet.
Simply move the HTML content in a separate HTML/JSP file and forward the request to that HTML/JSP that will separate the view from Servlet.
Step to follow:
- Get the parameters from the request that is submitted by form
- Set the parameters in the request attributes
- Use
${}pattern that will be replaced from the request attributes
Sample code:
thanksTemplate.jsp:
<!Doctype html public "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title>Thank you for Joining</title>
</head>
<body>
<h1>Thanks for joining our email list</h1>
<p>Here is the information you gave:</p>
<table cellspacing="5" cellpadding="5" border="1">
<tr>
<td>First Name:</td>
<td>${firstName}</td>
</tr>
<tr>
<td>last Name:</td>
<td>${lastName}</td>
</tr>
<tr>
<td>Email:</td>
<td>${email}</td>
</tr>
</table>
<p>
If you wish to add another email address click the return<br />
button below.
</p>
<form action="join_email_list.html">
<input type="submit" value="return">
</form>
</body>
</html>
AddToEmailServlet.java
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
// get parameters from the form
String firstName = request.getParameter("firstName");
String lastName = request.getParameter("lastName");
String email = request.getParameter("email");
...
request.setAttribute("firstName", firstName);
request.setAttribute("lastName", lastName);
request.setAttribute("email", email);
request.getRequestDispatcher("/WEB-INF/thanksTemplate.jsp").forward(request, response);
}
Project structure:
webapp
|
|___WEB-INF
|
|__thanksTemplate.jsp
|__web.xml
Read more about
Note: Don't forget to close the stream. Always handler it in try-catch-finally or as you are already using The try-with-resources Statement .
If you are using Eclipse IDE then you might looking at wrong location. The resultant file will be under tomcat tmp directory as shown below:
Simply print the resultant path and look at this location.
.metadata\.plugins\org.eclipse.wst.server.core\tmp0\wtpwebapps\MyWebProject\WEB-INF\EmailList.txt
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