/* Survey.java
Processes the consumer electronics survey form, updating the
file that stores the survey data and producing the cumulative
number of votes in the survey. The survey data file, survdat.ser,
is stored on the Web server.
*/
import java.io.*;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class Survey extends HttpServlet {
protected void processRequest(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
int[] votes = null;
int index;
int vote;
File survdat = new File("c:/Users/bob7/My Documents/survdat.ser");
String gender;
String[] products = {"TV", "Digital Camera", "MP3 player",
"DVD player/recorder", "Camcorder", "PDA", "Other"};
// Set the content type for the response and get a writer
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
// Create the initial part of the response document
out.println("");
out.println("");
out.println("Return message");
out.println("");
out.println("");
// Synchronize a block for the votes file access
synchronized (this) {
// If the file already exists, read in its data
try {
if (survdat.exists()) {
ObjectInputStream indat = new
ObjectInputStream(new FileInputStream(
survdat));
votes = (int[]) indat.readObject();
indat.close();
}
// If the file does not exist (this is the first
// vote), create the votes array
else {
votes = new int[14];
}
} catch (Exception e) {
e.printStackTrace();
}
// Get the gender of the survey respondent’s
gender = request.getParameter("gender");
// Add the consumer electronics vote of the response
// to the votes array
vote = Integer.parseInt(request.getParameter ("vote"));
if (gender.equals("male")) {
vote += votes.length / 2;
}
votes[vote]++;
//Write updated votes array to disk
ObjectOutputStream outdat = new ObjectOutputStream(
new FileOutputStream(survdat));
outdat.writeObject(votes);
outdat.flush();
outdat.close();
} //** end of the synchronized block
// Create the initial response information
out.println(
" Thank you for participating in the");
out.println(" Consumer Electronics Survey
");
out.println(" Current Survey Results:
");
// Create the cumulative total votes return information
// for females
out.println(" For Female Respondents
");
for (index = 0; index < votes.length / 2; index++) {
out.print(products[index]);
out.print(": ");
out.println(votes[index]);
out.println("
");
}
// Create the cumulative total votes return information
// for males
out.println(" For Male Respondents
");
for (index = votes.length / 2; index < votes.length;
index++) {
out.print(products[index - (votes.length / 2)]);
out.print(": ");
out.println(votes[index]);
out.println("
");
}
out.close();
}
protected void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
protected void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
}