/** -----------------------------------------------------------------
  *  Copyright 1922 Sun Microcomputers, Inc.,
  *  and Mark Andrews.  All rights reserved.
  * -----------------------------------------------------------------
  *
  *  FormDisplayServlet servlet
  * 
  *  This servlet reads items which the user has entered
  *  in the Guestbook, and responds appropriately -- with
  *  either a thank-you page or an "error-and-please-try-again"
  *  message. Then it adds the user's input to a database.
	*
  *  This servlet shows how to incorporate a guestbook page
  *  or a registration page into a Web site. 
  */

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.util.*;
import java.text.*;

/** -----------------------------------------------------------------
  *  The FormDisplayServlet() class.
  *
  *@ param req Instance of class HttpServletRequest.
  *@ param res Instance of class HttpServletResponse.
  *@ exception IOException When inputting form data or writing
  *  the form data back to the browser.
  */
//////////////////////////////////////////////////////////////
//
// This method displays the form and gets user input.
//
public class FormDisplayServlet extends HttpServlet
{
  int connections;  // Variable to track number of visitors..
 
  public final String BASENAME = "samples";
  public final int NR_OF_PARAMS = 17; // Doesn't include check boxes.
  public final int MAX_CLASS_SIZE = 200;
  String userName;
        
  // String resources
  public final String s1 = "Guestbook Response Page";
  public final String s2 = "Thanks for Signing Our Guestbook!";
  public final String s3 = "Thank you for signing our guestbook! If you have requested" + "<BR>";
	public final String s4 = "information about setting up an e-commerce site," + "<BR>";
	public final String s5 = "we'll be getting back to you right away!" + "<BR>";
	public final String s6 = "Error: Registration file not found in your webserver doc root!<BR>";
	public final String s7 = "Please copy guestbook.txt to your servlets directory!<BR>";
	public final String s8 = "It looks like some information is missing from your guestbook form.";
  public final String s9 = "Please go back and fill in the following items so we can continue:";
  public final String s10 = "Thank you for signing our guestbook! Everything you have" + "<BR>";
	public final String s11 = "shared with us will be kept strictly confidential." + "<BR>";
											
/** ----------------------------------------------------------------- 
  *@ The init() method.
  *@
  *@ Initializes the servlet when the servlet is first loaded.
*/
 //////////////////////////////////////////////////////////////
 //
 // Here's the init() method.
 //
 public void init(ServletConfig config)
               throws ServletException
  {
     super.init(config);
		 connections = 0;
  }
  
  //Process the HTTP Post request
  boolean error;
  String want_offers = "YES";
  String want_info = "YES";
  Enumeration params;
  String[] entries = {"", "", "", "", "", "", "", "", "", "",
  	"", "", "", "", "", "", ""};
  
  // This servlet keeps track of a lot of strings.
  // These are the names of variables.
  public final String[] parms = {"firstname",  // 0
	   "lastname",		// 1
     "age",				// 2
     "profession",	// 3
     "email",			// 4
     "homepage",		// 5
     "address1",		// 6
     "address2",		// 7
     "city",				// 8
     "state",			// 9
     "zipcode",		//10
     "country",		//11
     "areacode",		//12
     "phone",			//13
     "faxareacode",//14
     "faxnumber",	//15
     "comments",		//16
     "want_offers",//17
     "want_info"		//18
  };
  	
  // These are the same variables, expressed as
  // labels that are written in English and look nicer
  // on the page.
  public final String[] labels = {"First Name",  // 0
	   "Last Name",		// 1
     "Age",				// 2
     "Profession",	// 3
     "Email",			// 4
     "Home Page",		// 5
     "Address 1",		// 6
     "Address 2",		// 7
     "City",				// 8
     "State/Province",			// 9
     "Zip/Postal Code",		//10
     "Country",		//11
     "Area/Country Code",		//12
     "Phone",			//13
     "Fax Area Code",//14
     "Fax Number",	//15
     "Comments",		//16
     "Send Offers",//17
     "Send Info"		//18
 };
  	
 //////////////////////////////////////////////////////////////
 //
 // This is the all-important doPost() method.
 //
 public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

  	// This line tells the servlet where the database is.
  	String guestbook = request.getRealPath("guestbook.txt");

    //First name
    String firstname = "";
    try { firstname = request.getParameter("firstname"); } catch (Exception e) { e.printStackTrace(); }
    userName = firstname;
    //Last name
    String lastname = "";
    try { lastname = request.getParameter("lastname"); } catch (Exception e) { e.printStackTrace(); }
    //Age
    String age = "Select One";
    try { age = request.getParameter("age"); } catch (Exception e) { e.printStackTrace(); }
    //Profession
    String profession = "";
    try { profession = request.getParameter("profession"); } catch (Exception e) { e.printStackTrace(); }
    //Email Address
    String email = "";
    try { email = request.getParameter("email"); } catch (Exception e) { e.printStackTrace(); }
    //Home Page
    String homepage = "http://";
    try { homepage = request.getParameter("homepage"); } catch (Exception e) { e.printStackTrace(); }
    //Street Address
    String address1 = "";
    try { address1 = request.getParameter("address1"); } catch (Exception e) { e.printStackTrace(); }
    //Apt. No., etc.
    String address2 = "";
    try { address2 = request.getParameter("address2"); } catch (Exception e) { e.printStackTrace(); }
    //City
    String city = "";
    try { city = request.getParameter("city"); } catch (Exception e) { e.printStackTrace(); }
    //State/Province
    String state = "";
    try { state = request.getParameter("state"); } catch (Exception e) { e.printStackTrace(); }
    //Zip/Postal Code
    String zipcode = "";
    try { zipcode = request.getParameter("zipcode"); } catch (Exception e) { e.printStackTrace(); }
    //Country
    String country = "Select One";
    try { country = request.getParameter("country"); } catch (Exception e) { e.printStackTrace(); }
    //Area/Country Code
    String areacode = "";
    try { areacode = request.getParameter("areacode"); } catch (Exception e) { e.printStackTrace(); }
    //Phone Number
    String phone = "";
    try { phone = request.getParameter("phone"); } catch (Exception e) { e.printStackTrace(); }
    //Fax Area Code
    String faxareacode = "";
    try { faxareacode = request.getParameter("faxareacode"); } catch (Exception e) { e.printStackTrace(); }
    //Fax Number
    String faxnumber = "";
    try { faxnumber = request.getParameter("faxnumber"); } catch (Exception e) { e.printStackTrace(); }
    //Comments
    String comments = "";
    try { comments = request.getParameter("comments"); } catch (Exception e) { e.printStackTrace(); }
    response.setContentType("text/html");
    PrintWriter pw = new PrintWriter (response.getOutputStream());

    pw.println("<html>");
    pw.println("<head><title>GuestBookServlet</title></head>");
    pw.println("<body>");

    /*
    // These operations were in a JBuilder tutorial.
    // They worked well, and I might put them to
    // some use someday.
    //
    // pw.print("<P>You are visitor number ");
    // connections++;
    // pw.println(Integer.toString(connections));
    // pw.print(". <BR><BR>");
    // End tutorial print operations.
		*/
		
    // Find out if the user left any items blank.
    params = request.getParameterNames();

    String s;
    String b = "BLANK";
  	String dbString = "";
  	error = false;
  	
    // Check carefully to see if any items are blank.
    for (int n = 0; n < NR_OF_PARAMS; n++) {
      s = request.getParameter(parms[n]);
      if (s.length() == 0) {

         // Some fields aren't required, thus
         // can be left blank without generating errors.
         switch (n) {
            // These are the important ones.
           case 0:  // firstname
           case 1:  // lastname
           case 4:  // email
           case 8:  // city
           case 9:  // state
           case 10: // zipcode
           case 11: // country
           	 entries[n] = "ERROR";
         	   error = true;
          	 break;
       	 	 // These are optional.
       	 	 case 2:  // age
         	 case 3:  // profession
         	 case 5:  // homepage
         	 case 6:  // address1
         	 case 7:  // address2 
           case 12: // areacode
         	 case 13: // phone 
         	 case 14: // faxareacode 
         	 case 15: // faxnumber 
         	 case 16: // comments
         	 case 17: // want_offers
         	 case 18: // want_info
         		 entries[n] = "BLANK";
         }   
      }   
      
		  // This is the string that gets printed to the
		  // database. Items are separated by the "|" character.
      dbString = dbString + s + "|";
    }

    // Get the check-box parameters at the bottom of
    // the form.
    if (request.getParameter("want_offers") == null)
    	want_offers = "NO";
    if (request.getParameter("want_info") == null)
    	want_info = "NO";

		// This *ends* the string that gets printed to the
		// text file. It adds the checkbox responses
		// to the end of the input data.
    dbString = dbString + want_offers + "|";
    dbString = dbString + want_info;    
    
    // If any required field has been left blank, 
    // we display an error page.
    if (error == true) {
      params = request.getParameterNames();
   	  printErrorPage(pw, params, true);	
    }
    
    // If no important items have been left blank, 
    // we display the Thank You HTML page and update the 
    // database with the user's input.
    else {
		  // This is the method that prints the data to the database
		  // and displays the Thank You HTML page.
		  printData(null, null, dbString, guestbook, pw);
		}				

    pw.println("</body></html>");
    pw.close();
  }
  
 /** -------------------------------------------------------------
  * The printErrorPage() method.
  *
  * Opens registration location file and writes 
  * registration data to file
  *
  * @param pw PrintWriter.
  * @param Vector arg parameter Vector.
  * @boolean errorStatus.
  * @return Boolean indicating whether database entry was  
  * successful.
  * @exception IOException When opening, reading from, or
  * writing the output stream to the registration file.
  */
    
	//////////////////////////////////////////////////////////
	//
	// This method outputs error messages to the browser page.
	//
  public void printErrorPage(PrintWriter pw, Enumeration e,
            boolean errorStatus)   throws IOException
  {
    // This loop prints the error message.
    pw.print("<H1>Oops!</H1>");
 
    pw.print("<BR>");
    pw.print(s8 + "<BR>");
    pw.println(s9 + "<BR><P>");

    for (int n = 0; n < NR_OF_PARAMS; n++) {
    	if (entries[n] == "ERROR") {
    		pw.println(labels[n]);
        pw.print("<BR>");
        entries[n] = "";
   	  }	
    }
    
    pw.println("</BODY></HTML>");
    pw.flush();
    pw.close();
    return;
  } // end of printErrorPage()
  	
  /** -----------------------------------------------------------------
   * @ printData() method.
   * 
   * @ Displays a Thank You page and writes 
   *   data to the database.
	 * 
   * @param dt date -- not used in this implemementation.
   * @param loc  -- not used in this implemementation.
   * @param rData Data string.
   * @param aFile Data file name.
   * @return Boolean indicating whether data was  
   * successfully written.
   *
   * @exception IOException When opening, reading from, or
   *  writing the output stream to the database.
   */ 
  //////////////////////////////////////////////////////////
	//
	// Display a Thank You page and add 
  // the user's input to the database.
	//
  public synchronized boolean printData(String dt, String loc, 
          String rData, String aFile, PrintWriter pw) 
          	    throws IOException
  {
    boolean done = false;
    int numLns = 0;
    String line = null, regLine = null;
    String fileLine = null;
    String regFile = aFile;
    String regData = rData;
    BufferedReader readFile = null;
    Vector lines = new Vector();
           
    // Set up a buffer to read out items that are
    // already in the database.
    try
      {
 			// Heading for the Thank You page.
    	pw.print("<H2>Thanks for your feedback, " + userName + "!</H2>");

			pw.println(s10);
			pw.println(s11);
		  
	 		// This is a test.
 			// pw.println("RegData: " + regData + "<BR>");

      readFile = new BufferedReader(new FileReader(regFile));
      }
    catch(Exception e)
      {
        pw.println(s6);
        pw.println(s7);
        pw.println(e.toString());
        pw.flush();
        return done;
      }
   	//////////////////////////////////////////////////
    //
    // Copy all current lines in the database 
    // into a Vector. How inefficient! We need
    // an RDBMS.
    //
    while((regLine = readFile.readLine()) != null) {
    	lines.addElement((Object)regLine);
    }
    pw.flush();
    readFile.close();
 	
    // Check to see if we can write to the database.
		try {
		  pw = new PrintWriter(new FileWriter(regFile));
		} catch(Exception e) {
		  pw.println("Error: Could not write to file " + regFile);
		  pw.println(e.toString());
		  pw.flush();
		  return done;
		}
  	
  	//This loop adds the user's input to the database;
    if((numLns = lines.size()) > 0)
      {
        for(int i = 0;i < numLns;i++)
          {
             line = (String)lines.elementAt(i);
             pw.println(line); 
          }
          // This is the line that does the writing
          // to the database file.
          pw.println(regData);
          done = true;
        }
        pw.flush();
        pw.close();

    return done;

  } // end of printData()  	  	
        	 
} // end of class FormDisplayServlet