1. Template + Hamlet = Page
2. Template
<HTML>
<HEAD>
<TITLE>Guestbook</TITLE>
<LINK REL="stylesheet" TYPE="text/css" HREF="GuestBook.css" MEDIA="all" />
</HEAD>
<BODY>
<FORM ACTION="GuestBook.html" METHOD="POST">
<DIV CLASS="Title">Guestbook</DIV>
<DIV CLASS="Text">Add your comment here:</DIV>
<DIV CLASS="Text"><TEXTAREA CLASS="entryfield" NAME="Comment"></TEXTAREA></DIV>
<DIV CLASS="Text"><INPUT CLASS="button" TYPE="SUBMIT" VALUE="Add" /></DIV>
</FORM>
<DIV CLASS="Text">
<REPEAT ID="Comments">
<DIV CLASS="Text">Date: <REPLACE ID="Date">26.9.2007</REPLACE></DIV>
<DIV CLASS="Text"><REPLACE ID="Comment">Hello world!</REPLACE></DIV>
<BR/>
</REPEAT>
</DIV>
<HR CLASS="Separator" />
<INCLUDE SRC="Copyright.html"/>
</BODY>
</HTML>
3. Hamlet
/**
*
* © Copyright International Business Machines Corporation 2007, 2009.
* All rights reserved.
*
* The 'GuestBook' hamlet implements a simple guest book.
*
* File : GuestBook.java
* Created : 2007/08/27
*
* @author Rene Pawlitzek
* @version 1.00, 2009/02/13
* @since JDK 1.5
*
* History : 2007/08/27, rpa, new file
* 2009/02/13, rpa, code review
*
*/
package com.ibm.webui;
import java.io.*;
import java.util.*;
import java.text.*;
import javax.servlet.*;
import javax.servlet.http.*;
import com.ibm.hamlet.*;
import org.apache.commons.lang.*;
import org.apache.log4j.*;
import org.xml.sax.*;
public class GuestBook extends Hamlet {
private static final long serialVersionUID = 5264892082158101750L;
private static final String fileName = "Comments.dat";
private static Logger logger = Logger.getLogger (GuestBook.class.getName ());
private static String filePath;
private static Vector<Comment> comments;
// data structure to store comments
private static class Comment implements Serializable {
private static final long serialVersionUID = -1199467372679306131L;
public Date date;
public String text;
public Comment (Date date, String text) {
this.date = date;
this.text = text;
} // Comment
} // Comment
// handler to provide the dynamic content
protected class GuestBookHandler extends ExHamletHandler { // ExHamletHandler is new in Hamlets v1.7
private int i = 0;
private Comment curComment;
private Vector<Comment> comments;
private SimpleDateFormat format;
public GuestBookHandler (Hamlet hamlet, Vector<Comment> comments) {
super (hamlet);
this.comments = comments;
format = new SimpleDateFormat ("yyyy-MM-dd HH:mm:ss");
} // GuestBookHandler
public int getCommentsRepeatCount (String id, String name, Attributes atts) {
return comments.size ();
} // getCommentsRepeatCount
public String getDateReplacement (String id, String name, Attributes atts) {
curComment = (Comment) comments.elementAt (i);
return format.format (curComment.date);
} // getDateReplacement
public String getCommentReplacement (String id, String name, Attributes atts) {
i++;
return curComment.text;
} // getCommentReplacement
} // GuestBookHandler
// initialization
@SuppressWarnings("unchecked")
public void init () {
BasicConfigurator.configure ();
logger.debug ("init");
filePath = getServletContext ().getRealPath ("/");
logger.debug (filePath);
try {
ObjectInputStream in =
new ObjectInputStream (new FileInputStream (filePath + fileName));
comments = (Vector<Comment>) in.readObject ();
} catch (Exception e) {
comments = new Vector<Comment> ();
} // try
} // init
// input processing
public void doPost (HttpServletRequest req, HttpServletResponse res) throws ServletException {
try {
logger.debug ("doPost");
String text = req.getParameter ("Comment");
if (text != null) {
text = StringEscapeUtils.escapeHtml (text);
Comment comment = new Comment (new Date (), text);
comments.add (0, comment);
ObjectOutputStream out =
new ObjectOutputStream (new FileOutputStream (filePath + fileName));
out.writeObject (comments);
} // if
doGet (req, res);
} catch (Exception e) {
logger.error ("", e);
} // try
} // doPost
// output processing
public void doGet (HttpServletRequest req, HttpServletResponse res) throws ServletException {
try {
logger.debug ("doGet");
ExHamletHandler handler = new GuestBookHandler (this, comments);
serveDoc (req, res, "GuestBookTemplate.html", handler);
} catch (Exception e) {
logger.error ("", e);
} // try
} // doGet
} // Guestbook
/* ----- End of File ----- */
4. Page
