Tuesday, December 30, 2008

JavaDay 2009 a Roma

Il giorno 24 Gennaio 2009 parteciperò al JavaDay 2009 a Roma.

Se ti interessa fare due chiacchiere a proposito dei prossimi sviluppi di Parancoe, Scarabocio o JSlideShare, contattami durante la mia presentazione sull'uso dei controller annotati in Spring 2.5, o mandami una mail.


Javaday Roma III Edizione


Se vi interessa fare il viaggio insieme o cenare assieme la sera antecedente al JavaDay, trovate le informazioni qui: http://javadayroma.wikispaces.com/Treno

Thursday, December 11, 2008

Using Tiles 2 in a Prancoe project

First of all add the Tiles dependency to your pom.xml:


<dependency>
<groupId>org.apache.tiles</groupId>
<artifactId>tiles-core</artifactId>
<version>2.1.0</version>
</dependency>
<dependency>
<groupId>org.apache.tiles</groupId>
<artifactId>tiles-jsp</artifactId>
<version>2.1.0</version>
</dependency>


Specify the places of the Tiles configurations and the Tiles view resolver in your parancoe-servlet.xml file:


<bean id="tilesConfigurer"
class="org.springframework.web.servlet.view.tiles2.TilesConfigurer">
<property name="definitions">
<list>
<value>/WEB-INF/tiles/defs/default.xml</value>
</list>
</property>
</bean>

<bean id="viewResolver"
class="org.springframework.web.servlet.view.UrlBasedViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.tiles2.TilesView"/>
<!-- Default values for prefix and suffix
<property name="prefix" value="/WEB-INF/jsp/"/>
<property name="suffix" value=".jsp"/>
-->
</bean>


Add the /WEB-INF/tiles/defs/default.xml file with the definitions of your views:


<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE tiles-definitions PUBLIC
"-//Apache Software Foundation//DTD Tiles Configuration 2.0//EN"
"http://tiles.apache.org/dtds/tiles-config_2_0.dtd">
<tiles-definitions>

<definition name="template.main" template="/WEB-INF/tiles/templates/main.jsp">
<put-attribute name="header" value="/WEB-INF/jsp/header.jsp"/>
<put-attribute name="menu" value="/WEB-INF/jsp/menu.jsp"/>
<put-attribute name="footer" value="/WEB-INF/jsp/footer.jsp"/>
</definition>

<definition name="login" extends="template.main">
<put-attribute name="main" value="/WEB-INF/jsp/login.jsp"/>
</definition>

<definition name="admin/conf" extends="template.main">
<put-attribute name="main" value="/WEB-INF/jsp/admin/conf.jsp"/>
</definition>

<definition name="admin/index" extends="template.main">
<put-attribute name="main" value="/WEB-INF/jsp/admin/index.jsp"/>
</definition>

<definition name="admin/logs" extends="template.main">
<put-attribute name="main" value="/WEB-INF/jsp/admin/logs.jsp"/>
</definition>

<definition name="admin/spring" extends="template.main">
<put-attribute name="main" value="/WEB-INF/jsp/admin/spring.jsp"/>
</definition>

<definition name="admin/users/list" extends="template.main">
<put-attribute name="main" value="/WEB-INF/jsp/admin/users/list.jsp"/>
</definition>

<definition name="admin/users/edit" extends="template.main">
<put-attribute name="main" value="/WEB-INF/jsp/admin/users/edit.jsp"/>
</definition>

<definition name="message" extends="template.main">
<put-attribute name="main" value="/WEB-INF/jsp/message.jsp"/>
</definition>

<definition name="genericError" extends="template.main">
<put-attribute name="main" value="/WEB-INF/jsp/genericError.jsp"/>
</definition>

<definition name="accessDenied" extends="template.main">
<put-attribute name="main" value="/WEB-INF/jsp/accessDenied.jsp"/>
</definition>

<definition name="welcome" extends="template.main">
<put-attribute name="main" value="/WEB-INF/jsp/welcome.jsp"/>
</definition>

<definition name="404" extends="template.main">
<put-attribute name="main" value="/WEB-INF/jsp/404.jsp"/>
</definition>

<definition name="500" extends="template.main">
<put-attribute name="main" value="/WEB-INF/jsp/500.jsp"/>
</definition>

</tiles-definitions>


Add the template in /WEB-INF/tiles/templates/main.jsp:


<%@ taglib uri="http://tiles.apache.org/tags-tiles" prefix="tiles" %>
<%@ include file="/WEB-INF/jsp/common.jspf" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<%@ include file="/WEB-INF/jsp/head.jspf" %>
</head>
<body>
<div id="nonFooter">
<tiles:insertAttribute name="header"/>
<div id="content">
<div id="content_main">
<tiles:insertAttribute name="main"/>
</div>
<tiles:insertAttribute name="menu"/>
</div>
</div>
<tiles:insertAttribute name="footer"/>
</body>
</html>


Now You can simplify your JSP pages, removing from them all the layout-related parts. For example the welcome page (/WEB-INF/jsp/welcome.jsp) was:


<%@ include file="common.jspf" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<%@ include file="head.jspf" %>
</head>
<body>
<div id="nonFooter">
<jsp:include page="header.jsp"/>
<div id="content">
<div id="content_main">
<c:choose>
<c:when test="${requestScope.lang eq 'it'}">
Questa è l'applicazione template per il framework
<a href="http://wwww.parancoe.org">Parancoe</a>.<br />
<br />
Da questo punto di partenza puoi iniziare a costruire la
tua nuova applicazione, sfruttando tutti i benefici che
derivano dall'uso di Parancoe.<br />
<br />
Per maggiori informazioni visita il sito di Parancoe:<br />
<br />
<a href="http://wwww.parancoe.org">http://wwww.parancoe.org</a>.<br />
</c:when>
<c:otherwise>
This is the template application of the
<a href="http://wwww.parancoe.org">Parancoe</a> framework.<br />
<br />
From this starting point you can build your own application,
with all benefits of the using of the Parancoe Framework.<br />
<br />
For more infos, visit the Parancoe framework Web site:<br />
<br />
<a href="http://wwww.parancoe.org">http://wwww.parancoe.org</a>.<br />
</c:otherwise>
</c:choose>
</div>
<jsp:include page="menu.jsp"/>
</div>
</div>
<jsp:include page="footer.jsp"/>
</body>
</html>


Now it's just:


<%@ include file="/WEB-INF/jsp/common.jspf" %>
<c:choose>
<c:when test="${requestScope.lang eq 'it'}">
Questa è l'applicazione template per il framework
<a href="http://wwww.parancoe.org">Parancoe</a>.<br />
<br />
Da questo punto di partenza puoi iniziare a costruire la
tua nuova applicazione, sfruttando tutti i benefici che
derivano dall'uso di Parancoe.<br />
<br />
Per maggiori informazioni visita il sito di Parancoe:<br />
<br />
<a href="http://wwww.parancoe.org">http://wwww.parancoe.org</a>.<br />
</c:when>
<c:otherwise>
This is the template application of the
<a href="http://wwww.parancoe.org">Parancoe</a> framework.<br />
<br />
From this starting point you can build your own application,
with all benefits of the using of the Parancoe Framework.<br />
<br />
For more infos, visit the Parancoe framework Web site:<br />
<br />
<a href="http://wwww.parancoe.org">http://wwww.parancoe.org</a>.<br />
</c:otherwise>
</c:choose>

Thursday, November 13, 2008

Building an AJAX chat with Parancoe and DWR

The AJAX integration through DWR 3 is not the main feature in Parancoe, but it's easy and funny. Let's see how simple is building a Web chat.

Starting from a project generated with Maven using the Parancoe Web Archetype, you need to add the Parancoe DWR Plugin to the dependencies in your pom.xml:


<dependency>
<groupId>org.parancoe</groupId>
<artifactId>parancoe-plugin-dwr</artifactId>
<version>2.0.2</version>
</dependency>


Then add the /dwr/* pattern to the mapping of the parancoe servlet in your web.xml.

Now DWR is ready to be used in your application. You check it building and deploying your application, and pointing your browser to <your_base_address>/dwr/index.html. You should see the DWR Test Page.

Then add a class with methods (a single method in this example) that will be invoked through AJAX:


package com.mycompany.testapp.ajax;

import org.directwebremoting.Browser;
import org.directwebremoting.annotations.RemoteMethod;
import org.directwebremoting.annotations.RemoteProxy;
import org.directwebremoting.ui.dwr.Util;
import org.springframework.stereotype.Component;

@Component
@RemoteProxy(name = "chat")
public class Chat {

@RemoteMethod
public void send(final String nickname, final String message) {
Browser.withCurrentPage(new Runnable() {
public void run() {
Util.addRows("chatLog", new String[][]{{nickname, message}});
}
});
}
}


Simple, isn't it? ...but powerful. When invoked that method will add a row to the table with id chatLog, in all browsers that are visualizing that page.

Let's see the page chat.jsp in which that method is invoked:


<%@ include file="WEB-INF/jsp/common.jspf" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html>
<head>
<%@ include file="WEB-INF/jsp/head.jspf" %>
<script src="${cp}/dwr/interface/chat.js" type="text/javascript"/>
<script src="${cp}/dwr/engine.js" type="text/javascript" />
<script src="${cp}/dwr/util.js" type="text/javascript" />
<title>Parancoe DWR chat</title>
</head>
<body>
<h1>DWR Chat</h1>

<table id="chatLog">
<thead>
<tr><th>Nickname</th><th>Message</th></tr>
</thead>
<tbody> </tbody>
</table>

<form id="chatForm" method="post" action="/sendMessage">
Nickname: <input id="nickname" type="text" /><br/>
Say: <input id="say" type="text" /><br/>
<input type="submit">
</form>

<script type="text/javascript">
function bindUI() {
$('chatForm').observe('submit', chatSubmit);
}

function chatSubmit(event) {
event.stop();
chat.send($F('nickname'), $F('say'));
}

dwr.engine.setActiveReverseAjax(true);
document.observe('dom:loaded', bindUI);
</script>
</body>
</html>


In your parancoe-servlet.xml file add the following configuration for enabling the active reverse AJAX in DWR:






Build and deploy your application. Open multiple windows of your browser(s) to <your_base_address>/chat.jsp, and start chatting:



Have fun with Parancoe!

Saturday, November 8, 2008

Parancoe 2.0

Last week the Parancoe Team (me and other smart people :) ) released the version 2.0 of the Parancoe meta-framework. With this release Parancoe achieved a great level of maturity.

In the next weeks, starting with this post, I will demonstrate how easy and pleasant is to develop applications with Parancoe.

First demonstration! :) How difficult is to start a new project with Parancoe? No difficult at all. Install Maven and type the following command:

mvn archetype:create -DarchetypeGroupId=org.parancoe \
-DarchetypeArtifactId=parancoe-webarchetype \
-DarchetypeVersion=2.0.1 \
-DgroupId=com.mycompany \
-DartifactId=testApp \
-DpackageName=com.mycompany.testapp

It will generate a new complete project ready for your next development. I repeat, complete, the new application is already working, you can build and deploy it on your application server and use it. You'll see a simple layout, administrative tasks, debug information in page (when deployed in development mode), user authentication and authorization, user management.

With a good IDE :) the start-up task is even easier. Watch this my previous, still valid, screen-cast.

Don't miss to read the new Parancoe Reference Guide, both in HTML and in PDF.

Have fun!

Monday, July 21, 2008

PDF Unencrypting

Updated 07/29/2008: added the copy of the bookmarks (index) from the original document.


Usually, when you buy a PDF book, it's encrypted and protected by a password. No problem, I agree with authors and publishers that need to protect their work, even if this technique is a very poor protection.

Unfortunately usually some portable readers, like my PRS-505, don't have encryption/password support, so you can't upload those PDFs on them.

So you need to unencrypt the PDF for reading it on the device, a perfectly legal operation if you legally bought the book.

The easiest way to unencrypt a PDF should be to use the pdftk command line tool:

pdftk abook.pdf input_pw your_password_here output abook_unencrypted.pdf

Unfortunately it always emits this error:

Error: Failed to open PDF file:
abook.pdf
OWNER PASSWORD REQUIRED, but not given (or incorrect)

Of course the password was correct and I tried with different combinations of input/owner/user password parameters. I think it's a bug of pdftk (version 1.41).

So I wrote a small Java program for unecrypting my files:

import com.lowagie.text.Document;
import com.lowagie.text.DocumentException;
import com.lowagie.text.pdf.PdfCopy;
import com.lowagie.text.pdf.PdfImportedPage;
import com.lowagie.text.pdf.PdfReader;
import com.lowagie.text.pdf.SimpleBookmark;
import java.io.FileOutputStream;
import java.io.IOException;

public class Unencrypt {
public static void main( String[] args )
throws IOException, DocumentException {
String inFile = args[0];
String outFile = args[1];
String password = args[2];
PdfReader pdfReader = new PdfReader(inFile, password.getBytes());
Document document = new Document();
PdfCopy copy = new PdfCopy(document, new FileOutputStream(outFile));
document.open();
for (int i = 1; i <= pdfReader.getNumberOfPages(); i++) {
PdfImportedPage importedPage = copy.getImportedPage(pdfReader, i);
copy.addPage(importedPage);
}
copy.setOutlines(SimpleBookmark.getBookmark(pdfReader));
document.close();
pdfReader.close();
}
}
For executing it, download this file, and type:

java -cp bpdf.jar com.benfante.bpdf.Unencrypt \
abook.pdf abook_unencrypted.pdf \
your_password_here

*WARNING*: I'm not responsible of the use you can do of this code. It's not intended as a tool for infringing copyrights, just for reading PDFs you legally owns on devices that don't support encrypting.

Friday, July 18, 2008

Pattern matching

Lo so, è un oszvnrioseae baanle, ma sepsso il nstoro celvelro fiouznna mtolo mliego di qlsaauisi cotemupr. Ad emspeio, a meno che il vrosto clevlreo non aibba qlachue pomeblra, dsvtoere eesrse peatentertfme in gdaro di lrggeee qeusto tteso, anhce se le lrtetee dllee plraoe, a parte la pirma e l'ulmita, snoo sttae messe alla rnfiusa. Quetso adcace perhcè qnaduo lgeaimgo in rtlaeà non psatemiro aioetntzne alle sngiole ltrteee, ma alla porala nel suo clspemoso.

Se volete giocare a ricombinare le parole di vostri testi, provate questo piccolo programmino che ho scritto:


Scarica questo file se vuoi dare un'occhiata ai sorgenti (rilasciati sotto Apache License, Version 2.0).

Questa e molte altre informazioni, e alcuni suggerimenti di miglioramento delle proprie capacità di apprendimento, le potete trovare in un interessante libro che sto leggendo: "Pragmatic Thinking and Learning" di Andy Hunt.

Update 08-14-2008: I just finished to read this book, of course on my PRS-505. It's a great book, a must-to-read if you need to be a continuous learner. And if you are in the IT business, of course you need to be. I'm a self-employed, mostly home-based, consultant and developer: the "Manage Focus" chapter is illuminating, and very helpful for trying to enhance the productivity of my work environment. In general the book is perfect for acquiring consciousness of your learning paths and deficiencies, with a lot of good tips for improving yourself. What I bought from the book? At present, I started writing "Morning Pages"; I already have a two monitor desktop, and as a Linux user I'm already used to virtual desktop; limiting "down" time and being conscious of it; caring of distractions; trying a better deliberate reading and acquiring of information.

Tuesday, July 8, 2008

Reading PDFs on a PRS-505

Update 07/28/2008: maybe the conversion PDF to LRF is obsolete on the PRS-505. With this firmware update the PDFs are rendered much much better (but still not better than the following conversion).




Since some months I'm an happy user of a Sony Portable Reader System (PRS-505).


It's a fantastic device, and actually I can comfortably read digital articles and books, instead of burning my eyes in front of a lightly monitor.

I can even use it with Linux, thanks to Calibre.

The PRS-505 can natively read PDF files, but the rendering is not always appropriate, and it's very difficult to read long text without headaches. So, I usually convert them from PDF to LRF.

Look at the result. On the left the original PDF. On the right the same page in the resulting LRF.


The conversion is very easy. You mainly need Ghostscript, for embedding all fonts in the PDF, and the pdflrf converter.

I wrote a simple script for easily run them with the correct parameters:

#!/bin/sh
# pdflrf_converter.sh by Lucio Benfante

gs -dSAFER -dNOPLATFONTS -dNOPAUSE -dBATCH -sDEVICE=pdfwrite \
-dCompatibilityLevel=1.4 -dPDFSETTINGS=/printer \
-dCompatibilityLevel=1.4 -dMaxSubsetPct=100 \
-dSubsetFonts=true -dEmbedAllFonts=true \
-sOutputFile=$1.embedding -f $1

pdflrf -r --rotation="0" --colors=8 -i $1.embedding -o $1.lrf

rm $1.embedding

Launch it with passing your PDF file as its single parameter:
pdflrf_converter.sh myBook.pdf

Please let me know if it's useful for you, or if you could find a better set of parameters for gs/pdflrf.

Thursday, March 20, 2008

Start a new Web project with the Parancoe Web meta-framework and NetBeans 6.1

Starting new Web project using the Parancoe meta-framework is very easy and fast. Even more if you are using a good IDE. Watch at this screencast, in which I create a new project with Parancoe and NetBeans 6.1.










Download the screen cast at the maximum resolution.