GWT Java AJAX Programming

simon_kehler writes "The Google Web Toolkit (GWT) is a Java AJAX framework that provides an easy to use programming paradigm for web developers using the Java programming language. It is one of the more recent entrants into this field, but has been gaining a lot of traction and popularity. GWT Java AJAX Programming authored by Prabhakar Chaganti and published by Packt Publishing addresses the use of GWT to build ajaxified user interfaces. The author gently introduces the reader to GWT and then leads the reader through a series of tasks, each of which shows how to perform an useful action with GWT." Read below for Simon's review. GWT Java AJAX Programming author Prabhakar pages 240 publisher Packt Publishing rating 8 reviewer simon Kehle ISBN 1847191002 summary A great book for learning the different facets and features of GWT

I am a software architect working for a startup that is evaluating the use of GWT for a new project. I lead a team of experienced Java developers that are comfortable working with Swing and have reasonable familiarity with Struts. We have looked on with envy at all the nice things you could do with the AJAX integration built into web frameworks in languages such as PHP and Ruby. When I came across GWT we decided to take it for a spin and see if your team would be comfortable using it. The documentation that comes with the GWT download is a bit sparse. I was looking for a more in depth intro to the framework and came across this book. this seems to be the first print book on the GWT framework.

The book is divided into ten chapters. An introduction to GWT and its download and setup is provided in the first chapter. The author then shows how to create random quote GWT application in chapter 2. This is a nice example that immediately gives you the flavor of what its like to work with GWT. It shows you the steps involved in writing and running a simple GWT app. Chapter 3 details the service interfaces that you need to create as a part of any GWT application. These are the heart of how the AJAX mechanism works in this framework. Chapters 4-6 go through a lot of tasks that show you how to create increasingly complex user interfaces using the GWT framework. Chapter 7 deals with creating custom widgets that can be shared across applications. Unit testing for GWT applications is covered in chapter 8 (Yes, you can unit test your AJAX apps!). I18N and client XML support are dealt with in chapter 9 and finally chapter 10 shows how to deploy your applications.

This book moves along at a fairly rapid pace and is a quick read. The examples chosen for the tasks are well thought out and show different features in GWT. There are several really cool and innovative examples in this book: Password strength checker, uses colored check boxes to visually show the strength of a password. A very different way of using a check box. Dynamic Lists, change list entries as selections change. Flickr label, recreates the cool label widget that was made famous by Flickr. Sticky Notes, you create post it notes in your browser and drag them around to place them as you want (uses GWT drag support.) Mona Lisa jigsaw puzzle, rearrange Mona Lisa (uses GWT drag support.) Moo.fx, uses moo.fx javascript library for effects (uses JSNI.) Color Selector, integrates Rico Javascript library into GWT (uses JSNI.) Calendar, a very cool mac os x like calendar widget (Creates a compound widget.) Weather, another widget (creates a compound widget.) I18N, displays the country flag based on the locale (uses i18n support.)

I had played around a bit with GWT before. So some of the things in the book were not new to me, but there were several things that I found very useful. GWT provides a way to integrate Java and Javascript (you can call into Java from JS or from JS to Java) called JSNI (Javascript Native interface). The JSNI examples in this book showed how to integrate with moo.fx, Rico and scriptaculous libraries. This was great as we have some homegrown Javascript libs that we would like to continue to use even when we move to GWT. If we can try to hook those in and call them from GWT, that would be sweet! The ability to create widgets that can be shared across applications is very important to our project. The author creates two widgets in chapter 7 — calendar and weather. Both of these were very cool and reminded me of my mac desktop widgets! The weather widget uses Yahoo's weather service to retrieve the information that is displayed. Again, very nicely done. The ability to unit test is another thing that is crucial for us. GWT leverages and extends JUnit to provide this support. However, this is one of the parts of GWT that people do not seem to be using much. Searching on the GWT forums reveals as much confusion about this topic. This book contains a chapter that shows how to unit test a GWT application. The examples are quite simple, but the creation of test suites was a good one, as I had struggled with that before. I really liked the author's coverage of deployment. He first shows how to manually deploy a GWT application. this gives you a feel for whats involved and what's going where. Then he automates that using ant and finally shows how to deploy from within eclipse. This is very useful as I have tripped over deployment before.

Overall, this is a well written book that was very useful to our team. There were a few examples that we had implemented differently than the author — table sorting, paging and in place editing of the tree nodes. I18N is a big topic and the author covers only one way to use it. It would have been nice to have a complete chapter devoted to that topic, as this is a topic of particular interest to us as we work with a multitude of languages. This is a very developer oriented book and assumes that you know Java, HTML, some Javascript and some CSS. Of course if you did not know those topics, you probably wouldn't be too interested in GWT! This is not a book that dives into the internals of how GWT works or tries to impress you with all the nitty gritty of the GWT architecture. The author provides you with ways in which you can accomplish most common tasks that require GWT. They may not be the only way to do things using GWT but it gets you comfortable using GWT and thinking about how you would actually apply it for your problem. I really enjoyed reading this book and its focus on the practical side of using GWT.

You can purchase GWT Java AJAX Programming from amazon.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.

Comments

AJAX Is Not a Panacea

[curmudgeon99]

Having implemented a few AJAX-enhanced webapps, I can say that they are not a panacea. You need to use AJAX to do tiny things and if you don't you will find your application bogs down the same way a Swing app does if you use the GUI-painting thread for Event handling.

Re:AJAX Is Not a Panacea

[Hamilton Publius]

Global Warming Heresy
by Walter Williams (March 27, 2007)

Most climatologists agree that the earth's temperature has increased about a degree over the last century. The debate is how much of it is due to mankind's activity. Britain's Channel 4 television has just produced "The Great Global Warming Swindle," a documentary that devastates most of the claims made by the environmentalist movement. The scientists interviewed include top climatologists from MIT and other prestigious universities around the world. The documentary hasn't aired in the U.S., but it's available on the Internet. (http://www.youtube.com/watch?v=XttV2C6B8pU)

Among the many findings that dispute environmentalists' claims are: Manmade carbon dioxide emissions are roughly 5 percent of the total; the rest are from natural sources such as volcanoes, dying vegetation and animals. Annually, volcanoes alone produce more carbon dioxide than all of mankind's activities. Oceans are responsible for most greenhouse gases. Contrary to environmentalists' claims, the higher the Earth's temperature, the higher the carbon dioxide levels. In other words, carbon dioxide levels are a product of climate change. Some of the documentary's scientists argue that the greatest influence on the Earth's temperature is our sun's sunspot activity. The bottom line is, the bulk of scientific evidence shows that what we've been told by environmentalists is pure bunk.

Throughout the Earth's billions of years there have been countless periods of global warming and cooling. In fact, in the year 1,000 A.D., a time when there were no SUVs, the Earth's climate was much warmer than it is now. Most of this century's warming occurred before 1940. For several decades after WWII, when there was massive worldwide industrialization, there was cooling.

There's a much more important issue that poses an even greater danger to mankind. That's the effort by environmentalists to suppress disagreement with their view. According to a March 11 article in London's Sunday Telegraph, Timothy Ball, a former climatology professor at the University of Winnipeg in Canada, has received five death threats since he started questioning whether man was affecting climate change. Richard Lindzen, professor of Atmospheric Science at MIT, said, "Scientists who dissent from the alarmism have seen their funds disappear, their work derided, and themselves labeled as industry stooges." Nigel Calder, a former editor of New Scientist, said, "Governments are trying to achieve unanimity by stifling any scientist who disagrees. Einstein could not have got funding under the present system."

Suppressing dissent is nothing new. Italian cosmologist Giordano Bruno taught that stars were at different distances from each other surrounded by limitless territory. He was imprisoned in 1592, and eight years later he was tried as a heretic and burned at the stake. Because he disagreed that the Earth was the center of the universe, Galileo was ordered to stand trial on suspicion of heresy in 1633. Under the threat of torture, he recanted and was placed under house arrest for the rest of his life.

Today's version of yesteryear's inquisitors include people like the Weather Channel's Dr. Heidi Cullen, who advocates that the American Meteorological Society (AMS) strip their seal of approval from any TV weatherman expressing skepticism about the predictions of manmade global warming. Columnist Dave Roberts, in his Sept. 19, 2006, online publication, said, "When we've finally gotten serious about global warming, when the impacts are really hitting us and we're in a full worldwide scramble to minimize the damage, we should have war crimes trials for these bastards -- some sort of climate Nuremberg."

There are literally billions of taxpayer dollars being handed out to global warming alarmists, not to mention their dream of controlling our lives. Their agenda is threatened by dissent. They have the politician's ear; not we, who will suffer if they have their way.

mod dOwn

[Anonymous Coward]

hapless *BSD similarl7 grisl7 in time. For all