Saturday, March 28, 2009


EXT-GWT is a commercial GWT extension tools.

Recently, I am playing with it and I am impressed with the Web Desktop feature provided.

1 big advantage over GWT-EXT is Ext GWT is a Java implementation that does not use any external javascript and fully leverages the GWT API. This mean, potentially, it will load much faster than GWT-EXT.

My experience so far is, EXT-GWT load way faster than GWT-EXT.

Also, EXT-GWT support for Java 1.5 features, including generics, enums, and varargs.

Friday, March 20, 2009

IE 8 is out

Finally, IE 8 is officially released. You can download here

The beta IE version is rather disappointing. Sometime, for no reason, it will went into spinning.

Hopefully, this latest version will have more improvement.

Cnet review of IE8

I am amazed IE 8 does gain 30% of browser market share for MS. In overall, IE controls 67.55, FireFox controls 21.77%. See report here.

Monday, March 9, 2009


GWT-EXT-UX give extra widget for development. It provides cool widget such as UploadDialog. Due to lack of documentation of GWT-EXY-UX, and you are not familiar with GWT, you may encount null error when doing, ie

UploadDialog dialog = new UploadDialog("Upload a file");

Gives error

'$wnd.Ext.ux.UploadDialog.Dialog' is null or not an object

To fix this, give a try with the following

Also, visit the following

Hopefully, these tips helsp

Sunday, March 1, 2009

GWT - Javascript to GWT calls

JavaScipt and GWT interoperation are base on JSNI (JavaScript Native Interface)

Note: A JSNI comment block begins with the exact token /*-{ and ends with the exact token }-*/.

Here is an example of JSNI in GWT

public static native void alert(String msg) /*-{



Tips: When accessing the browser's window and document objects from JSNI, you must reference them as $wnd and $doc, respectively.

JSNI's param-signature follows Java data type declaration

For example myMethod(IFLjava/lang/String;)(); refers to this methoda has 3 parameters of Integer, Float and String

Consider the following which generate a HTML code, register a JS method and provide a call back

Add genHtml() to a Panel. Ie, panel.setHtml(genHtml()); If you onClick to the link, it will call onLinkClicked. This way, you can interact with your GWT application


GWT-EXT provides a API for mapping. It uses Mapstraction API to provide multiple map supports. These are the maps supported:

FreeEarthMap, GoogleMap, Map24Map, MapQuestMap, MicrosoftMap, MultiMap, OpenLayersMap, OpenStreetMap, YahooMap

Also, I am not going to do a tutorial here as there are many links available.

Check this link It provides you a headstart on how to create Map with GWT-EXT Map API.

Hadoop - How to setup a Hadoop Cluster

Below is a step-by-step guide which I had used to setup a Hadoop Cluster Scenario 3 VMs involved: 1) NameNode, ResourceManager - Host...