Java-based Ajax Tool-GWT

First download GWT, http://code.google.com/webtoolkit /;

Run-> cmd to create a project folder: C:/> mkdir myproject;

Set Path: C:/> set Path = % java_home %/bin; % gwt_home %;

The applicationcreator. CMD command supports the following syntax:

ApplicationCreator [-eclipse projectName] [-out dir] [-overwrite] [-ignore] className

Go to the myproject directory and run projectcreator-Eclipse myproject;

Continue executing applicationcreator-Eclipse myproject com. mycompany. Client. myapplication;

In this case, runMyapplication-shell will see the Google Web Toolkit development shell and wrapper HTML for myapplication two Google interfaces, and there is a simple button to test in the latter; ExecuteMyapplication-compile will be compiled;

Start eclipse, import an existing project, and select myproject to view the complete structure directory of the GWT application :)

Among them, the com. mycompany. Client. myapplication class is the page layout program. I changed it and added

Frame, with a result similar to the registered user entering the user name and prompting whether the user name is occupied, the Code is as follows:

Package com. mycompany. client;

Import com. Google. GWT. Core. Client. entrypoint;
Import com. Google. GWT. User. Client. UI. Button;
Import com. Google. GWT. User. Client. UI. clicklistener;
Import com. Google. GWT. User. Client. UI. label;
Import com. Google. GWT. User. Client. UI. rootpanel;
Import com. Google. GWT. User. Client. UI. widget;
Import com. Google. GWT. User. Client. window;
Import com. Google. GWT. User. Client. UI. frame;
Import com. Google. GWT. User. Client. UI. textbox;
Import com. Google. GWT. User. Client. UI .*;

/**
* Entry point Classes define <code> onmoduleload () </code>.
*/
Public class myapplication implements entrypoint {

/**
* This is the entry point method.
*/
Public void onmoduleload (){
Final button = new button ("Click me ");
Final label Label = new label ();
Final label label1 = new label ();
// Make a new frame, and point it at Google.
Frame frame = new frame ("http://www.google.com /");

// Add it to the root panel.
Rootpanel. Get (). Add (FRAME );

Final textbox TB = new Textbox ();
TB. addfocuslistener (New focuslistener (){
Public void onfocus (widget sender ){
}
Public void onlostfocus (widget sender ){
If (Tb. gettext (). Equals ("Ryan "))

Label1.settext ("Welcome! ");


Else
Label1.settext ("error! ");
}
});

Rootpanel. Get (). Add (TB );

Rootpanel. Get (). Add (label1 );

Button. addclicklistener (New clicklistener (){
Public void onclick (widget sender ){
If (Label. gettext (). Equals (""))
{Label. settext ("Hello world! ");
Window. Alert ("ajax ");
}
Else
Label. settext ("");
}
});

// Assume that the host HTML has elements defined whose
// IDs are "slot1", "slot2". In a real app, you probably wocould not want
// To hard-code IDs. Instead, you cocould, for example, search for all
// Elements with a participant CSS class and replace them with widgets.
//
Rootpanel. Get ("slot1"). Add (button );
Rootpanel. Get ("slot2"). Add (Label );
}
}

After modification, compile myapplication-compileand test myapplication.html in IE,

You can also execute myapplication-shell and use the debugger that comes with GWT to view the effect.

In short, GWT implements a wide range of Ajax effects using pure Java. GWT contains various HTML components and uses Java

The traditional event processing mechanism can be quickly used by people familiar with Java.