先把链接放在blog上,明天抽时间研究一下.如果好用我会补上介绍.

http://sourceforge.net/projects/googlipse/ 

1. Get whatever data you need from the Web form.
2. Build the URL to connect to.
3. Open a connection to the server.
4. Set up a function for the server to run when it's done.
5. Send the request.

This is the basic step for every Ajax apllication.

function callServer() { // Get the city and state from the web form var city = document.getElementById("city").value;
var state = document.getElementById("state").value;
// Only go on if there are values for both fields
if ((city == null) || (city == "")) return;
if ((state == null) || (state == "")) return; // Build the URL to connect to
var url = "/scripts/getZipCode.php?city=" + escape(city) + "&state=" + escape(state); // Open a connection to the server
xmlHttp.open("GET", url, true);

// Setup a function for the server to run when it's done
xmlHttp.onreadystatechange = updatePage;

// Send the request
xmlHttp.send(null);
}

function updatePage() {

if (xmlHttp.readyState == 4) {
var response = xmlHttp.responseText; document.getElementById("zipCode").value = response;
}
}

Following code will create a XMLHttpRequest object independently with type of browser

/* Create a new XMLHttpRequest object to talk to the Web server */
var xmlHttp = false;
/*@cc_on @*/
/*@if (@_jscript_version >= 5)
try {
xmlHttp = new ActiveXObject(“Msxml2.XMLHTTP”);
} catch (e) {
try {
xmlHttp = new ActiveXObject(“Microsoft.XMLHTTP”);
} catch (e2) {
xmlHttp = false;
}
}
@end @*/

if (!xmlHttp && typeof XMLHttpRequest != ‘undefined’) {
xmlHttp = new XMLHttpRequest();
}

1. Create a variable, xmlHttp, to reference the XMLHttpRequest object that you will create.
2. Try and create the object in Microsoft browsers.
3. If xmlHttp still isn’t set up, create the object in a non-Microsoft way.

1.什么是GWT?
GWT的全称叫做Google Web Toolkit,是Google API计划中的一下项目,可以把它想像成一个compiler.

2.如果使用GWT?
首先需要熟悉一下Google Web Toolkit的class reference.
然后就可以用GWT中提供的projectCreator创建project, applicationCreator创建一个application.
一个application就是一个单独的java class, project是由一个或多个application组成的.
在经过GWT compile过以后,每个project就会被编译成一系列html文件和一个javascript程序.

3.个人评论:
因为使用了java,所以编程规范化,代码可读性提高.对于象我这样java programmer带来了很多方便.
但是有一点让我有点头疼,就是美工问题.要使用GWT做出漂亮的界面,需要大量CSS知识,而这正是我所缺少的,以前一直认为CSS只是起到辅助性作用,可到了现在知道这个认识是错误的.