ajax简单实例


		ajax简单实例
（js内产生xmlHttpRequest，它和servlet交互返回xml显示在页面） 
---------------------------------AJAX.html------------------------------------------- 
<html> 
<head> 
  <title>AJAX.html</title> 
</head> 
<script type="text/javascript"> 
/*通过异步传输XMLHTTP发送参数到ajaxServlet，返回符合条件的XML文档*/ 
function getResult(){ 
  var url = "ajaxServlet?action=send"; 
  if (window.XMLHttpRequest){ 
   req = new XMLHttpRequest(); 
  }else if (window.ActiveXObject) 
  { 
   req = new ActiveXObject("Microsoft.XMLHTTP"); 
  } 
  if(req) 
  { 
   req.open("GET",url, true); 
   req.onreadystatechange = complete; 
   req.send(null); 
  } 
} 
/*分析返回的XML文档*/ 
function complete(){ 
  if (req.readyState == 4) 
  { 
   if (req.status == 200){ 
    var type = req.responseXML.getElementsByTagName("type_name"); 
    var str=new Array(); 
    for(var i=0;i<type.length;i++){ 
     str[i]=type[i].firstChild.data; 
     document.all[td].innerHTML+=str[i]+"<BR>"; 
    } 
   } 
  } 
} 
</script> 
<body onLoad="getResult()"> 
  <table width="80%" border="0" cellspacing="0" cellpadding="0"> 
   <tr> 
    <td id="td"> 
    </td> 
   </tr> 
  </table> 
</body> 
</html> 
---------------------------------ajaxServlet.java----------------------------------------------------- 
import java.io.IOException; 
import java.io.PrintWriter; 
import javax.servlet.ServletException; 
import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 
public class ajaxServlet extends HttpServlet{ 
private static final String CONTENT_TYPE = "text/xml; charset=gb2312"; 
public void init() throws ServletException{} 
public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException, IOException 
{ 
  response.setContentType(CONTENT_TYPE); 
  PrintWriter out = response.getWriter(); 
  String action = request.getParameter("action"); 
  if (("send").equals(action)) 
  { 
   StringBuffer sb = new StringBuffer("<type>"); 
   sb.append("<type_name>AA</type_name>"); 
   sb.append("<type_name>BB</type_name>"); 
   sb.append("<type_name>CC</type_name>"); 
   sb.append("<type_name>DD</type_name>"); 
   sb.append("</type>"); 
   out.write(sb.toString()); 
   out.close(); 
  } 
} 
} 
--------------------------------web.xml------------------------------------------------------ 
<?xml version = 1.0 encoding = UTF-8?> 
<!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd"> 
<web-app> 
<description>Empty web.xml file for Web Application</description> 
<servlet> 
  <servlet-name>ajax</servlet-name> 
  <servlet-class>ajaxServlet</servlet-class> 
</servlet> 
    <servlet-mapping> 
        <servlet-name>ajax</servlet-name> 
        <url-pattern>/ajaxServlet</url-pattern> 
    </servlet-mapping> 
</web-app>

补充：综合编程 , 其他综合 ,