一个最简单的ajax请求
html页面内容
View Code
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>ajaxTest</title>
<script type="text/javascript">
var req;//XMLHttpRequest对象
function butClick(){
var id=document.getElementById("id").value;
var url="ajaxTestServlet?id="+id;
if(window.XMLHttpRequest){//IE
req=new XMLHttpRequest();
}else if(window.ActiveXObject){//其他浏览器
req=new ActiveXObject("Microsoft.XMLHTTP");
}
req.open("post",url,true);
req.onreadystatechange=callback;
req.send(null);
}
function callback(){
if(req.readyState==4){
if(req.status==200){
document.getElementById("id").value=req.responseText;
}
}
}
</script>
</head>
<body>
<input type="text" name="id" id="id" /><br>
<input type="button" value="click me!" onclick="butClick()">
</body>
</html>
servlet内容
View Code
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class AjaxTestServlet
*/
public class AjaxTestServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String id=request.getParameter("id");
System.out.println(id + "id");
if(id.equals("1")){
response.getWriter().write("1111111111");
}else{
response.getWriter().write("other.....");
}
}
}
最后别忘了在web.xml内配置servlet
View Code
<servlet>
<description></description>
<display-name>AjaxTestServlet</display-name>
<servlet-name>AjaxTestServlet</servlet-name>
<servlet-class>com.fengzexin.servlet.AjaxTestServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>AjaxTestServlet</servlet-name>
<url-pattern>/ajaxTestServlet</url-pattern>
</servlet-mapping>
