ajax 三种实现方法实例代码

package ajax.servlet; 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; /**  * Ajax例子后台处理程序  * @author bing  * @version 2011-07-07  *  */public class TestAjaxServlet extends HttpServlet {  public void doGet(HttpServletRequest request, HttpServletResponse response)    throws ServletException, IOException {   response.setContentType("text/html;charset=utf-8");   PrintWriter out = response.getWriter();   String name = request.getParameter("name");   String age = request.getParameter("age");   System.out.println("{/"name/":/"" + name + "/",/"age/":/"" + age + "/"}");   out.print("{/"name/":/"" + name + "/",/"age/":" + age + "}");   out.flush();   out.close();  }  public void doPost(HttpServletRequest request, HttpServletResponse response)    throws ServletException, IOException {   doGet(request,response);  } }

<div id="show">显示区域</div> <div id="parameters">  name:<input id="name" name="name" type="text" /><br />  age:<input id="age" name="age" type="text" /><br /> </div> 

<script type="text/javascript" src="prototype.js"></script>  <script type="text/javascript">   function prototypeAjax()   {     var url = "servlet/testAjax";//请求URL   var params = Form.serialize("parameters");//提交的表单   var myAjax = new Ajax.Request(   url,{    method:"post",// 请求方式    parameters:params, // 参数    onComplete:pressResponse, // 响应函数    asynchronous:true  });   $("show").innerHTML = "正在处理中...";   }   function pressResponse(request)   {   var obj = request.responseText; // 以文本方式接收   $("show").innerHTML = obj;   var objJson = request.responseText.evalJSON(); // 将接收的文本用解析成Json格式   $("show").innerHTML += "name=" + objJson['name'] + " age=" + objJson['age'];   } </script> <input id="submit" type="button" value="提交" onclick="prototypeAjax()" /><br />

<script type="text/javascript" src="jquery-1.3.2.min.js"></script> <script type="text/javascript" src="json2.js"></script> <input id="submit" type="button" value="提交" /><br /> <script type="text/javascript">   function jqueryAjax()    {     var user={"name":"","age":""};     user.name= $("#name").val();     user.age=$("#age").val();    var time = new Date();      $.ajax({       url: "servlet/testAjax?time="+time,       data: "name="+user.name+"&age="+user.age,       datatype: "json",//请求页面返回的数据类型       type: "GET",       contentType: "application/json",//注意请求页面的contentType 要于此处保持一致       success:function(data) {//这里的data是由请求页面返回的数据      var dataJson = JSON.parse(data); // 使用json2.js中的parse方法将data转换成json格式      $("#show").html("data=" + data + " name="+dataJson.name+" age=" + dataJson.age);       },       error: function(XMLHttpRequest, textStatus, errorThrown) {       $("#show").html("error");      }     });    }   $("#submit").bind("click",jqueryAjax); // 绑定提交按钮  </script>

<script type="text/javascript">   var xmlhttp;   function XMLHttpRequestAjax()   {    // 获取数据    var name = document.getElementById("name").value;     var age = document.getElementById("age").value;    // 获取XMLHttpRequest对象    if(window.XMLHttpRequest){    xmlhttp = new XMLHttpRequest();    }else if(window.ActiveXObject){    var activxName = ["MSXML2.XMLHTTP","Microsoft.XMLHTTP"];     for(var i = 0 ; i < activexName.length; i++){     try{      xmlhttp = new ActiveXObject(activexName[i]);      break;     }catch(e){}    }    }     xmlhttp.onreadystatechange = callback; //回调函数     var time = new Date();// 在url后加上时间，使得每次请求不一样     var url = "servlet/testAjax?name="+name+"&age="+age+"&time="+time;     xmlhttp.open("GET",url,true); // 以get方式发送请求     xmlhttp.send(null); // 参数已在url中，所以此处不需要参送   }    function callback(){     if(xmlhttp.readyState == 4){      if(xmlhttp.status == 200){ // 响应成功      var responseText = xmlhttp.responseText; // 以文本方式接收响应信息      var userdiv = document.getElementById("show");      var responseTextJson = JSON.parse(responseText); // 使用json2.js中的parse方法将data转换成json格式      userdiv.innerHTML=responseText + " name=" + responseTextJson.name + " age=" + responseTextJson.age;     }    }     } </script> <input id="submit" type="button" value="提交" onclick="XMLHttpRequestAjax()" /><br />