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AJAX+Servlet實(shí)現(xiàn)的數(shù)據(jù)處理顯示功能示例

更新時(shí)間：2018年06月05日 11:25:27 作者：GreatNeyo

這篇文章主要介紹了AJAX+Servlet實(shí)現(xiàn)的數(shù)據(jù)處理顯示功能,結(jié)合實(shí)例形式分析了前臺(tái)ajax與后臺(tái)Servlet生成隨機(jī)數(shù)顯示的相關(guān)交互操作技巧,需要的朋友可以參考下

本文實(shí)例講述了AJAX+Servlet實(shí)現(xiàn)的數(shù)據(jù)處理顯示功能。分享給大家供大家參考，具體如下：

實(shí)現(xiàn)功能：在輸入框中輸入字符，用AJAX傳到后臺(tái)Servlet處理后加上隨機(jī)數(shù)，并返回到前臺(tái)顯示。

一、寫前臺(tái)jsp頁(yè)面index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
 <head>
  <title>My JSP 'index.jsp' starting page</title>
  <script type="text/javascript">
  /*
    ajax 的幾個(gè)步驟：
    1、建立XmlHttpRequest對(duì)象
    2、設(shè)置回調(diào)函數(shù)
    3、使用Open方法建立與服務(wù)器的連接
    4、向服務(wù)器發(fā)送數(shù)據(jù)
    5、在回調(diào)函數(shù)中針對(duì)不同響應(yīng)狀態(tài)進(jìn)行處理
  */
    var xmlHttp;
    function createXMLHttpRequest(){  //1建立XmlHttpRequest對(duì)象
      if(window.ActiveXObject){
        try{
          xmlHttp = new ActiveXObject("Microsoft.XMLHttp");
        }catch(e){
          alert("Error!!!");
        }
      }else{
        xmlHttp = new XMLHttpRequest();
      }
    }
    function showMes(){   //2設(shè)置回調(diào)函數(shù)
      if(xmlHttp.readyState==4){ //數(shù)據(jù)接收完成并可以使用
        if(xmlHttp.status==200){ //http狀態(tài)OK
        //5、在回調(diào)函數(shù)中針對(duì)不同響應(yīng)狀態(tài)進(jìn)行處理
          document.getElementById("sp").innerHTML = xmlHttp.responseText; //服務(wù)器的響應(yīng)內(nèi)容
        }else{
          alert("出錯(cuò)："+xmlHttp.statusText); //HTTP狀態(tài)碼對(duì)應(yīng)的文本
        }
      }
    }
    /**
    //這是GET方法傳送
    function getMes(){
      createXMLHttpRequest();
      var txt = document.getElementById("txt").value;
      var url="servlet/AjaxServlet?txt="+txt;
      url = encodeURI(url); //轉(zhuǎn)換碼后再傳輸
      xmlHttp.open("GET",url,true); //3使用Open方法建立與服務(wù)器的連接
      xmlHttp.onreadystatechange=showMes;
      xmlHttp.send(null); //4向服務(wù)器發(fā)送數(shù)據(jù)
    }
    */
    /**
    *這是post方法
    */
    function postMes(){
      createXMLHttpRequest();
      var txt = document.getElementById("txt").value;
      var url = "servlet/AjaxServlet";
      var params = "username="+txt;
    // alert(params);
      xmlHttp.open("POST",url,true);
      xmlHttp.setRequestHeader("Content-Type","application/x-www-form-urlencoded;charset=UTF-8");
      xmlHttp.send(params);
      xmlHttp.onreadystatechange = showMes;
    }
  </script>
 </head>
 <body>
  <input type="text" id="txt"/>
  <input type="button" value="query" onclick="postMes()" />
  <span id="sp"></span>
 </body>
</html>

二、寫后臺(tái)Servlet加random隨機(jī)數(shù)，關(guān)鍵代碼如下：

public void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    request.setCharacterEncoding("utf-8"); //用utf-8轉(zhuǎn)換獲得傳輸過來的碼
    response.setContentType("text/html");
    PrintWriter out = response.getWriter();
    String txt = request.getParameter("txt");
//   String tx = new String(txt.getBytes("iso-8859"),"utf-8");
    out.print("txt="+txt+Math.random());
    out.flush();
    out.close();
}
/**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {
    request.setCharacterEncoding("utf-8");
    response.setContentType("text/html;charset=UTF-8");
    PrintWriter out = response.getWriter();
    String username = request.getParameter("username");
//   String txt = new String(username.getBytes("ISO-8859-1"),"UTF-8");
    String txt = new String(username);
    out.print("txt="+txt+":"+Math.random());
    out.flush();
    out.close();
}

更多關(guān)于ajax相關(guān)內(nèi)容感興趣的讀者可查看本站專題：《jquery中Ajax用法總結(jié)》、《JavaScript中ajax操作技巧總結(jié)》、《PHP+ajax技巧與應(yīng)用小結(jié)》及《asp.net ajax技巧總結(jié)專題》

希望本文所述對(duì)大家ajax程序設(shè)計(jì)有所幫助。

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