JS+Ajax实现百度智能搜索框

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我是靠谱客的博主霸气犀牛，最近开发中收集的这篇文章主要介绍JS+Ajax实现百度智能搜索框，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

首先浏览实现后的结果，输入一个a之后会出现包含a的下拉列表，当我们点击某一个的时候，搜索框中就会出现点击的值。实现所需要的主要是ajax+js。

前端search.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8" 
  pageEncoding="UTF-8"%> 
<html> 
<head> 
<title>Insert title here</title> 
<script src="js/jquery.min.js"></script> 
<style type="text/css"> 
  *{ 
   margin: 0 auto; 
   padding: 0; 
  } 
  li{ 
    margin:0; 
    height: 20px; 
    width: 200px; 
    list-style: none; 
  } 
  /* #c li:HOVER{ 
   background-color: #F9F9F9; 
  } */ 
  .onmouse{ 
   background-color: #F9F9F9; 
  }  
  .outmouse{ 
   background-color:white; 
  } 
  #contain{ 
   width: 50%; 
  } 
</style> 
<!-- jquery --> 
<script type="text/javascript"> 
var xmlHttp; 
  function getMoreContents() { 
  var content=document.getElementById("keyword"); 
  if(content.value==""){ 
    ClearContent(); 
    return;//如果不设置，传到后台的是空值，所有的值都会被输出 
  } 
  xmlHttp=creatXMLHttp(); 
  //alert(xmlHttp); 
  //要给服务器发送数据 
  var url="searchServlet?keyword="+escape(content.value); 
  xmlHttp.open("GET",url,true); 
  xmlHttp.onreadystatechange=callback; 
  xmlHttp.send(null); 
} 
  //获取XMLHttp对象 
 function creatXMLHttp() { 
  var xmlHttp; 
  if(window.XMLHttpRequest){ 
    xmlHttp=new XMLHttpRequest(); 
  } 
  if(window.ActiveXObject) 
  { 
    xmlHttp=new ActiveXObject("Microsoft.XMLHTTP"); 
    if(!xmlHttp){ 
      xmlHttp=new ActiveXOject("Msxml2.XMLHTTP"); 
    } 
  } 
  return xmlHttp; 
} //获取XMLHttp对象 
  function callback() { 
  if(xmlHttp.readyState==4 && xmlHttp.status==200){ 
     var result=xmlHttp.responseText; 
     //解析数据 
     var json=eval("("+result+")"); 
     //动态显示数据，线束数据在输入框对的下面 
     setContent(json); 
  } 
} 
//设置关联数据的展示 
function setContent(contents) { 
  ClearContent(); 
  var size=contents.length; 
  for(var i=0;i<size;i++) 
    { 
     var nextNode=contents[i];//json格式的第i个数据 
     var li =document.createElement("li"); 
     li.onmouseover=function(){ 
       this.className="onmouse"; 
       document.getElementById("keyword").value=this.innerHTML; 
     } 
     li.onmouseout=function(){ 
       this.className="outmouse"; 
     } 
     var text=document.createTextNode(nextNode); 
     li.appendChild(text); 
     document.getElementById("c").appendChild(li); 
    } 
} 
//清空数据 
function ClearContent() { 
  document.getElementById("c").innerHTML=""; 
} 
//当控件失去焦点时，清空数据 
function outFouce() { 
  ClearContent(); 
} 
//获得焦点时， 
</script> 
</head> 
<body> 
  <div id="contain"> 
    <div style="height: 20px;"> 
      <input type="text" id="keyword" style="size:50px;" onkeyup="getMoreContents()" onblur="outFouce()" onfocus="getMoreContents()">  
      <input type="button" id="bu" value="百度一下" style=""> 
    </div> 
    <div id="popDiv"> 
     <ul id="c"> 
       <li></li> 
     </ul> 
    </div> 
  </div> 
</body> 
</html>

后台searchServlet.Java

package search; 
import java.io.IOException; 
import java.util.ArrayList; 
import java.util.List; 
import net.sf.json.JSONArray; 
import javax.servlet.ServletException; 
import javax.servlet.annotation.WebServlet; 
import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 
/** 
 * Servlet implementation class searchServlet 
 */ 
@WebServlet("/searchServlet") 
public class searchServlet extends HttpServlet { 
  private static final long serialVersionUID = 1L; 
  static List<String> datas=new ArrayList<String>(); 
  static {//假数据，模拟数据库读取 
    datas.add("ajax"); 
    datas.add("bjax"); 
    datas.add("ajaxfd"); 
    datas.add("bfvd"); 
    datas.add("dafdx"); 
    datas.add("fdax"); 
    datas.add("ahg"); 
    datas.add("ddx"); 
  } 
  /** 
   * @see HttpServlet#HttpServlet() 
   */ 
  public searchServlet() { 
    super(); 
    // TODO Auto-generated constructor stub 
  } 
  /** 
   * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) 
   */ 
  protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 
    // TODO Auto-generated method stub 
    doPost(request, response); 
  } 
  /** 
   * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) 
   */ 
  protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 
    // TODO Auto-generated method stub 
    request.setCharacterEncoding("UTF-8"); 
    response.setCharacterEncoding("UTF-8"); 
    String keyword=request.getParameter("keyword"); 
    //System.out.println(keyword); 
    List<String> listdata= getData(keyword); 
  // 返回json,以流的形式写到前台 
    response.getWriter().write(JSONArray.fromObject(listdata).toString()); 
  } 
  //获取假数据中符合条件的值 
  public List<String> getData(String keyword) 
  { 
    List<String> list=new ArrayList<String>(); 
    for(String data:datas) 
    { 
      if(data.contains(keyword)){ 
        list.add(data); 
      } 
    } 
    return list; 
  } 
}

xml配置

<span style="font-size:18px;"><strong><?xml version="1.0" encoding="UTF-8"?> 
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1"> 
 <servlet> 
  <servlet-name>searchServlet</servlet-name> 
  <servlet-class>search.searchServlet</servlet-class> 
 </servlet> 
 <servlet-mapping> 
  <servlet-name>searchServlet</servlet-name> 
  <url-pattern>/search/searchServlet</url-pattern> 
 </servlet-mapping> 
 <display-name>DropMeum</display-name> 
 <welcome-file-list> 
  <welcome-file>index.html</welcome-file> 
  <welcome-file>index.htm</welcome-file> 
  <welcome-file>index.jsp</welcome-file> 
  <welcome-file>default.html</welcome-file> 
  <welcome-file>default.htm</welcome-file> 
  <welcome-file>default.jsp</welcome-file> 
 </welcome-file-list> 
</web-app></strong></span>

目录结构