Ajax imitate automatic prompts Baidu search box
Ah, ah, stay up late. Ajax learned today gave me the feeling is, "Wow" ajax good cool Oh, (the amount of back-end ... dog, come into contact with the charm of a large front-end), so late or go straight to. Let's go!
Baidu search tips box, I think we are all familiar with the, what it looks like I will not repeat them. Direct look at the code
We have to write a simple jsp page Look! Look like this
Here is the code:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!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>Test Baidu</title>
</head>
<body>
<!--
文本输入框
-->
<div id="serach">
<input type="text" name="text" id="text" />
<input type="submit" value="搜索" />
</div>
<!--
提示下拉框
-->
<div id="tips" style="display: none;
width: 171px; border: 1px solid pink";>
</div>
</body>
<script>
window.οnlοad=function(){
//获取文本输入框
var textElment = document.getElementById("text");
//获取下提示框
var div = document.getElementById("tips");
textElment.οnkeyup=function(){
//获取用户输入的值
var text = textElment.value;
//如果文本框中没有值，则下拉框被隐藏，不显示
if(text==""){
div.style.display="none";
return;
}
//获取XMLHttpRequest对象
var xhr = new XMLHttpRequest();
//编写回调函数
xhr.onreadystatechange=function(){
//判断回调的条件是否准备齐全
if(xhr.readyState==4){
if(xhr.status==200){
//取的服务器端传回的数据
var str = xhr.responseText;
//判断传回的数据是否为空,若是则直接返回，不显示
if(str==""){
return;
}
//我们将会在服务器端把数据用 , 隔开，当然这里也可以使用json
var result = str.split(",");
var childs = "";
//遍历结果集，将结果集中的每一条数据用一个div显示，把所有的div放入到childs中
for(var i=0; i<result.length;i++){
childs += "<div οnclick='Write(this)' οnmοuseοut='recoverColorwhenMouseout(this)' οnmοuseοver='changeColorwhenMouseover(this)'>"+result[i]+"</div>";
}
//把childs 这div集合放入到下拉提示框的父div中，上面我们以获取了
div.innerHTML=childs;
div.style.display="block";
}
}
}
//创建与服务器的连接
xhr.open("GET","${pageContext.request.contextPath}/test?text="+text);
//发送
xhr.send();
}
}
//鼠标悬停时改变div的颜色
function changeColorwhenMouseover(div){
div.style.backgroundColor="pink";
}
//鼠标移出时回复div颜色
function recoverColorwhenMouseout(div){
div.style.backgroundColor="";
}
//当鼠标带点击div时，将div的值赋给输入文本框
function Write(div){
//将div中的值赋给文本框
document.getElementById("text").value=div.innerHTML;
//让下拉提示框消失
div.parentNode.style.display="none";
}
</script>
</html>Look servlet:
package com.zhuxingyi.servlet;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 百度下拉框服务器端
*/
@WebServlet("/test")
public class test extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//获取前端传入的数据
String text = request.getParameter("text");
//我们在这里也还是向list集合中添加数据，模拟数据库的查询操作
System.out.println(text);
List<String> list =new ArrayList<>();
list.add("zhuxingyi");
list.add("zhuwei");
list.add("zhuyuanz");
list.add("zhude");
//将数据 转换成字符串
String str = "";
if(text.startsWith("z")) {
for(int i=0;i<list.size();i++) {
if(i>0) {
str+=",";
}
str+=list.get(i);
}
//将处理好的数据传回给客户端
response.getWriter().write(str);
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}Show you look at it, (very awkward, the landlord will not do gif map it, you take a look at a static view of the ...)
Enter the 'z' try it:
Clicking try it:
Ok, this is a simple imitation Baidu search box anymore than there are deficiencies you have to point out, oh, thank you. Thanks friends
