AJAX学习笔记8 跨域问题及解决方案_biubiubiu0706的博客-CSDN博客
其实就一个功能
搜索联想
自动补全
键盘按下事件keydown 键盘弹起事件keyup 做模糊查询
<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>ajax实现搜索联想自动补全</title><style type="text/css">.userInput{width: 300px;height: 25px;font-size: 20px;margin-left: 20px;padding-left: 5px;}.showDataDiv{width: 300px;margin-left: 20px;border: 1px solid lightblue;background-color: antiquewhite;}.showDataDiv p{padding-left: 5px;margin-top: 3px;margin-bottom: 5px;}.showDataDiv p:hover{/*加小手*/cursor: pointer;border:1px blue solid;background-color: aliceblue;}</style>
</head>
<body>
<input type="text" class="userInput">
<div class="showDataDiv"><p>北京疫情最新情况</p><p>北京天气</p><p>北京时间</p><p>北京房产</p><p>北京美女</p>
</div>
</body>
</html>
加个display:none;就隐藏掉
插入数据库
引入fastjson,mysql 依赖
后端代码
import com.alibaba.fastjson.JSON;import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;/*** @author hrui* @date 2023/9/7 9:53*/
@WebServlet("/getAny")
public class GetAnyServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {String keywords = req.getParameter("keywords");Connection conn=null;PreparedStatement ps=null;ResultSet rs=null;List<Map> list=new ArrayList<>();try {Class.forName("com.mysql.cj.jdbc.Driver");conn = DriverManager.getConnection("xxx", "xxx", "xxx");String sql="select id,content from t_ajax where content like ?";ps=conn.prepareStatement(sql);ps.setString(1, keywords+"%");rs = ps.executeQuery();while(rs.next()){String id = rs.getString("id");String content = rs.getString("content");Map<String,String> map=new HashMap<>();map.put("id", "id");map.put("content", content);list.add(map);}} catch (ClassNotFoundException | SQLException e) {e.printStackTrace();}finally {if(rs!=null){try {rs.close();} catch (SQLException e) {e.printStackTrace();}}if(ps!=null){try {ps.close();} catch (SQLException e) {e.printStackTrace();}}if(conn!=null){try {conn.close();} catch (SQLException e) {e.printStackTrace();}}}resp.setContentType("text/html;charset=utf-8");PrintWriter writer = resp.getWriter();String s = JSON.toJSONString(list);writer.print(s);}
}前端
<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>ajax实现搜索联想自动补全</title><style type="text/css">.userInput{width: 300px;height: 25px;font-size: 20px;margin-left: 20px;padding-left: 5px;}.showDataDiv{width: 300px;margin-left: 20px;border: 1px solid lightblue;background-color: antiquewhite;display:none;}.showDataDiv p{padding-left: 5px;margin-top: 3px;margin-bottom: 5px;}.showDataDiv p:hover{/*加小手*/cursor: pointer;border:1px blue solid;background-color: aliceblue;}</style>
</head>
<body>
<script type="text/javascript">/*不使用JQuery*/window.onload=()=>{document.getElementById("keywords").onkeyup=()=>{let xhr=new XMLHttpRequest();xhr.onreadystatechange=()=>{if(xhr.readyState==4){if(xhr.status>=200&&xhr.status<300){//[{"id":"xxx","content":"xxxx"},{"id":"xxx","content":"xxxx"}]const json=JSON.parse(xhr.responseText)const html=""for(let i=0;i<json.length;i++){html+="<p onclick='setInput(\""+json[i].content+"\")'>"+json[i].content+"</p>"}document.getElementById("showDataDiv").innerHTML=html//将div显示出来document.getElementById("showDataDiv").style.display="block"}}}console.log(this.value)xhr.open("get","/d/getAny?keywords="+this.value,true)xhr.send()}}function setInput(value){document.getElementById("keywords").value=value//将div隐藏document.getElementById("showDataDiv").style.display="none"}
</script>
<input type="text" class="userInput" id="keywords">
<div class="showDataDiv">
<!-- <p>北京疫情最新情况</p>-->
<!-- <p>北京天气</p>-->
<!-- <p>北京时间</p>-->
<!-- <p>北京房产</p>-->
<!-- <p>北京美女</p>-->
</div>
</body>
</html>
