jQuery对Ajax的支持
- jQuery对Ajax进行封装，提供了$.ajax()方法
- 语法：$.ajax(options)
| 常用设置项 | 说明 |
|---|---|
| url | 发送请求地址 |
| type | 请求类型get|post |
| data | 向服务器传递的参数 |
| dataType | 服务器响应的数据类型 text|json|xml|html|jsonp|script |
| success | 接收响应时的处理函数 |
| error | 请求失败时的处理函数 |
实例代码
MusicServlet.java
package demo;
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;
import com.alibaba.fastjson.JSON;
/**
* Servlet implementation class MusicSetvlet
*/
@WebServlet("/music")
public class MusicServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public MusicServlet() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String songType = request.getParameter("songType");
System.out.println(songType);
List<String> song = new ArrayList<>();
if(songType.equals("流行歌曲")) {
song.add("稻香");
song.add("晴天");
song.add("告白气球");
}else if(songType.equals("经典歌曲")) {
song.add("千千阙歌");
song.add("傻女");
song.add("七友");
}else if(songType.equals("摇滚歌曲")) {
song.add("一块红布");
song.add("假行僧");
song.add("星长征路上的摇滚");
}
String json = JSON.toJSONString(song);
response.setContentType("text/html;charset=utf-8");
response.getWriter().println(json);
}
}
musicList.jsp
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Insert title here</title>
<style>
div {
text-align: center;
}
.mystyle {
30%;
cursor: pointer;
}
</style>
</head>
<body>
<div>
<input class="mystyle" type="button" value="流行歌曲"> <input
class="mystyle" type="button" value="经典歌曲"> <input
class="mystyle" type="button" value="摇滚歌曲">
</div>
<div id="divContent"></div>
<script type="text/javascript" src="js/jquery-3.4.1.js"></script>
<script type="text/javascript">
$(":button").click(function() {
var songType = this.value;
$(function() {
$.ajax({
"url" : "/ajax/music",
"type" : "get",
"data" : {
"songType" : songType
},
"dataType" : "json",
"success" : function(json) {
$("#divContent>span").remove();
$("#divContent>br").remove();
for (var i = 0; i < json.length; i++) {
var html = "<span>" + json[i] + "</span><br>";
$("#divContent").append(html);
}
},
"error" : function(xmlhttp, errorText){
console.log(xmlhttp);
console.log(errorText);
if(xmlhttp.status == "405"){
alert("无效的请求方式");
}else if(xmlhttp.status == "404"){
alert("未找到URL资源");
}else if(xmlhttp.status == "500"){
alert("服务器内部错误，请联系管理员");
}else{
alert("产生异常，请联系管理员");
}
}
})
})
})
</script>
</body>
</html>