点击按钮后不报错但也没反应

package jqajax;
 
public class Song {
    private String name;
 
    public Song() {
        super();
        // TODO Auto-generated constructor stub
    }
 
    public Song(String name) {
        super();
        this.name = name;
    }
 
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }
     
}

package jqajax;
 
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;
 
/**
 * Servlet implementation class songlist
 */
@WebServlet("/songlist")
public class songlist extends HttpServlet {
    private static final long serialVersionUID = 1L;
        
    /**
     * @see HttpServlet#HttpServlet()
     */
    public songlist() {
        super();
        // TODO Auto-generated constructor stub
    }
 
    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        List<Song> list = new ArrayList<Song>();
        String x = request.getParameter("t");
        if(x.equals("流行歌曲")) {
            list.add(new Song("稻香"));
            list.add(new Song("晴天"));
            list.add(new Song("告白气球"));
        }else if(x.equals("经典歌曲")) {
            list.add(new Song("千千阙歌"));
            list.add(new Song("傻女"));
            list.add(new Song("七友"));
        }else if(x.equals("摇滚歌曲")) {
            list.add(new Song("一块红布"));
            list.add(new Song("假行僧"));
            list.add(new Song("新长征路上的摇滚"));
        }
    }
 
}

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<style type="text/css">
* {
    margin: 0;
    padding: 0;
    text-decoration: none;
}
 
#list {
    width: 99%;
    margin: 0 auto;
    overflow: hidden;
    text-align: center;
}
 
input[type=button] {
    width: 33%;
    height: 30px;
}
 
#container {
    text-align: center;
    width: 100%;
}
</style>
<script type="text/javascript" src="js/jquery-3.4.1.min.js"></script>
</head>
<body>
 
    <div id="list">
        <input type="button" value="流行歌曲" id="b1"> <input
            type="button" value="经典歌曲" id="b2"> <input type="button"
            value="摇滚歌曲" id="b3">
    </div>
    <div id="container"></div>
    <script type="text/javascript">
        $("#b1").click(function() {
                alert("aa");
            $.ajax({
                "url" : "/jqajax/songlist",
                "type" : "get",
                "data" : "t=流行歌曲",
                "dataType" : "json",
                "success" : function(json) {
                    alert("aa");
                    for (var i = 0; i < list.length; i++) {
                        $("#container").append(list[i].name + "</br>");
                    }
                }
            })
        });
        $("#b2").click(function() {
            $.ajax({
                "url" : "/jqajax/songlist",
                "type" : "get",
                "data" : "t=经典歌曲",
                "dataType" : "json",
                "success" : function(json) {
                    for (var i = 0; i < list.length; i++) {
                        $("#container").append(list[i].name + "</br>");
                    }
                }
            })
        });
        $("#b3").click(function() {
            $.ajax({
                "url" : "/jqajax/songlist",
                "type" : "get",
                "data" : "t=摇滚歌曲",
                "dataType" : "json",
                "success" : function(json) {
                    for (var i = 0; i < list.length; i++) {
                        $("#container").append(list[i].name + "</br>");
                    }
                }
            })
        });
    </script>
</body>
</html>