为什么会报500错误呢？

相关代码：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="/js/axios.js"></script>
</head>
<body>
<div id="container"></div>
<script>
    // axios.get("/news", {params: {"t": "pypl"}}).then((response) => {
    //     console.log(response)
    //     var newsList = response.data
    //     for (let i = 0; i < newsList.length; i++) {
    //         var news = newsList[i]
    //         let container = document.getElementById("container");
    //         container.innerHTML = container.innerHTML + "<h1>" + news.title + "</h1>"
    //     }
    // }).catch((error) => {
    //     console.log(error)
    // })

    // const params = new URLSearchParams()
    // params.append("t", "pypl")
    // params.append("t", "abc")
    // axios.post("/news", params)
    axios.post("/news", "t=pypl&l=abc",
        {headers: {"content-type": "application/x-www-form-urlencoded"}})
        .then((response) => {
            console.respnose
            var newsList = response.data
            for (let i = 0; i < newsList.length; i++) {
                var news = newsList[i]
                let container = document.getElementById("container");
                container.innerHTML = container.innerHTML + "<h1>" + news.title + "</h1>"
            }
        })
        .catch((error) => {
            console.log(error)
        });
</script>
</body>
</html>

相关代码：

package com.imooc.servlet;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.imooc.entity.News;

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.util.ArrayList;
import java.util.List;

@WebServlet("/news")
public class NewsServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String t = request.getParameter("t");
        List<News> list = new ArrayList<>();
        if (t.equals("tiobe")) {
            list.add(new News("TIOBE:2018年编程语言排行趋势", "2018-5-1", "TIOBE", "..."));
            list.add(new News("TIOBE:2019年编程语言排行趋势", "2019-5-1", "TIOBE", "..."));
            list.add(new News("TIOBE:2020年编程语言排行趋势", "2020-5-1", "TIOBE", "..."));
            list.add(new News("TIOBE:2021年编程语言排行趋势", "2021-5-1", "TIOBE", "..."));
        } else if(t.equals("pypl")){
            list.add(new News("PYPL:2018年编程语言排行趋势", "2018-5-1", "PYPL", "..."));
            list.add(new News("PYPL:2019年编程语言排行趋势", "2019-5-1", "PYPL", "..."));
            list.add(new News("PYPL:2020年编程语言排行趋势", "2020-5-1", "PYPL", "..."));
            list.add(new News("PYPL:2021年编程语言排行趋势", "2021-5-1", "PYPL", "..."));
        }
        ObjectMapper objectMapper = new ObjectMapper();
        String json = objectMapper.writeValueAsString(list);
        response.setContentType("text/json;charset=UTF-8");
        response.getWriter().println(json);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        this.doGet(req, resp);
    }
}