很久不写 Servlet 有大佬知道这是啥问题嘛

这是过滤器方法

public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws IOException, ServletException { HttpServletRequest request = (HttpServletRequest)req; HttpServletResponse response = (HttpServletResponse)resp; HttpSession session = request.getSession(); String path = request.getRequestURI(); if(path.contains("login.jsp") || path.contains("/login") ||path.contains("register.jsp") ||path.contains("register") || path.contains("/DrawValidateCode") || path.contains("/layui") || path.contains("/image")){ chain.doFilter(req, resp); //登录页面，登录请求，验证码请求，前端资源和图片一律放行 }else{ String username = (String)session.getAttribute("username"); if (username == null){ //用户不存在一律重定向到登录页 response.sendRedirect(request.getContextPath() + "/login.jsp"); }else { chain.doFilter(req, resp); } } }

这个注册 @WebServlet(urlPatterns = "/addUser") public class RegisterServlet extends HttpServlet {

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    System.out.printf("1111111111111");
}

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    req.setCharacterEncoding("utf-8");
    String jsonRegistration = RequestUtil.getRequestBody(req);
    Gson gson = new Gson();
    JsonObject jsonObject = new JsonParser().parse(jsonRegistration).getAsJsonObject();

    String username = jsonObject.get("username").getAsString();
    String password = jsonObject.get("password").getAsString();

    resp.setContentType("application/json");
    BaseResponse<Integer> baseResponse = new BaseResponse<Integer>();

    boolean registrationSuccess = AdminDao.insertAdministrator(username, password);

    if (registrationSuccess) {
        baseResponse.setCode(200);
        baseResponse.setMsg("注册成功");
        resp.sendRedirect(req.getContextPath() + "/login.jsp");
    } else {
        baseResponse.setCode(500);
        baseResponse.setMsg("注册失败，请重试");
    }

    PrintWriter out = resp.getWriter();
    out.print(gson.toJson(baseResponse));
    out.flush();
    out.close();
}

}

前端就 layui' <script> layui.use(['form'], function(){ var form = layui.form;

    form.on('submit(registrationForm)', function(data){
        var formData = {
            username: data.field.username,
            password: data.field.password
        };
        $.ajax({
            url: '/addUser',
            type: 'POST',
            data: JSON.stringify(formData),
            success: function(res) {
                if(res.code === 200) {
                    layer.msg('注册成功！');
                    window.location.href = '/login.jsp';
                } else {
                    layer.msg('注册失败！');
                }
            },
            error: function(error) {
                layer.msg('注册请求失败：' + error.statusText);
            }
        });

        return false;
    });
});

</script>

就是进不了这个放 addUser 打断也调试了看不出问题