模仿出来的手机版网站 哈哈 高手千万别喷 400 请求报错

$.ajax({
        type : "post",
        url : "${basePath}/servlet/SysUserManageAction?action=register",
        data : params,
        dataType:'text',
        success : function(data)
        {
        	alert(data);
            if (data)
            {
//                 alert("ajax成功!");
//                 var url = $("#save").val();
//                 window.location = url;
            }
            else
            {
//                 alert(json.msg || "ajax失败!");
            }
        },
        error : function(json)
        {
            alert("ajax失败!");
        }
    });

public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String path = request.getContextPath();
		request.setCharacterEncoding("utf-8");
		response.setContentType("text/html; charset=utf-8");
		PrintWriter out = response.getWriter();

		String action = request.getParameter("action");
		if ("register".equals(action)) {
			String flag = service.userRegister(request, response);
			if (flag == null) {
				out.write("注册成功");
			} else {
				out.println("注册失败"); 
			}
		}

		out.flush();
		out.close();
	}