如何创建cookie来标识user_IDs

// 创建cookie
function setCookie(name, value, days) {
  var expires = "";
  if (days) {
    var date = new Date();
    date.setTime(date.getTime() + (days * 24 * 60 * 60 * 1000));
    expires = "; expires=" + date.toUTCString();
  }
  document.cookie = name + "=" + (value || "") + expires + "; path=/";
}

// 获取cookie
function getCookie(name) {
  var nameEQ = name + "=";
  var ca = document.cookie.split(';');
  for (var i = 0; i < ca.length; i++) {
    var c = ca[i];
    while (c.charAt(0) == ' ') c = c.substring(1, c.length);
    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length, c.length);
  }
  return null;
}

// 删除cookie
function eraseCookie(name) {
  document.cookie = name + '=; Max-Age=-99999999;';
}

// 创建cookie
Cookie cookie = new Cookie("user_IDs", "123456");
cookie.setMaxAge(24 * 60 * 60); // 设置cookie的有效期，单位为秒
response.addCookie(cookie);

// 获取cookie
Cookie[] cookies = request.getCookies();
if (cookies != null) {
  for (Cookie cookie : cookies) {
    if (cookie.getName().equals("user_IDs")) {
      String userID = cookie.getValue();
      // 处理userID
      break;
    }
  }
}

// 删除cookie
Cookie cookie = new Cookie("user_IDs", "");
cookie.setMaxAge(0); // 设置cookie的有效期为0，即立即删除
response.addCookie(cookie);