router.get('/getCurrentUserInfo',async ctx=>{
 ctx.cookies.set('userInfo',999);
 ctx.body =  'success';
});

  const str = new Buffer('hello cookie!').toString();
  ctx.cookies.set('userInfo',str);

ctx.cookies.set(u_id,111111,{
expires: new Date(),
maxAge: 1000 * 3600 * 4,
domain: '/',
path: '/',
httpOnly: false,
secure: false,
overWrite: false,
})

// 使用expires
const expiresDate = new Date(Date.now() + 1000 * 3600 * 2);  // 2小時(shí)候后過(guò)期
ctx.cookie.set('u_id':11111,{
expires: expiresDate
});
// 使用maxAge
ctx.cookie.set('u_id':11111,{
expires: new Date(1000 * 3600 * 2);
});

//設(shè)置cookie
const expiresDate = new Date(Date.now() + 1000 * 3600 * 4); // 4小時(shí)候過(guò)期
document.cookie = `userName=張三;path='/';expires=${expiresDate.toGMTString()}`;
//刪除cookie
const expiresDate = new Date(); 
document.cookie = `userName=張三;path='/';expires=${expiresDate.toGMTString()}`;

const kao = require('koa');
const session  = require('koa-session');
const app = new Koa();
const CONFIG = {
  key: 'koa.sess', /** (string) cookie key (default is koa.sess) */
  /** (number || 'session') maxAge in ms (default is 1 days) */
  /** 'session' will result in a cookie that expires when session/browser is closed */
  /** Warning: If a session cookie is stolen, this cookie will never expire */
  maxAge: 1000 * 3600 * 4,
  autoCommit: true, /** (boolean) automatically commit headers (default true) */
  overwrite: true, /** (boolean) can overwrite or not (default true) */
  httpOnly: true, /** (boolean) httpOnly or not (default true) */
  signed: true, /** (boolean) signed or not (default true) */
  rolling: false, /** (boolean) Force a session identifier cookie to be set on every response. The expiration is reset to the original maxAge, resetting the expiration countdown. (default is false) */
  renew: false, /** (boolean) renew session when session is nearly expired, so we can always keep user logged in. (default is false)*/
  secure: false, /** (boolean) secure cookie*/
  sameSite: null, /** (string) session cookie sameSite options (default null, don't set it) */
};
app.use(session(CONFIG, app));
// or if you prefer all default config, just use => app.use(session(app));
app.listen(3000,()=>{});