刷新令牌与过期时间
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刷新令牌与过期时间 是 CoddyKit 上的免费 Flask Academy 课时。 这是第 4 节课，共 4 节。 你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。 这是 Flask Academy 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Flask Academy 课程共包含 4 节课。
本课时的部分内容尚未翻译，以英文显示。
Why Tokens Expire
A stolen token is dangerous only while it works. Giving every access token a short expiry shrinks that window of risk. ⏳
The exp Claim
Expiry lives in the token's exp claim, a timestamp. Once the clock passes it, the token is rejected no matter what.
Set the Lifetime
Control how long access tokens last with JWT_ACCESS_TOKEN_EXPIRES. A short span like 15 minutes is a sensible default.
from datetime import timedelta
app.config["JWT_ACCESS_TOKEN_EXPIRES"] = timedelta(minutes=15)The Re-Login Problem
Short expiry is safe but annoying if users must type their password every 15 minutes. The refresh token solves exactly this.
Two Tokens, Two Jobs
A short access token calls your API; a long-lived refresh token does nothing but request fresh access tokens.
Issue Both at Login
At login, mint an access token and a refresh token together, then return both to the client.
from flask_jwt_extended import create_refresh_token
rt = create_refresh_token(identity=user.id)A Refresh Endpoint
Add a /refresh route guarded by jwt_required(refresh=True) so only a valid refresh token can reach it.
@app.post("/refresh")
@jwt_required(refresh=True)
def refresh():
...Hand Back a New Access Token
Inside /refresh, read the identity and mint a brand-new access token. The user keeps going without retyping a password. 🔄
new = create_access_token(identity=get_jwt_identity())
return {"access_token": new}Refresh Tokens Live Longer
Set JWT_REFRESH_TOKEN_EXPIRES to days or weeks. It is exposed less often, so a longer life is an acceptable trade.
app.config["JWT_REFRESH_TOKEN_EXPIRES"] = timedelta(days=30)Store the Refresh Token Safely
Because it is powerful, keep the refresh token in secure storage, never in plain JavaScript-readable space, and send it only to /refresh.
Revoking Tokens
To truly log someone out, add a blocklist of token ids the server refuses. This is the one bit of state stateless auth sometimes needs.
Quick Check
Recall the job each token type does.
Recap
Keep access tokens short and pair them with a long-lived refresh token that buys new ones at /refresh. Add a blocklist to revoke. ✅
常见问题解答
「刷新令牌与过期时间」课时是免费的吗？
是的 — 「刷新令牌与过期时间」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Flask Academy 课程的其余内容，请升级到 CoddyKit PRO。 Flask Academy 课程共包含 4 节课。
「刷新令牌与过期时间」这节课中我会学到什么？
无需重新登录即可轮换访问令牌 你通过在浏览器中直接运行的动手代码来练习 Flask Academy，全天候 AI 导师会在你学习这节课的过程中回答你的问题。
学习 Flask Academy 需要有经验吗？
无需任何先前经验。CoddyKit 上的 Flask Academy 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。 这是第 4 节课，共 4 节。
「刷新令牌与过期时间」课时需要多长时间？
大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。
我能在这节 Flask Academy 课中编写并运行代码吗？
能。每节 Flask Academy 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。