策略基于Redis和Java的过期键管理策略（redisjava过期）

Cache expiration is an important aspect of many applications. Without proper expiration settings, the data may become stale or even go stale entirely. To prevent this, we can use the timeout setting in Redis or a custom expiration policy with Java to clear out stale data or enforce useful expiration rules.

To begin with, let’s look at how to configure expiration settings in Redis. Redis offers a variety of timeout settings to help us manage our data, including TTL (Time To Live) and PEXPIRE (Persistent Expiration). With a TTL setting, Redis will delete the stored data after a certain amount of time has passed (measured in seconds). Meanwhile, PEXPIRE will only delete the data if no one else is using it.

Next, let’s turn to Java for a custom expiration policy. We can write a custom expiration policy that checks for expiration time on every put and get operation. If the value has gone stale, the policy will delete it from the cache. We can also configure the expiration policy to add a certain amount of time after each retrieval, meaning the data will remain available until it has been accessed a certain number of times or the age exceeds the specified threshold.

Finally, let’s look at how we can combine Redis with Java to implement a more robust expiration policy. First, we’ll set the TTL in Redis to a shorter expiration period of 10 minutes. This will cause Redis to delete the data if it hasn’t been accessed in 10 minutes. Then, we’ll write a Java policy to delete entries that are older than two hours. This ensures that the data will remain available until it has been accessed two hours, but will be removed if it has expired in the meantime.

Overall, managing cache expiration with Redis and Java can help ensure that our application is always up to date. By setting individual timeouts in Redis and writing custom policies in Java, we can create an intelligent expiration strategy that keeps our data fresh and eliminates stale entries.