性结合Redis、Java实现多层次的过期性处理（redisjava过期）
Nowadays, data processing technology is being increasingly used in all aspects of our life. With the development of technology, many complex data processing requirements have emerged. Some of the more complicated requirements involve not only the validity of data but also the expiration process. In the distributed environment, when we need to set the expiration of some data, the traditional database technology is not enough. We must use a cache database such as Redis to help with the expiration process. The combination of Java and Redis can effectively solve the multi-level expiration of data in the distributed environment, which will be discussed in detail in this article.
Usually, Redis provides “Expire” command to set the expiration time of data, but when the amount of data is large, we need more detailed control. Redis+Java combination can help us achieve this goal.
The first step is to separate the data from the database into Redis. We can then add the Java expiration management layer on top of Redis. This management layer can be implemented in the form of a timer to periodically refresh the expiration time of data, thus achieving the multi-level expiration of data. Java can query the data in Redis, and process the data that meets the expiration time in a timely manner, and then delete the processed data from the database.
The following is the specific code to realize the abovementioned multi-level expiration. First we initialize the timer, which we will call expiredTimer, and define the setting as:
`Timer expiredTimer = new Timer(1000*60*60,1000*30*60);`
The expiredTimer can run at an interval of one hour and will check the expiration status of the data every thirty minutes. In the run() method of the timer, the query for expired data is:
`connection = redis.getConnection();
// Get the keys that need to be timed out
String sql = “SELECT key from redis_db WHERE expireTime
// Delete these keys
String delKeys = “DELETE FROM redis_db WHERE key in (“+sql+”)”;
connection.execute(delKeys);
`
Finally, we can also use the Redis command to set the expiration time of some data, so that we do not need to write complex code. Here is the code:
`connection = redis.getConnection();
connection.execute(“EXPIRE key 10 seconds”);
`
As we can see, the combination of Java and Redis can help us manage the expiration of distributed data in an efficient and effective manner. With this powerful tool, we can not only set the expiration of data according to the conditions but also adjust the expiration time according to the needs of different data. With the help of this technology, many complex expiration problems can now be solved effectively and easily.
