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Define an exception class in a common package that inherits from RuntimeException. public class BusinessException extends RuntimeException { /** * Abnormal code */ private String code; public BusinessException() { super(); } public BusinessException(String message) { super(message); ...

Concurrent SkipListMap is actually a concurrent version of TreeMap. TreeMap uses red and black trees and is sorted in the order of key s (natural order, custom order), but it is non-thread-safe. In concurrent environments, it is recommended to use Concurrent HashMap or ConcurrentSkipListMap. Concurrent SkipListSet is actually a concurrent vers ...

It took me more than two months. lazzzis Completed the second version of Putong OJ, because in the middle of the busy spring recruitment and graduation design, the project was officially launched recently. Project Online Address: http://acm.cjlu.edu.cn/ Project Front End Address: https://github.com/acm3 ...

Install Redis in a disconnected environment. 1. Reference Articles Ali Cloud Mirror centos7 rpm package download address http://mirrors.aliyun.com/centos/7/os/x86_64/Packages/ Redis download address http://download.redis.io/releases/ https://blog.csdn.net/u010177412/article/details/81780844 https://www.cnblogs.com/yy3b2007com/p/1 ...

I. overview Simply put, a Bloom filter is a way to determine whether an element exists in a list. Usually in JAVA to determine whether there is a Map, Set and other containers. But when the amount of data is very large, using Map and Set will take up too much memory. At this point you'll consider us ...

Problem description The @Cacheable annotation provided by Spring Cache does not support configuring expiration times and automatic refresh of caches. We can configure the default expiration time by configuring CacheManneg and configure the expiration time separately for each cache container (value), but it always feels less flexible. Here is an ...

Grape Command syntax Command Meaning: Set a lifetime for a given key, and when the key expires (lifetime is 0), it will be automatically deleted.Command format: EXPIRE key secondsCommand actual combat: redis> EXPIRE cache_page 30000 # Update expiration time (integer) 1 Return value: Setting successfully returns 1.When the key does not ex ...

When our data is stored in Redis, our key s and value s are serialized to the database through the Serializer provided by Spring.RedisTemplate uses JdkSerializationRedisSerializer by default, StringRedisTemplate uses StringRedisSerializer by default. Spring Data JPA provides us with the following Serializers: GenericToStringSerializer, Jackson2 ...

Catalog Chapter XVI. Primary Knowledge Database I. Database II. Composition of database Classification of databases IV. Unloading database 5. Installation of databases 6. Connecting database 7. Viewing User Information 8. Basic operation of database 9. Basic ope ...

Redis cluster configuration example:1. The difference between relational and non-relational databases: Redis database is a non-relational database, not the same type as oracle, mysql, sql server and other relational databases. NoSQL is the general name of non-relational databases. The mainstream NOSQL databases include redis, MongBD and so on. ...