In -depth understanding of Spring Cache technology and its application in the Java class library
In -depth understanding of Spring Cache technology and its application in the Java class library
Overview:
In modern software development, cache technology is widely used to improve system performance and response time.The Spring framework provides a convenient cache framework, Spring Cache.This article will explore Spring Cache technology and demonstrate its application in the Java library.
I. What is Spring Cache?
Spring Cache is a statement of a statement cache framework that stored data in memory to avoid repetitive, tedious and expensive database or external service calls, thereby improving system performance and response speed.Spring Cache provides a simple way to define and use the cache, allowing developers to easily integrate the cache with existing applications.
II. Spring Cache working principle:
Spring Cache uses the concept of AOP (Aspect-Oriented Programming) to determine whether to obtain data from the cache by checking the cache before the method execution.If the cache exists, return the cache data directly, otherwise, the method logic is executed and the result is stored in the cache for subsequent use.The Spring Cache framework uses ConcurrenThashMap as a cache storage by default. It can also integrate other cache providers (such as Redis, EHCACHE, etc.).
III. Spring Cache use:
1. Define the cache manager:
In the Spring configuration file, we need to define a cache manager.You can use a simple annotation method @EnableCaching to enable the cache function and configure the cache provider.For example, the configuration of using EHCACHE as a cache provider is as follows:
@Configuration
@EnableCaching
public class CacheConfig {
@Bean
public CacheManager cacheManager() {
EhCacheCacheManager cacheManager = new EhCacheCacheManager();
cacheManager.setCacheManager(ehcacheManager());
return cacheManager;
}
@Bean(destroyMethod = "shutdown")
public net.sf.ehcache.CacheManager ehcacheManager() {
return net.sf.ehcache.CacheManager.newInstance();
}
}
2. Use cache injection solution in the code:
Add caching solutions to the method of cache, such as@cacheable,@cachepput,@cacheevict, etc.Through @Cacheable annotations, Spring Cache will try to obtain data from the cache. If the data exists, it will return directly; if the data does not exist, the method logic will be executed and the result is stored in the cache.For example:
@Service
public class UserService {
@Autowired
private UserRepository userRepository;
@Cacheable(value = "users", key = "#id")
public User getUserById(Long id) {
return userRepository.findById(id);
}
}
3. Clear the cache:
You can use @cacheevict annotations to clear the cache.When a method is executed, you can use @cacheevict annotations to remove one or more caches.For example:
@Service
public class UserService {
@CacheEvict(value = "users", key = "#id")
public void deleteUserById(Long id) {
userRepository.deleteById(id);
}
}
Iv. Spring Cache advantage:
1. Improve performance: Through cache data, the database or external service call is avoided, thereby improving system performance and response speed.
2. Reduce complexity: Spring Cache provides a statement cache configuration, so that developers can easily integrate and use the cache function without paying attention to the details of the bottom layer.
3. Flexibility: Spring Cache supports integrated cache providers. Developers can choose the appropriate cache solution according to actual needs, such as EHCACHE and Redis.
in conclusion:
Spring Cache is a powerful and convenient cache framework. By storing data in memory, the system performance and response speed can be significantly improved.Through the introduction of this article, you should be able to better understand the working principle and usage of Spring Cache, and can apply it to your Java library development.
