On the technical principles of the core cache framework in the Java class library

The core cache framework in the Java library refers to the framework that improves system performance by using cache technology.In Java development, the cache framework is widely used to increase the response speed, reduce database load and network delay. The technical principles of the core cache frame include three aspects: cache strategy, cache storage and cache update. 1. cache strategy The cache strategy refers to the rules that determine when the data is stored in the cache and when the data reads the data from the cache.There are several common cache strategies: 1. Recently (LRU): Ckeid replacement according to the frequency of data use, the recent minimum data has been replaced by the cache. 2. Advanced first -out (FIFO): Replace it according to the time order of entering the cache, and the earliest data that enters the cache is replaced. 3. Most of the most often used (LFU): Ckenges replacement according to the frequency of data, and the most commonly used data is replaced. 4. Timing Expired: Set the expiration time of the data during the cache, and the data needs to be loaded again after expiration. Second, cache storage Causal storage refers to where the cache frame is stored where the data is. Common cache storage methods include memory cache, local file system and distributed cache. 1. Memory cache: stored data in the memory of the application. Because the memory read and write speed is fast, it is suitable for scenarios that require higher response speed. 2. Local file system: stored data in the local file system, you can read and write data through the file read and write. 3. Distributed cache: stored data on multiple nodes in distributed environments, and realize read and write data through network communication.Common distributed cache frames include Redis and Memcached. Third, cache update The cache update refers to how to update the data in the cache in time when the data changes to ensure the consistency of the data.The common cache updates are the following: 1. Ccheca failure update: When the data changes, the data in the cache is deleted directly, and the latest data is loaded again when accessing again. 2. Synchronous update: When the data changes, update the data in the cache directly to ensure that the data in the cache is consistent with the data in the database. 3. Asynchronous update: When the data changes, first update the data in the database, and then update the data in the cache.Asynchronous updates can improve system performance and concurrency access capacity. Below is a simple Java code example to demonstrate how to use Spring Boot and EHCACHE to achieve a simple cache function: import org.springframework.cache.annotation.Cacheable; import org.springframework.stereotype.Service; @Service public class ProductService { @Cacheable(value = "products", key = "#id") public Product getProductById(int id) { // Get product information from the database Product product = productDao.getProductById(id); return product; } // Other business methods ... } In the above code, the `@cacheable` annotation is added to the` GetProductbyid` method to cache the return result of the method.When this method is called again, you will first find the cache result from the cache. If you exist, return the cache result directly, otherwise the logic of the method will be executed, and the execution result will be placed in the cache. In summary, the core cache framework in the Java class library can improve the performance and response speed of the system through reasonable cache strategies, choosing appropriate cache storage methods, and correct cache update strategies.Essence