The core technical principles of the cache frame of the Java Class Library

Inquiry of the core technical principles of the cache framework in the Java class library Abstract: With the continuous expansion of computer applications, the demand for high performance and scalability has also increased.Caches is a common solution that improves performance by reducing the number of visits to persistent storage.Caffeine is a cache framework widely used in the Java library. This article will explore the core technical principles of cache cache framework, including cache strategies, storage structure, and concurrency processing mechanisms. introduction: In computer science, cache is a technology that stores the calculation results in high -speed temporary memory so that it can provide faster access speed during subsequent access.The use of cache in the application can significantly improve performance and reduce unnecessary calculations or IO operations.Caffeine is a cache framework widely used in the Java library. It provides a set of powerful and flexible functions that can be configured according to the needs of the application. Cache strategy: The cache cache framework supports a variety of cache strategies, including recently unused (LRU), the most commonly used (LFU), and regular elimination.The core principle of these strategies is to determine whether to discard it by maintaining the frequency of access to the key value pair or the final access time.The LRU strategy eliminates the most recently used entries, while the LFU strategy is eliminated according to the frequency of use.The timing elimination strategy is regularly eliminated by the given time interval based on a given time interval.Developers can choose the appropriate cache strategy based on the application mode of the application to maximize the hit rate. Storage structure: The cache cache framework uses the combination of hash tables and two -way linked lists to store cache bar.The hash table is used to quickly find and access the altosity entry through keys, while the two -way linked list is used to maintain the order of access.The design of this storage structure can ensure the read and write operation of the complexity of the constant time and support fast elimination operations. Concurrent processing mechanism: The cache cache framework uses multi-thread and CAS (Compare-And-SWAP) operation to ensure the consistency and concurrency of the cache.When multiple threads access the same entry at the same time, the framework uses CAS operation to judge the state of the purpose and processes it accordingly according to needs.This concurrent processing mechanism can avoid problems such as updating conflicts and dead locks, while improving the efficiency of concurrent access. Complete programming code and related configuration: The following is a simple example that demonstrates how to use the caching cache framework in Java: import com.github.benmanes.caffeine.cache.Cache; import com.github.benmanes.caffeine.cache.Caffeine; public class CaffeineCacheExample { public static void main(String[] args) { // Create a cache instance Cache<String, String> cache = Caffeine.newBuilder() .maximumSize(100) .build(); // Add cache items cache.put("key1", "value1"); cache.put("key2", "value2"); // Get item from the cache String value1 = cache.getIfPresent("key1"); System.out.println(value1); // Move items from the cache cache.invalidate("key1"); // Empty the cache cache.invalidateAll(); } } In the above example, we first created a cache instance through the method of `Caffeine.newbuilder ()` `Cache <string, String>`.We can also configure other attributes in the `caffeine.newbuilder ()`, such as the maximum cache size and expiration time.Then, we use the `put ()` method to add the key value to the cache.`Getifresent ()` method is used to obtain items from cache and return its corresponding value.`invalidate ()` method is used to remove the specified item from the cache.Finally, we can use the `Invalidateall () method to clear the entire cache. in conclusion: Caffeine cache framework is a high -performance cache solution widely used in the Java library.This article explores the core technical principles of the cache cache framework, including cache strategies, storage structure and concurrency processing mechanism.Understanding these principles will help us better understand and use the caching cache framework and improve our application performance. Please note that the above code example is only used to demonstrate the purpose. In actual use, it may need to be configured and modified according to specific needs.