Detailed explanation of the technical principles of the core cache framework in the Java class library

Detailed explanation of the technical principles of the core cache framework in the Java class library Caches is a common and important technology. In the Java class library, many core cache frameworks are available for developers.These frameworks aims to improve the performance and response speed of the application. By storing data in memory, frequent disks or database accesss are avoided. This article will explain some common technical principles of the core cache framework in the Java class library in detail, and provide Java code examples for the situation required. 1. The concept and principle of cache Ccheca is a technology that stores the calculation results in temporary memory so that it can be obtained quickly during subsequent access.It improves the access speed of data by sacrificing part of memory, thereby improving the performance of the application. In Java, there are many benefits to using cache, such as reducing the number of access to databases or other external resources, increasing response speed, and reducing the load of the server. Second, the choice of core cache framework There are many common cache frames in the Java library to choose from, such as EHCACHE, Guava Cache, Caffeine, etc.These frameworks all provide similar functions, but may be somewhat different in implementation. When choosing a cache framework suitable for your own project, you need to consider the following factors: 1. Performance: The cache frame should have efficient reading and writing operations to provide fast data storage and retrieval. 2. Capacity: The cache frame should be able to process a large amount of data to meet the needs in different scenarios. 3. Equipment: Under the multi -threaded environment, the cache frame should be safe and can handle concurrent access. 4. Removal strategy: There should be appropriate mechanisms to remove data that are expired or no longer needed to save memory space. 5. Expansion: The cache frame should have good scalability, which can increase new functions or improve performance according to demand. 3. Technical principle of cache framework 1. Cache strategy: The cache framework usually uses different cache strategies to determine when the data is added and removed.Common cache strategies are: -FIFO (First-in-FIRST-OUT): Advanced first, the earliest adding data will be removed first. -LRU (Least Recently Used): The least recently used data will be removed recently. -LEAST FREQUENTLY Use: The most commonly used, the most unused data will be removed. 2. Causal storage structure: The cache frame usually uses hash tables or orderly sets to store cache data.The hash table provides a fast search function, and the orderly set can sort the data according to the access frequency. 3. Caches preheating: When the application starts, some commonly used data can be loaded into the cache to provide fast access.This process is called cache preheating, which can be loaded into the cache by the application of the application or through the configuration file. 4. Calling hit rate: cache hit rate indicates the proportion of data obtained from the cache.The high hit rate represents the valid cache, while the low -life hit rate indicates that the use of cache needs to be re -considered. Below is a simple example of using the Guava Cache framework: import com.google.common.cache.Cache; import com.google.common.cache.CacheBuilder; public class CacheExample { private static Cache<String, String> cache; public static void main(String[] args) { cache = CacheBuilder.newBuilder() .maximumsize (100) // Set the maximum cache size .build(); // Add data to cache cache.put("key", "value"); // Obtain data from the cache String value = cache.getIfPresent("key"); System.out.println (value); // Output: value // Delete data from the cache cache.invalidate("key"); } } The above example demonstrates how to use Guava Cache to create a simple cache instance and perform data storage, reading and deleting operations. in conclusion Caches is one of the key technologies to improve application performance and response speed.The core cache framework in the Java class library provides flexible and powerful functions, and can choose the appropriate framework according to different needs. This article explains the technical principles of the core cache framework in detail and provides a simple example of using the GUAVA CACHE framework.It is hoped that this article can help readers in -depth understanding of the working principle of the cache framework in the Java class library and use it flexibly in practical applications.