The technical principles and development of the "DISK LRU CACHE" framework in the Java class library

The "Disk Lru Cache" framework in the Java class library is a tool for caching data on disks. Its technical principles and development actual combats are as follows: Technical principle: 1. Disk cache: DISK LRU CACHE framework uses disk as a cache storage medium. It can save the data on the disk to avoid frequent network requests or complex computing operations. 2. LRU algorithm: This framework manages the cache data based on the LRU (Least Recently Use) algorithm.The LRU algorithm determines which data has been used recently according to the frequency and time of the data, replacing the most commonly used data. 3. Cache index: The framework uses an index table to save the key value pair of the cache data and related metadata. The index table can quickly find and operate the cache data. 4. Writing strategy: When you need to write data to the cache, the framework will use a certain strategy to write the data and update the index table and LRU list. 5. Reading strategy: When reading data, the framework will be found first in the cache. If you find it, return the cache data; if not found, read the data from the disk and write the data into the cache. 6. Thread security: In order to ensure data security in the multi -threaded environment, the framework uses some synchronous mechanisms, such as locks and atomic operations to avoid data competition and inconsistent issues. Development actual combat: The following is an explanation of some example code and related configuration using the Disk Lru Cache framework: 1. Introduction dependencies: First of all, you need to add the DISK LRU Cache framework to the dependence of the project. You can add the following code to the project's built.gradle file: dependencies { implementation 'com.jakewharton:disklrucache:2.0.2' } 2. Initialization cache: In the code, we need to create an instance of Disk Lru Cache and initialize it.You can specify the parameters of the cache path, maximum cache size, and version number by constructing a constructor: String cacheDir = "/path/to/cache/directory"; int maxCacheSize = 10 * 1024 * 1024; // 10MB int appVersion = 1; DiskLruCache cache = DiskLruCache.open(new File(cacheDir), appVersion, 1, maxCacheSize); 3. Write the data: Use the `Editor` object to perform the data writing operation, and set the key value by calling the` set () `method: String key = "my_key"; String value = "my_value"; DiskLruCache.Editor editor = cache.edit(key); editor.set(0, value); editor.commit (); // Submit writing operation 4. Read data: Read the cache data by the `Get ()` method of the cache instance. If you find it, return the data. If not found, return null: String key = "my_key"; DiskLruCache.Snapshot snapshot = cache.get(key); if (snapshot != null) { InputStream inputStream = snapshot.getInputStream(0); // Read data from inputStream } 5. Clear the cache: You can remove the cache data of the specific key by calling the method of calling `delete ()`, or call the `Eviction () method to clear the entire cache: String key = "my_key"; cache.delete (key); // Delete the cache of a specific key cache.evitall (); // Clear the entire cache Summarize: The DISK LRU Cache framework is a Java class library that uses a disk to cache.It uses the LRU algorithm to manage the cache data, providing simple APIs to achieve data read and write operations.Developers can configure relevant configurations according to their own needs and apply them to actual projects to improve data reading performance and reduce resource consumption.