The technical principles of the Spring Cache framework in the Java class library

The technical principles of the Spring Cache framework in the Java class library Summary: Spring Cache is an annotation -based cache framework that provides a convenient way to achieve a method -level cache for Java developers.This article will introduce the technical principles of the Spring Cache framework, including the underlying implementation principle and working mechanism of the cache.At the same time, we will also use several specific application cases to demonstrate the use of the Spring Cache framework. 1 Introduction With the advent of the era of big data, cache has become one of the important means to improve system performance.In the field of Java development, the Spring Cache framework provides a convenient and flexible way to achieve cache function.By using the Spring Cache framework, we can slow down the return result of the method to improve the performance and response speed of the system. 2. Spring Cache's technical principles The underlying implementation of the Spring Cache framework depends on the standard cache interface provided by Java, such as ConcurrenThashMap.It describes the cache behavior by adding annotations to the method, such as@cacheable,@cacheput, and @cacheevict. 2.1 @cacheable annotation @Cacheable annotation should be cached to describe a return value that describes a method to avoid repeated calculations.It supports multiple cache operations and can specify the cache area used through the value attribute. The following is an example code of @cacheable annotation: @Cacheable(value = "usersCache", key = "#userId") public User getUserById(int userId) { // Actually query the logic of the database } 2.2 @cacheput annotation @CachePut annotation should be cached to describe a method of a method. The difference between it and @cacheable annotation is that@cachePut annotation will force the execution method and cache the return value. The following is a sample code annotated by @cachepput: @CachePut(value = "usersCache", key = "#user.id") public User updateUser(User user) { // The logic of the actual update database return user; } 2.3 @cacheevict annotation @Cacheevict annotations are used to clear one or more data in the cache area after a method execute.It supports many attributes, such as Key, AlLENTRIES, and BeForeinVocation. The following is an example code of @cacheevick annotation: @CacheEvict(value = "usersCache", key = "#userId") public void deleteUser(int userId) { // Realize the data in the database } 3. Application case of Spring Cache Below we will use several specific application cases to demonstrate the use of Spring Cache. 3.1 The return result of the cache method Suppose we have a way to get user information GetUserbyid (int Userid). This method needs to query the database and return the corresponding user object. Using @cacheable annotations, we can add the description of the cache on the method, as shown below: @Cacheable(value = "usersCache", key = "#userId") public User getUserById(int userId) { // Actually query the logic of the database } When the method is called for the first time, the return result of the method will be cached.When calling this method again and passing the same parameters, the method will not be truly executed, but the result of the cache directly returns the cache. 3.2 Update data in the cache If we have a way to update user information, UPDateUser (User User), this method will update the user's information in the database and return the updated user object. Using @cacheput annotations, we can add the description of the cache on the method, as shown below: @CachePut(value = "usersCache", key = "#user.id") public User updateUser(User user) { // The logic of the actual update database return user; } After each call is called, the data in the cache will be updated to the latest results. 3.3 Clear data in the cache If we have a method delete user method deleteuser (int using), this method will delete the corresponding users in the database and clear the corresponding data in the cache. Using @cacheevict annotations, we can add the description of the cache to the method, as shown below: @CacheEvict(value = "usersCache", key = "#userId") public void deleteUser(int userId) { // Realize the data in the database } After each call is called, the data related to the user in the cache will be cleared. 4 Conclusion Through the introduction of the technical principles and application cases of the Spring Cache framework here, we can understand the underlying implementation principles and working mechanisms of Spring Cache.It provides a convenient way to achieve method -level cache to improve the performance and response speed of the system.In practical applications, we can choose the appropriate cache operation annotation according to specific business needs, and use the corresponding cache area to manage the cache data.