19d97c4253
Previously, if a `@Cacheable` method was accessed with the same key by multiple threads, the underlying method was invoked several times instead of blocking the threads while the value is computed. This scenario typically affects users that enable caching to avoid calling a costly method too often. When said method can be invoked by an arbitrary number of clients on startup, caching has close to no effect. This commit adds a new method on `Cache` that implements the read-through pattern: ``` <T> T get(Object key, Callable<T> valueLoader); ``` If an entry for a given key is not found, the specified `Callable` is invoked to "load" the value and cache it before returning it to the caller. Because the entire operation is managed by the underlying cache provider, it is much more easier to guarantee that the loader (e.g. the annotated method) will be called only once in case of concurrent access. A new `sync` attribute to the `@Cacheable` annotation has been addded. When this flag is enabled, the caching abstraction invokes the new `Cache` method define above. This new mode bring a set of limitations: * It can't be combined with other cache operations * Only one `@Cacheable` operation can be specified * Only one cache is allowed * `condition` and `unless` attribute are not supported The rationale behind those limitations is that the underlying Cache is taking care of the actual caching operation so we can't really apply any SpEL or multiple caches handling there. Issue: SPR-9254
Spring Framework
The Spring Framework provides a comprehensive programming and configuration model for modern Java-based enterprise applications -- on any kind of deployment platform. A key element of Spring is infrastructural support at the application level: Spring focuses on the "plumbing" of enterprise applications so that teams can focus on application-level business logic, without unnecessary ties to specific deployment environments.
The framework also serves as the foundation for Spring Integration, Spring Batch and the rest of the Spring family of projects. Browse the repositories under the Spring organization on GitHub for a full list.
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