@EnableCaching注解是spring framework中的注解驱动的缓存管理功能。自spring版本3.1起加入了该注解。如果你使用了这个注解，那么你就不需要在XML文件中配置cache manager了。
当你在配置类(@Configuration)上使用@EnableCaching注解时，会触发一个post processor，这会扫描每一个spring bean，查看是否已经存在注解对应的缓存。如果找到了，就会自动创建一个代理拦截方法调用，使用缓存的bean执行处理。
如果你对缓存感兴趣并想了解更多，请阅读spring caching. 本文会帮助你了解如何使用@EnableCaching注解。
接下来的例子演示了@EnableCaching的用法。在代码中，我缓存了Book类找那个的方法。
importorg.springframework.cache.annotation.Cacheable; public class Book{ @Cacheable(value="simpleCache") public String getBook(int id){ System.out.println("Method cached"); if(id==1){ return "Book 1"; }else{ return "Book 2"; } } } importorg.springframework.cache.CacheManager; importorg.springframework.cache.annotation.EnableCaching; importorg.springframework.cache.concurrent.ConcurrentMapCache; importorg.springframework.cache.support.SimpleCacheManager; importorg.springframework.context.annotation.Bean; importorg.springframework.context.annotation.Configuration; importjava.util.Arrays; @Configuration @EnableCaching public class CachingConfig{ @Bean public Book book(){ return new Book(); } @Bean public CacheManager cacheManager(){ SimpleCacheManager simpleCacheManager = new SimpleCacheManager(); simpleCacheManager.setCaches(Arrays.asList(new ConcurrentMapCache("simpleCache"))); return simpleCacheManager; } } importorg.springframework.context.annotation.AnnotationConfigApplicationContext; public class EnableCachingAnnotationExample{ public static void main(String[] args) { AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(); context.register(CachingConfig.class); context.refresh(); Bookbook=context.getBean(Book.class); System.out.println(book.getBook(1)); System.out.println(book.getBook(1)); System.out.println(book.getBook(2)); context.close(); } }
上面的java config和下面的xml配置文件是等效的：
<beans> <cache:annotation-driven/> <bean id ="book" class = "Book"/> <bean id ="cacheManager" class = "org.springframework.cache.support.SimpleCacheManager"> <property name = "caches"> <set> <bean class = "org.springframework.cache.concurrent.ConcurrentMapCacheFactoryBean"> <property name = "name" value = "sampleCache"/> </bean> </set> </property> </bean> </beans>
测试类
importorg.springframework.context.annotation.AnnotationConfigApplicationContext; public class EnableCachingAnnotationExample{ public static void main(String[] args) { AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext(); ctx.register(CachingConfig.class); ctx.refresh(); Bookbook ctx.getBean(Book.class); // calling getBook method first time. System.out.println(book.getBook(1)); // calling getBook method second time. This time, method will not // execute. System.out.println(book.getBook(1)); // calling getBook method third time with different value. System.out.println(book.getBook(2)); ctx.close(); } }
输出：
Method executed.. Book 1 Book 1 Method executed.. Book 2
