Spring 的 @EnableCaching 注解
Spring 的 @EnableCaching 注解
cxuan
发布于 2019-06-03 15:17:23
发布于 2019-06-03 15:17:23
@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本文参与 腾讯云自媒体分享计划，分享自微信公众号。
原始发表：2019-03-24，如有侵权请联系 cloudcommunity@tencent.com 删除
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