春季缓存无法作为计算属性工作

huangapple
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英文:

Spring Cache not working as a compute property

问题

Gradle依赖：

  1. compile 'org.springframework.boot:spring-boot-starter-cache'

Spring Boot应用的主类：

  1. @SpringBootApplication
  2. @EnableCaching
  3. public class Application {
  5.     public static ApplicationContext applicationContext;
  7.     public static void main(String[] args) {
  8.         TimeZone.setDefault(TimeZone.getTimeZone("UTC"));
  9.         // todo: 尝试保存响应文本和请求体
  10.         applicationContext = SpringApplication.run(Application.class, args);
  11.     }
  13.     @Bean
  14.     WebMvcConfigurer webMvcConfigurer(){
  15.         return new WebMvcConfigurer() {
  16.             @Override
  17.             public void addResourceHandlers(ResourceHandlerRegistry registry) {
  18.                 registry
  19.                         .addResourceHandler("/**")
  20.                         .addResourceLocations("classpath:/")
  21.                         .setCacheControl(CacheControl.maxAge(3600, TimeUnit.SECONDS).noTransform().mustRevalidate());
  22.             }
  23.         };
  24.     }
  25. }

我的计算属性和测试方法：

  1. public String test(){
  2.     return hello();
  3. }
  5. @Cacheable("hello")
  6. public String hello(){
  7.     System.out.println("hello");
  8.     return "Hello";
  9. }
英文:

I want to use a mechanism for create a one time compute function. I try to use Spring Caching. But it does not working. Please help me to solve this problem. My code like as below,

Gradle Dependency

  1. compile 'org.springframework.boot:spring-boot-starter-cache'

Main Class of Spring Boot Application

  1. @SpringBootApplication
  2. @EnableCaching
  3. public class Application {
  5. 	public static ApplicationContext applicationContext;
  7. 	public static void main(String[] args) {
  8. 		TimeZone.setDefault(TimeZone.getTimeZone("UTC"));
  9. 		// todo: Try to save response text and request body
  10. 		applicationContext = SpringApplication.run(Application.class, args);
  11. 	}
  13. 	@Bean
  14. 	WebMvcConfigurer webMvcConfigurer(){
  15. 		return new WebMvcConfigurer() {
  16. 			@Override
  17. 			public void addResourceHandlers(ResourceHandlerRegistry registry) {
  18. 				registry
  19. 						.addResourceHandler("/**")
  20. 						.addResourceLocations("classpath:/")
  21. 						.setCacheControl(CacheControl.maxAge(3600, TimeUnit.SECONDS).noTransform().mustRevalidate());
  22. 			}
  23. 		};
  24. 	}
  25. }

My Coputational property and Test method

  1. public String test(){
  2.         return hello();
  3.     }
  6.     @Cacheable("hello")
  7.     public String hello(){
  8.         System.out.println("hello");
  9.         return "Hello";
  10.     }

答案1

得分: 0

@Cacheable注解在从@Bean之外的位置调用时会缓存值，因此从bean内部的另一个方法调用它将不起作用。

尝试类似于以下方式：

  1. @Bean 
  2. public class CachingBean {
  3.     @Cacheable("hello")
  4.     public String hello(){
  5.         System.out.println("hello");
  6.         return "Hello";
  7.     }
  8. }
  10. @Service
  11. public class CallerService {
  13.   @Autowired
  14.   private CachingBean cachingBean;
  16.   // Setters, constructors...
  18.   public String test(){
  19.         return cachingBean.hello();
  20.   }
  21. }

然后它应该会起作用。
这是因为@Cacheable注解在作为Bean注入时会在方法调用周围创建代理，因此直接调用（直接创建的实例）或内部调用不会被拦截，缓存机制甚至不会看到这些调用。

我有时仍会忘记它，并在刚开始时受到影响：)。
干杯！

英文:

The @Cacheable annotation caches the values when it is called from outside your @Bean so calling it from another method inside your bean will not work.

try something like

  1. @Bean 
  2. public class CachingBean {
  3.     @Cacheable("hello")
  4.     public String hello(){
  5.         System.out.println("hello");
  6.         return "Hello";
  7.     }
  8. }
  10. @Service
  11. public class CallerService {
  13.   @Autowired
  14.   private CachingBean cachingBean;
  16.   // Setters, constructors...
  18.   public String test(){
  19.         return cachingBean.hello();
  20.   }
  21. }

And then it should work.
That's because the @Cacheable annotation creates a proxy around the method call when it is injected as a Bean, so a direct call (to an instance created directly) or an internal call are not intercepted and the caching mechanism does not even see those calls.

I still sometimes forget about it and get biten by it at the beginning :).
Cheers!

huangapple
  • 本文由 发表于 2020年4月5日 16:26:51
  • 转载请务必保留本文链接：https://go.coder-hub.com/61039898.html
  • java
  • spring
  • spring-boot
  • spring-cache
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