SpringBoot Cache

1.pom.xml增加2个依赖
2.application.properties增加配置
3.启动类增加@EnableCaching
4.配置CacheManager
5.打印所有缓存内容

注意：在当前类中调用缓存方法失效

    org.springframework.boot
    spring-boot-starter-cache


    com.github.ben-manes.caffeine
    caffeine
    2.8.8

application.properties

caching.specs.user.timeout=10

@EnableCaching
public class SpringbootApiApplication {}



@Configuration
@ConfigurationProperties(prefix = "caching")
@Data
@Component
public class CacheConfiguration {
    @Data
    public static class CacheSpec {
        private Integer timeout;
        private Integer max = 200;
    }

    private Map specs;

    @Primary
    @Bean("simpleCacheManager")
    public CacheManager cacheManager(Ticker ticker) {
        SimpleCacheManager manager = new SimpleCacheManager();
        new CaffeineCacheManager();
        if (specs != null) {
            List caches =
                    specs.entrySet().stream()
                            .map(entry -> buildCache(entry.getKey(),
                                    entry.getValue(),
                                    ticker))
                            .collect(Collectors.toList());
            manager.setCaches(caches);
        }
        return manager;
    }



    private CaffeineCache buildCache(String name, CacheSpec cacheSpec, Ticker ticker) {
        final Caffeine caffeineBuilder
                = Caffeine.newBuilder()
                .expireAfterWrite(cacheSpec.getTimeout(), TimeUnit.SECONDS)
                .maximumSize(cacheSpec.getMax())
                .ticker(ticker);
        return new CaffeineCache(name, caffeineBuilder.build());
    }


    @Bean
    public Ticker ticker() {
        return Ticker.systemTicker();
    }

}

@Service
public class CacheService {

    // condition: 符合条件缓存
    // unless: 符合条件不缓存
    // @Cacheable(cacheNames = "user", condition = "#name != null")
    // @Cacheable(cacheNames = "user", unless = "#result.name.matches(\"null .*\")")
    // @Cacheable(cacheNames = "user", unless = "#result.id==1")
    // methodName cache
    // method.name cache
    // target com.example.springbootapi.service.CacheService@4db1afb2
    // targetClass class com.example.springbootapi.service.CacheService
    // caches [org.springframework.cache.caffeine.CaffeineCache@7313263b]
    // #caches[0].name 异常
    // caches[0].name user
    // args 3,null
    // #args 异常
    // args[0] 3
    // #args[0] 异常
    // p0 3
    // #p0 3
    // #id 3
    // #name Tom
    // p0 + p1 异常
    // #p0 + #p1 3tom
    // #args[0] + #args[1] 异常
    // #id + "_" + #name 3_null
    @Cacheable(cacheNames = "user", key = "#id + \"_\" + #name")
    public User cache(int id, String name) {
        User user = new User(id, name + " " + LocalDateTime.now().toString());
        return user;
    }

    // 修改缓存
    @CachePut("user")
    public User update(int id, String name) {
        User user = new User(id, name + " " + LocalDateTime.now().toString());
        return user;
    }

    // 清除缓存
    @CacheEvict("user")
    public User delete(int id, String name) {
        User user = new User(id, name + " " + LocalDateTime.now().toString());
        return user;
    }
}


调用

String info = cacheService.cache(id, null).toString();
info += "
" + cacheService.cache(id, "tom").toString();


--------------------------------------------------

// 打印所有缓存
Collection cacheNames = cacheManager.getCacheNames();
cacheNames.forEach(cacheName -> {
    Cache cache = cacheManager.getCache(cacheName);
    Object nativeCache = cache.getNativeCache();
    Field[] fields = nativeCache.getClass().getDeclaredFields();
    for (Field field : fields) {
        field.setAccessible(true);
        try {
            System.out.println(field.getName() + "->" + field.get(nativeCache));
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
    }
});
// 打印所有缓存 end