实现 Expiry 接口

public class CaffeineExpiry implements Expiry<String, Object> {
    @Override
    public long expireAfterCreate(@NonNull String key, @NonNull Object value, long currentTime) {
        return 0;
    }

    @Override
    public long expireAfterUpdate(@NonNull String key, @NonNull Object value, long currentTime, @NonNegative long currentDuration) {
        return currentDuration;
    }

    @Override
    public long expireAfterRead(@NonNull String key, @NonNull Object value, long currentTime, @NonNegative long currentDuration) {
        return currentDuration;
    }
}

注意：如果使用常规的 put(key, value) 方法，则需要 expireAfterCreate 方法返回具体的值；下文使用 put(key, value, duration, timeUnit) 方法，expireAfterCreate 方法可以范围任意值，不影响缓存过期时间。

配置

@Configuration
public class CaffeineConfig {
    @Bean
    public Cache<String, Object> caffeineCache() {
        return Caffeine.newBuilder()
                .expireAfter(new CaffeineExpiry())
                .initialCapacity(100)
                .maximumSize(1000)
                .build();
    }
}

使用

@Component
public class CaffeineCacheService {
    @Autowired
    Cache<String, Object> caffeineCache;

    public void set(String key, Object value, long duration, TimeUnit unit) {
        caffeineCache.policy().expireVariably().ifPresent(e->{
            e.put(key, value, duration, unit);
        });
    }

    public <T> T get(String key) {
        return (T)caffeineCache.getIfPresent(key);
    }
}