spring.cache.cache-names=foo,bar
spring.cache.caffeine.spec=initialCapacity=10,maximumSize=500,expireAfterAccess=600s

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<dependency>
	<groupId>com.github.ben-manes.caffeine</groupId>
	<artifactId>caffeine</artifactId>
	<version>2.6.2</version>
</dependency>

@Configuration
@EnableCaching //開(kāi)啟緩存
public class CaffeineConfig {
    public static final int DEFAULT_MAXSIZE = 10000;
    public static final int DEFAULT_TTL = 600;
    /**
     * 定義cache名稱(chēng)、超時(shí)時(shí)長(zhǎng)（秒）、最大容量
     * 每個(gè)cache缺?。?0秒超時(shí)、最多緩存50000條數(shù)據(jù)，需要修改可以在構(gòu)造方法的參數(shù)中指定。
     */
    public enum Caches{
        getUserById(600),          //有效期600秒
        listCustomers(7200,1000),  //有效期2個(gè)小時(shí) , 最大容量1000
        ;
        Caches() {
        }
        Caches(int ttl) {
            this.ttl = ttl;
        }
        Caches(int ttl, int maxSize) {
            this.ttl = ttl;
            this.maxSize = maxSize;
        }
        private int maxSize=DEFAULT_MAXSIZE;	//最大數(shù)量
        private int ttl=DEFAULT_TTL;		//過(guò)期時(shí)間（秒）
        public int getMaxSize() {
            return maxSize;
        }
        public int getTtl() {
            return ttl;
        }
    }
    /**
     * 創(chuàng)建基于Caffeine的Cache Manager
     * @return
     */
    @Bean
    @Primary
    public CacheManager caffeineCacheManager() {
        SimpleCacheManager cacheManager = new SimpleCacheManager();
        ArrayList<CaffeineCache> caches = new ArrayList<CaffeineCache>();
        for(Caches c : Caches.values()){
            caches.add(new CaffeineCache(c.name(),
                    Caffeine.newBuilder().recordStats()
                            .expireAfterWrite(c.getTtl(), TimeUnit.SECONDS)
                            .maximumSize(c.getMaxSize())
                            .build())
            );
        }
        cacheManager.setCaches(caches);
        return cacheManager;
    }
}

@RestController
@RequestMapping("cache")
public class CacheController {
    @RequestMapping("listCustomers")
    @Cacheable( value = "listCustomers" , key = "#length", sync = true)
    public List<Customer> listCustomers(Long length){
        List<Customer> customers = new ArrayList<>();
        for(int i=1; i <= length ; i ++){
            Customer customer = new Customer(i, "zhuyu"+i, 20 + i, false);
            customers.add(customer);
        }
        return customers;
    }
    // 以第一個(gè)參數(shù)為key進(jìn)行緩存
    @Cacheable(value="users", key="#p0")
    public Long find(Long id) {
        return id;
    }
    // 以User中的id值為key進(jìn)行緩存
    @Cacheable(value="users", key="#user.id")
    public User find(User user) {
         return user;
    }
    // 以User中的id值為key，且 condition 條件滿足則緩存
    @Cacheable(value="users", key="#user.id", condition="#user.id%2==0")
    public User find(User user) {
       return user;
    }
}

  // allEntries表示是否需要清除緩存中的所有元素。默認(rèn)為false，當(dāng)allEntries為true時(shí)，清除所有的元素
  @CacheEvict(value="user", allEntries=true)
  public void delete(Integer id) {
      System.out.println(id);
  }