<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-cache</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>

spring:
  cache:
    cache-names: user
    type: redis
    redis:
      #緩存前綴
      key-prefix: moshangshang_
      #是否啟用緩存統(tǒng)計(jì)信息。
      enable-statistics: false
      #是否允許緩存 null 值。
      cache-null-values: true
      #寫入 Redis 時(shí)是否使用 key prefix。
      use-key-prefix: true

  redis:
    port: 6379
    host: 127.0.0.1
    password: root
    lettuce:
      pool:
        max-active: 20 #連接池最大連接數(shù)（使用負(fù)值表示沒有限制）
        max-idle: 8   #連接池中的最大空閑連接
        min-idle: 5   # 連接池中的最小空閑連接
    timeout: 6000   #連接超時(shí)時(shí)長（毫秒）

java.lang.IllegalArgumentException: Cache 'user' does not allow 'null' values. Avoid storing null via '@Cacheable(unless="#result == null")' or configure RedisCache to allow 'null' via RedisCacheConfiguration.

@SpringBootApplication
@EnableCaching
public class CacheApplication {
    public static void main(String[] args) {
        SpringApplication.run(CacheApplication.class, args);
    }
}

   /**
     * 根據(jù)id查詢用戶信息
     * 生成的key為moshangshang_user::38
     */
    @GetMapping("/query/{id}")
    @Cacheable(cacheNames = "user",key = "#id",unless = "#result == null")
    public User getById(@PathVariable Long id){
        return userService.getById(id);
    }

    @PostMapping("/save")
    @CachePut( key = "#user.id")
    public User updateUser(User user) {
        userService.saveOrUpdate(user);
        return user;
    }

    /**
     * @CacheEvict 在方法執(zhí)行期間拋出異常不會(huì)清空緩存：如果方法執(zhí)行過程中拋出異常，@CacheEvict 的 allEntries 屬性不會(huì)生效。
     * @CacheEvict 用于標(biāo)記方法，表示該方法執(zhí)行時(shí)會(huì)清除緩存中的數(shù)據(jù)。
     * 它可以用于刪除緩存中的所有鍵值對(duì)，也可以用于清除特定的 key。
     * value 或 cacheNames：指定要清除的緩存名稱。
     * key：指定要清除的緩存鍵，可以使用 SpEL 表達(dá)式來定義。
     * allEntries：是否清除所有緩存條目，為 true 時(shí)清除所有緩存。
     * beforeInvocation：是否在方法執(zhí)行前清除緩存，為 true 時(shí)在方法執(zhí)行前清除緩存。
     * condition：指定清除緩存的條件，只有當(dāng)條件為 true 時(shí)，才會(huì)清除緩存。
     */
    @GetMapping("/delete/{id}")
    @CacheEvict(key = "#id", allEntries = false)
    public void deleteUser(@PathVariable Long id) {
        userService.removeById(id);
    }

    @GetMapping("/save/caching")
    @Caching(
            cacheable = @Cacheable( key = "#user.id"),
            put = @CachePut( key = "#user.id"),
            evict = @CacheEvict( key = "#user.id")
    )
    public User saveUser(User user) {
        userService.save(user);
        return user;
    }

/**
 * @CacheConfig 用于在類上設(shè)置公共的緩存配置，避免在每個(gè)方法上重復(fù)配置。
 */
@RestController
@AllArgsConstructor
@RequestMapping("cache")
@CacheConfig(cacheNames = "user")
public class CacheController {

    private final IUserService userService;

 
    @GetMapping("/query/{id}")
    @Cacheable(key = "#id",unless = "#result == null")
    public User getById(@PathVariable Long id){
        return userService.getById(id);
    }
}

@Configuration
public class CacheConfig {

    @Bean(name = "customKeyGenerator")
    public KeyGenerator keyGenerator() {
        return (target, method, params) -> method.getName() + "[" + Arrays.asList(params) + "]";
    }
}

    @Bean(name = "customKeyGenerator")
    public KeyGenerator keyGenerator() {
        return new KeyGenerator() {
            @Override
            public Object generate(Object target, Method method, Object... params) {
                return method.getName() + "[" + Arrays.asList(params) + "]";
            }
        };
    }

    @Cacheable(unless = "#result == null",keyGenerator = "customKeyGenerator")
    public User getById(@PathVariable Long id){
        return userService.getById(id);
    }

@Configuration
public class CacheConfig {
    
    @Bean
    public ConcurrentMapCacheManager mapCacheManager() {
        return new ConcurrentMapCacheManager("user-map","user");
    }
    
}

    /**
     * 執(zhí)行的是mapCacheManager的緩存管理器
     */
    @GetMapping("/manger/map/query/{id}")
    @Cacheable(cacheManager = "mapCacheManager")
    public User getRedisMangerById(@PathVariable Long id){
        return userService.getById(id);
    }

public class CustomCacheResolver implements CacheResolver {
    
    private final ConcurrentMapCacheManager concurrentMapCacheManager;
    
    private final RedisCacheManager redisCacheManager;

    public CustomCacheResolver(ConcurrentMapCacheManager concurrentMapCacheManager, 
                               RedisCacheManager redisCacheManager) {
        this.concurrentMapCacheManager = concurrentMapCacheManager;
        this.redisCacheManager = redisCacheManager;
    }



    @Override
    public Collection<? extends Cache> resolveCaches(CacheOperationInvocationContext<?> context) {
        Collection<Cache> caches = new ArrayList<>();
        if (context.getTarget().getClass() == CacheController.class) {
            if (context.getMethod().getName().equals("getRedisById")) {
                caches.add(redisCacheManager.getCache("user"));
            }else {
                caches.add(concurrentMapCacheManager.getCache("user-map"));
            }
        }
        return caches;
    }
}

    @Bean
    public ConcurrentMapCacheManager mapCacheManager() {
        return new ConcurrentMapCacheManager("user-map","user");
    }


    @Primary
    @Bean
    public RedisCacheManager redisCacheManager(RedisTemplate<String, Object> redisTemplate) {
        return RedisCacheManager.builder(Objects.requireNonNull(redisTemplate.getConnectionFactory()))
                .cacheDefaults(RedisCacheConfiguration.defaultCacheConfig()
                        .entryTtl(Duration.ofMinutes(10)) // 設(shè)置默認(rèn)緩存過期時(shí)間為10分鐘
                        .disableCachingNullValues()) // 禁用緩存空值
                .withInitialCacheConfigurations(initialCacheConfigurations()) // 設(shè)置特定緩存的配置
                .build();
    }

    private Map<String, RedisCacheConfiguration> initialCacheConfigurations() {
        Map<String, RedisCacheConfiguration> initialConfigurations = new HashMap<>();
        // 設(shè)置特定緩存的過期時(shí)間
        initialConfigurations.put("user", RedisCacheConfiguration.defaultCacheConfig()
                .entryTtl(Duration.ofHours(1)) // 設(shè)置特定緩存的過期時(shí)間為1小時(shí)
                .disableCachingNullValues());
        return initialConfigurations;
    }

    @Bean
    public CacheResolver customCacheResolver(ConcurrentMapCacheManager concurrentMapCacheManager,
                                             RedisCacheManager redisCacheManager) {
        return new CustomCacheResolver(concurrentMapCacheManager,redisCacheManager);
    }

  /**
     * 執(zhí)行的是RedisCacheManager的緩存管理器
     */
    @GetMapping("/resolver/redis/query/{id}")
    @Cacheable(unless = "#result == null",cacheResolver = "customCacheResolver")
    public User getRedisById(@PathVariable Long id){
        return userService.getById(id);
    }

    /**
     * 執(zhí)行的是ConcurrentMapCacheManager的緩存管理器
     */
    @GetMapping("/resolver/map/query/{id}")
    @Cacheable(cacheNames = "user-map",unless = "#result == null",cacheResolver = "customCacheResolver")
    public User getMapCacheById(@PathVariable Long id){
        return userService.getById(id);
    }

@Bean
public CacheManagerCustomizer<ConcurrentMapCacheManager> cacheManagerCustomizer() {
    return new CacheManagerCustomizer<ConcurrentMapCacheManager>() {
        @Override
        public void customize(ConcurrentMapCacheManager cacheManager) {
            cacheManager.setCacheNames(Arrays.asList("user"));
            cacheManager.setAllowNullValues(false); // 禁用緩存空值
        }
    };
}


    @Bean
    public RedisCacheManagerBuilderCustomizer redisCacheManagerBuilderCustomizer() {
        return (builder) -> {
            builder.cacheDefaults(
                    RedisCacheConfiguration.defaultCacheConfig()
                            .entryTtl(Duration.ofMinutes(10)) // 默認(rèn)過期時(shí)間為 10 分鐘
                            .disableCachingNullValues()); // 禁用緩存空值
        };
    }