Spring Cache缓存条件 使用Spring Cache设置缓存条件操作

@Caching(cacheable=@Cacheable("User"), evict = {@CacheEvict("Member"), @CacheEvict(value = "Customer", allEntries = true)})

//条件缓存
@ResponseBody
@GetMapping("/getLocByDname")
@Cacheable(cacheNames = "dept", key = "#dname", condition = "#dname.length()>3")
public String getLocByDname(@RequestParam("dname") String dname) {//key动态参数
    QueryWrapper<Dept> queryMapper = new QueryWrapper<>();
    queryMapper.eq("dname", dname);
    Dept dept = deptService.getOne(queryMapper);
    return dept.getLoc();
}

@ResponseBody
@GetMapping("/getDeptByDname")
@Cacheable(cacheNames = "dept", key = "#dname", unless = "#result.code != 200")
public Result<Dept> getDeptByDname(@RequestParam("dname") String dname){//key动态参数
    QueryWrapper<Dept> queryMapper = new QueryWrapper<>();
    queryMapper.eq("dname", dname);
    Dept dept = deptService.getOne(queryMapper);
    if (dept == null)
        return ResultUtil.error(120, "dept is null");
    else
        return ResultUtil.success(dept);
}

<dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<dependency>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-aop</artifactId>
</dependency>
<!-- 反射工具类用于手动扫描指定包下的注解，根据defaultCache模块增加ehcache缓存域（非Spring Cache必须）-->
<!-- https://mvnrepository.com/artifact/org.reflections/reflections -->
<dependency>
    <groupId>org.reflections</groupId>
    <artifactId>reflections</artifactId>
    <version>0.9.11</version>
</dependency>

<?xml version="1.0" encoding="UTF-8"?>
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="http://ehcache.org/ehcache.xsd"
         updateCheck="false">
    <!-- 磁盘缓存位置 -->
    <diskStore path="java.io.tmpdir" />
    <!--
        name:缓存名称。
        maxElementsInMemory：缓存最大个数。
        eternal:对象是否永久有效，一但设置了，timeout将不起作用。
        timeToIdleSeconds：设置对象在失效前的允许闲置时间（单位：秒）。仅当eternal=false对象不是永久有效时使用，可选属性，默认值是0，也就是可闲置时间无穷大。
        timeToLiveSeconds：设置对象在失效前允许存活时间（单位：秒）。最大时间介于创建时间和失效时间之间。仅当eternal=false对象不是永久有效时使用，默认是0.，也就是对象存活时间无穷大。
        overflowToDisk：当内存中对象数量达到maxElementsInMemory时，Ehcache将会对象写到磁盘中。
        diskSpoolBufferSizeMB：这个参数设置DiskStore（磁盘缓存）的缓存区大小。默认是30MB。每个Cache都应该有自己的一个缓冲区。
        maxElementsOnDisk：硬盘最大缓存个数。
        diskPersistent：是否缓存虚拟机重启期数据 Whether the disk store persists between restarts of the Virtual Machine. The default value is false.
        diskExpiryThreadIntervalSeconds：磁盘失效线程运行时间间隔，默认是120秒。
        memoryStoreEvictionPolicy：当达到maxElementsInMemory限制时，Ehcache将会根据指定的策略去清理内存。默认策略是LRU（最近最少使用）。你可以设置为FIFO（先进先出）或是LFU（较少使用）。
        clearOnFlush：内存数量最大时是否清除。
    -->
    <!-- 默认缓存 -->
    <defaultCache
            eternal="false"
            maxElementsInMemory="200000"
            overflowToDisk="false"
            diskPersistent="false"
            timeToIdleSeconds="0"
            timeToLiveSeconds="600"
            memoryStoreEvictionPolicy="LRU" />
</ehcache>

@Configuration
@EnableCaching
public class CustomConfiguration {
    /**
     * @see org.springframework.cache.interceptor.SimpleKeyGenerator
     * Generate a key based on the specified parameters.
     */
    public static Object generateKey(Object... params) {
        if (params.length == 0) {
            return SimpleKey.EMPTY;
        }
        if (params.length == 1) {
            Object param = params[0];
            if (param != null && !param.getClass().isArray()) {
                return param;
            }
        }
        return new SimpleKey(params);
    }
/**
 * 若将target作为key的一部分时，CGLIB动态代理可能导致重复缓存
 * 注意：返回的key一定要重写hashCode()和toString()，防止key对象不一致导致的缓存无法命中
 * 例如：ehcache 底层存储net.sf.ehcache.store.chm.SelectableConcurrentHashMap#containsKey
 */
    @Bean
    public KeyGenerator customKeyGenerator(){
        return (target, method, params) -> {
            final Object key = generateKey(params);
            StringBuffer buffer = new StringBuffer();
            buffer.append(method.getName());
            buffer.append("::");
            buffer.append(key.toString());
// 注意一定要转为String,否则ehcache key对象可能不一样，导致缓存无法命中
            return buffer.toString();
        };
    }
    /**
     * redis缓存管理器
     */
    @Bean
    @ConditionalOnBean(RedisConfiguration.class)
    @ConditionalOnProperty(prefix = "spring.cache", name = "type", havingValue = "redis",
            matchIfMissing = false)
    public CacheManager redisCacheManager(RedisConnectionFactory redisConnectionFactory) {
        RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig()
                .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(new StringRedisSerializer()))
                .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(new GenericJackson2JsonRedisSerializer()))
                .entryTtl(Duration.ofMinutes(10));
        return RedisCacheManager
                .builder(RedisCacheWriter.lockingRedisCacheWriter(redisConnectionFactory))
                .cacheDefaults(config).build();
    }
/**
 * ehcache缓存管理器(默认)
 * default XML files {@link net.sf.ehcache.config.ConfigurationFactory#parseConfiguration()}
 */
    @Bean
    @ConditionalOnProperty(prefix = "spring.cache", name = "type", havingValue = "ehcache",
            matchIfMissing = true)
    public CacheManager ehcacheCacheManager() {
        net.sf.ehcache.CacheManager cacheManager = net.sf.ehcache.CacheManager.create();
        /**
         * 包扫描查找指定注解并将cacheNames添加到net.sf.ehcache.CacheManager（单例）
         */
        Reflections reflections = new Reflections("com.example.demo.service", new TypeAnnotationsScanner()
                , new SubTypesScanner(), new MethodAnnotationsScanner());
        Set<Class<?>> classesList = reflections.getTypesAnnotatedWith(CacheConfig.class);
        for (Class<?> aClass : classesList) {
            final CacheConfig config = AnnotationUtils.findAnnotation(aClass, CacheConfig.class);
            if (config.cacheNames() != null && config.cacheNames().length > 0) {
                for (String cacheName : config.cacheNames()) {
                    cacheManager.addCacheIfAbsent(cacheName);
                }
            }
        }
        /**
         * 方法级别的注解 @Caching、@CacheEvict、@Cacheable、@CachePut,结合实际业务场景仅扫描@Cacheable即可
         */
        final Set<Method> methods = reflections.getMethodsAnnotatedWith(Cacheable.class);
        for (Method method : methods) {
            final Cacheable cacheable = AnnotationUtils.findAnnotation(method, Cacheable.class);
            if (cacheable.cacheNames() != null && cacheable.cacheNames().length > 0) {
                for (String cacheName : cacheable.cacheNames()) {
                    cacheManager.addCacheIfAbsent(cacheName);
                }
            }
        }
        EhCacheCacheManager ehCacheCacheManager = new EhCacheCacheManager();
        ehCacheCacheManager.setCacheManager(cacheManager);
        return ehCacheCacheManager;
    }
}

@Component
@CacheConfig(cacheNames = "XXXServiceImpl", keyGenerator = "customKeyGenerator")
public class XXXServiceImpl extends ServiceImpl<XXXMapper, XXXEntity> implements XXXService {
    @CacheEvict(allEntries = true)
    public void evictAllEntries() {}
    @Override
    @Cacheable
    public List<XXXEntity> findById(Long id) {
        return this.baseMapper.selectList(new QueryWrapper<XXXEntity>().lambda()
                .eq(XXXEntity::getId, id));
    }
}