<dependency>
    <groupId>com.github.ben-manes.caffeine</groupId>
    <artifactId>caffeine</artifactId>
    <version>2.9.2</version>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-cache</artifactId>
</dependency>
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-pool2</artifactId>
    <version>2.8.1</version>
</dependency>

spring:
  redis:
    host: 127.0.0.1
    port: 6379
    database: 0
    timeout: 10000ms
    lettuce:
      pool:
        max-active: 8
        max-wait: -1ms
        max-idle: 8
        min-idle: 0

@Configuration
public class CaffeineConfig {
    @Bean
    public Cache<String,Object> caffeineCache(){
        return Caffeine.newBuilder()
                .initialCapacity(128)//初始大小
                .maximumSize(1024)//最大數(shù)量
                .expireAfterWrite(60, TimeUnit.SECONDS)//過(guò)期時(shí)間
                .build();
    }
}

@Service
@AllArgsConstructor
public class OrderServiceImpl implements OrderService {
    private final OrderMapper orderMapper;

    @Override
    public Order getOrderById(Long id) {  
        Order order = orderMapper.selectOne(new LambdaQueryWrapper<Order>()
              .eq(Order::getId, id));    
        return order;
    }
    
    @Override
    public void updateOrder(Order order) {      
        orderMapper.updateById(order);
    }
    
    @Override
    public void deleteOrder(Long id) {
        orderMapper.deleteById(id);
    }
}

public Order getOrderById(Long id) {
    String key = CacheConstant.ORDER + id;
    Order order = (Order) cache.get(key,
            k -> {
                //先查詢 Redis
                Object obj = redisTemplate.opsForValue().get(k);
                if (Objects.nonNull(obj)) {
                    log.info("get data from redis");
                    return obj;
                }

                // Redis沒(méi)有則查詢 DB
                log.info("get data from database");
                Order myOrder = orderMapper.selectOne(new LambdaQueryWrapper<Order>()
                        .eq(Order::getId, id));
                redisTemplate.opsForValue().set(k, myOrder, 120, TimeUnit.SECONDS);
                return myOrder;
            });
    return order;
}

public void updateOrder(Order order) {
    log.info("update order data");
    String key=CacheConstant.ORDER + order.getId();
    orderMapper.updateById(order);
    //修改 Redis
    redisTemplate.opsForValue().set(key,order,120, TimeUnit.SECONDS);
    // 修改本地緩存
    cache.put(key,order);
}

public void deleteOrder(Long id) {
    log.info("delete order");
    orderMapper.deleteById(id);
    String key= CacheConstant.ORDER + id;
    redisTemplate.delete(key);
    cache.invalidate(key);
}

@Configuration
public class CacheManagerConfig {
    @Bean
    public CacheManager cacheManager(){
        CaffeineCacheManager cacheManager=new CaffeineCacheManager();
        cacheManager.setCaffeine(Caffeine.newBuilder()
                .initialCapacity(128)
                .maximumSize(1024)
                .expireAfterWrite(60, TimeUnit.SECONDS));
        return cacheManager;
    }
}

@Cacheable(value = "order",key = "#id")
//@Cacheable(cacheNames = "order",key = "#p0")
public Order getOrderById(Long id) {
    String key= CacheConstant.ORDER + id;
    //先查詢 Redis
    Object obj = redisTemplate.opsForValue().get(key);
    if (Objects.nonNull(obj)){
        log.info("get data from redis");
        return (Order) obj;
    }
    // Redis沒(méi)有則查詢 DB
    log.info("get data from database");
    Order myOrder = orderMapper.selectOne(new LambdaQueryWrapper<Order>()
            .eq(Order::getId, id));
    redisTemplate.opsForValue().set(key,myOrder,120, TimeUnit.SECONDS);
    return myOrder;
}

#參數(shù)名
#參數(shù)對(duì)象.屬性名
#p參數(shù)對(duì)應(yīng)下標(biāo)

@CachePut(cacheNames = "order",key = "#order.id")
public Order updateOrder(Order order) {
    log.info("update order data");
    orderMapper.updateById(order);
    //修改 Redis
    redisTemplate.opsForValue().set(CacheConstant.ORDER + order.getId(),
            order, 120, TimeUnit.SECONDS);
    return order;
}

@CacheEvict(cacheNames = "order",key = "#id")
public void deleteOrder(Long id) {
    log.info("delete order");
    orderMapper.deleteById(id);
    redisTemplate.delete(CacheConstant.ORDER + id);
}

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface DoubleCache {
    String cacheName();
    String key(); //支持springEl表達(dá)式
    long l2TimeOut() default 120;
    CacheType type() default CacheType.FULL;
}

public enum CacheType {
    FULL,   //存取
    PUT,    //只存
    DELETE  //刪除
}

public static String parse(String elString, TreeMap<String,Object> map){
    elString=String.format("#{%s}",elString);
    //創(chuàng)建表達(dá)式解析器
    ExpressionParser parser = new SpelExpressionParser();
    //通過(guò)evaluationContext.setVariable可以在上下文中設(shè)定變量。
    EvaluationContext context = new StandardEvaluationContext();
    map.entrySet().forEach(entry->
        context.setVariable(entry.getKey(),entry.getValue())
    );

    //解析表達(dá)式
    Expression expression = parser.parseExpression(elString, new TemplateParserContext());
    //使用Expression.getValue()獲取表達(dá)式的值，這里傳入了Evaluation上下文
    String value = expression.getValue(context, String.class);
    return value;
}

public void test() {
    String elString="#order.money";
    String elString2="#user";
    String elString3="#p0";   

    TreeMap<String,Object> map=new TreeMap<>();
    Order order = new Order();
    order.setId(111L);
    order.setMoney(123D);
    map.put("order",order);
    map.put("user","Hydra");

    String val = parse(elString, map);
    String val2 = parse(elString2, map);
    String val3 = parse(elString3, map);

    System.out.println(val);
    System.out.println(val2);
    System.out.println(val3);
}

@Slf4j @Component @Aspect 
@AllArgsConstructor
public class CacheAspect {
    private final Cache cache;
    private final RedisTemplate redisTemplate;

    @Pointcut("@annotation(com.cn.dc.annotation.DoubleCache)")
    public void cacheAspect() {
    }

    @Around("cacheAspect()")
    public Object doAround(ProceedingJoinPoint point) throws Throwable {
        MethodSignature signature = (MethodSignature) point.getSignature();
        Method method = signature.getMethod();

        //拼接解析springEl表達(dá)式的map
        String[] paramNames = signature.getParameterNames();
        Object[] args = point.getArgs();
        TreeMap<String, Object> treeMap = new TreeMap<>();
        for (int i = 0; i < paramNames.length; i++) {
            treeMap.put(paramNames[i],args[i]);
        }

        DoubleCache annotation = method.getAnnotation(DoubleCache.class);
        String elResult = ElParser.parse(annotation.key(), treeMap);
        String realKey = annotation.cacheName() + CacheConstant.COLON + elResult;

        //強(qiáng)制更新
        if (annotation.type()== CacheType.PUT){
            Object object = point.proceed();
            redisTemplate.opsForValue().set(realKey, object,annotation.l2TimeOut(), TimeUnit.SECONDS);
            cache.put(realKey, object);
            return object;
        }
        //刪除
        else if (annotation.type()== CacheType.DELETE){
            redisTemplate.delete(realKey);
            cache.invalidate(realKey);
            return point.proceed();
        }

        //讀寫，查詢Caffeine
        Object caffeineCache = cache.getIfPresent(realKey);
        if (Objects.nonNull(caffeineCache)) {
            log.info("get data from caffeine");
            return caffeineCache;
        }

        //查詢Redis
        Object redisCache = redisTemplate.opsForValue().get(realKey);
        if (Objects.nonNull(redisCache)) {
            log.info("get data from redis");
            cache.put(realKey, redisCache);
            return redisCache;
        }

        log.info("get data from database");
        Object object = point.proceed();
        if (Objects.nonNull(object)){
            //寫入Redis
            redisTemplate.opsForValue().set(realKey, object,annotation.l2TimeOut(), TimeUnit.SECONDS);
            //寫入Caffeine
            cache.put(realKey, object);        
        }
        return object;
    }
}

@DoubleCache(cacheName = "order", key = "#id",
        type = CacheType.FULL)
public Order getOrderById(Long id) {
    Order myOrder = orderMapper.selectOne(new LambdaQueryWrapper<Order>()
            .eq(Order::getId, id));
    return myOrder;
}

@DoubleCache(cacheName = "order",key = "#order.id",
        type = CacheType.PUT)
public Order updateOrder(Order order) {
    orderMapper.updateById(order);
    return order;
}

@DoubleCache(cacheName = "order",key = "#id",
        type = CacheType.DELETE)
public void deleteOrder(Long id) {
    orderMapper.deleteById(id);
}