1、缓存(Cache)-工具类

  1. 1、需引入插件依赖
  2.     <dependency>
  3.         <groupId>com.google.guava</groupId>
  4.         <artifactId>guava</artifactId>
  5.         <version>16.0.1</version>
  6.     </dependency>
  7. 2、Demo：
  8.     @Slf4j
  9.     public class CacheUtil {
  10.         public static CacheUtil create() {
  11.             return new CacheUtil();
  12.         }
  14.         public static CacheUtil create(Long number, TimeUnit timeUnit) {
  15.             return new CacheUtil(number, timeUnit);
  16.         }
  18.         private Cache<String, Object> customCache;
  20.         /**
  21.          * 无参构造：缓存过期时间(指定对象被写入到缓存后多久过期),默认为1天.
  22.          * .recordStats(): 开启统计信息开关,统计缓存的命中率
  23.          */
  24.         private CacheUtil() {
  25.             customCache = CacheBuilder.newBuilder()
  26.                 .expireAfterWrite(1L, TimeUnit.HOURS)
  27.                 .recordStats()
  28.                 .removalListener(new RemovalListener<Object, Object>() {
  29.                     @Override
  30.                     public void onRemoval(RemovalNotification<Object, Object> notification) {
  31.                     log.info(notification.getKey() + " was removed, cause is " + notification.getCause());
  32.                     }
  33.                 })
  34.                 .build();
  35.             cleanCache();
  36.         }
  38.         /**
  39.          * 缓存过期时间(指定对象被写入到缓存后多久过期),为传入的单位
  40.          * .recordStats(): 开启统计信息开关,统计缓存的命中率
  41.          * @param timeUnit: 过期时间单位,秒分时日
  42.          */
  43.         private CacheUtil(Long number, TimeUnit timeUnit) {
  44.             //如果传入过期时间数值为空,则默认为1
  45.             if(number == null){
  46.                 number = 1L;
  47.             }
  48.             customCache = CacheBuilder.newBuilder()
  49.                 .expireAfterWrite(number, timeUnit)
  50.                 .recordStats()
  51.                 .removalListener(new RemovalListener<Object, Object>() {
  52.                     @Override
  53.                     public void onRemoval(RemovalNotification<Object, Object> notification) {
  54.                         log.info(notification.getKey() + " was removed, cause is " + notification.getCause());
  55.                     }
  56.                 })
  57.                 .build();
  58.             cleanCache();
  59.         }
  61.         /**
  62.          * 清空缓存
  63.          */
  64.         public void cleanCache() {
  65.             customCache.cleanUp();
  66.         }
  68.         public Object get(String key, Callable<Object> callable) throws ExecutionException {
  69.             return customCache.get(key, callable);
  70.         }
  72.         public Object get(String key) throws ExecutionException {
  73.             return customCache.getIfPresent(key);
  74.         }
  76.         public void put(String key, Object value) throws ExecutionException {
  77.             customCache.put(key, value);
  78.         }
  80.         public static void main(String[] args) throws ExecutionException {
  81.             CacheUtil cacheUtil = CacheUtil.create();
  82.             cacheUtil.put("test",1111);
  83.             Object test = cacheUtil.get("test");
  84.             System.out.println(test.toString());
  85.             cacheUtil.cleanCache();
  86.             System.out.println(cacheUtil.get("test"));
  87.         }
  88.     }