<dependency>?
? ? <groupId>net.jodah</groupId>?
? ? <artifactId>expiringmap</artifactId>?
? ? <version>0.5.8</version>?
</dependency>?

public class ExpiringMapApp {

?? ?public static void main(String[] args) {
?? ??? ?// maxSize: 設(shè)置最大值,添加第11個(gè)entry時(shí)，會(huì)導(dǎo)致第1個(gè)立馬過期(即使沒到過期時(shí)間)
?? ??? ?// expiration：設(shè)置每個(gè)key有效時(shí)間10s, 如果key不設(shè)置過期時(shí)間，key永久有效。
?? ??? ?// variableExpiration: 允許更新過期時(shí)間值,如果不設(shè)置variableExpiration，不允許后面更改過期時(shí)間,一旦執(zhí)行更改過期時(shí)間操作會(huì)拋異常UnsupportedOperationException
?? ??? ?// policy:
?? ??? ?// ? ? ? ?CREATED: 只在put和replace方法清零過期時(shí)間
?? ??? ?// ? ? ? ?ACCESSED: 在CREATED策略基礎(chǔ)上增加, 在還沒過期時(shí)get方法清零過期時(shí)間。
?? ??? ?// ? ? ? ?清零過期時(shí)間也就是重置過期時(shí)間，重新計(jì)算過期時(shí)間.
?? ??? ?ExpiringMap<String, String> map = ExpiringMap.builder()
?? ??? ??? ?.maxSize(10)
?? ??? ??? ?.expiration(10, TimeUnit.SECONDS)
?? ??? ??? ?.variableExpiration().expirationPolicy(ExpirationPolicy.CREATED).build();

?? ??? ?map.put("token", "lkj2412lj1412412nmlkjl2n34l23n4");
?? ??? ?map.put("name", "管理員", 20000, TimeUnit.SECONDS);

?? ??? ?// 模擬線程等待...
?? ??? ?try {
?? ??? ??? ?Thread.sleep(15000);
?? ??? ?} catch (InterruptedException e) {
?? ??? ??? ?e.printStackTrace();
?? ??? ?}

?? ??? ?System.out.println("token ===> " + map.get("token"));
?? ??? ?System.out.println("name ===> " + map.get("name"));

?? ??? ?// 注意： 在創(chuàng)建map時(shí)，指定的那些參數(shù)如過期時(shí)間和過期策略都是全局的, 對(duì)map中添加的每一個(gè)entry都適用.
?? ??? ?// ? ? ? ?在put一個(gè)entry鍵值對(duì)時(shí)可以對(duì)當(dāng)前entry 單獨(dú)設(shè)置 過期時(shí)間、過期策略,只對(duì)當(dāng)前這個(gè)entry有效.
?? ?}
}

public class LoadingCacheApp {

?? ?public static void main(String[] args) throws Exception {
?? ??? ?// maximumSize: 緩存池大小，在緩存項(xiàng)接近該大小時(shí)， Guava開始回收舊的緩存項(xiàng)
?? ??? ?// expireAfterAccess: 設(shè)置時(shí)間對(duì)象沒有被讀/寫訪問則對(duì)象從內(nèi)存中刪除(在另外的線程里面不定期維護(hù))
?? ??? ?// removalListener: 移除監(jiān)聽器,緩存項(xiàng)被移除時(shí)會(huì)觸發(fā)的鉤子
?? ??? ?// recordStats: 開啟Guava Cache的統(tǒng)計(jì)功能
?? ??? ?LoadingCache<String, String> cache = CacheBuilder.newBuilder()
?? ??? ??? ?.maximumSize(100)
?? ??? ??? ?.expireAfterAccess(10, TimeUnit.SECONDS)
?? ??? ??? ?.removalListener(new RemovalListener<String, String>() {
?? ??? ??? ??? ?@Override
?? ??? ??? ??? ?public void onRemoval(RemovalNotification<String, String> removalNotification) {
?? ??? ??? ??? ??? ?System.out.println("過時(shí)刪除的鉤子觸發(fā)了... key ===> " + removalNotification.getKey());
?? ??? ??? ??? ?}
?? ??? ??? ?})
?? ??? ??? ?.recordStats()
?? ??? ??? ?.build(new CacheLoader<String, String>() {
?? ??? ??? ??? ?// 處理緩存鍵不存在緩存值時(shí)的處理邏輯
?? ??? ??? ??? ?@Override
?? ??? ??? ??? ?public String load(String key) throws Exception {
?? ??? ??? ??? ??? ?return "不存在的key";
?? ??? ??? ??? ?}
?? ??? ??? ?});

?? ??? ?cache.put("name", "小明");
?? ??? ?cache.put("pwd", "112345");

?? ??? ?// 模擬線程等待...
?? ??? ?try {
?? ??? ??? ?Thread.sleep(15000);
?? ??? ?} catch (InterruptedException e) {
?? ??? ??? ?e.printStackTrace();
?? ??? ?}

?? ??? ?System.out.println("token ===> " + cache.get("name"));
?? ??? ?System.out.println("name ===> " + cache.get("pwd"));
?? ?}
}