高性能内存缓存框架Caffeine，Java

╰半橙微兮° 2023-09-27 10:16 53阅读 0赞

代码：

package org.example;
    
    import com.github.benmanes.caffeine.cache.*;
    import org.checkerframework.checker.nullness.qual.Nullable;
    
    import java.util.concurrent.TimeUnit;
    
    public class App {
        public static void main(String[] args) {
            try {
                new App().test();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    
        private void test() {
            LoadingCache<String, Object> cache = Caffeine.newBuilder()
                    .maximumSize(99999) //缓存中存储的最大缓存数量，如果超出就开始根据一定策略删缓存
    
                    //在写入一定时间后删掉缓存
                    .expireAfterWrite(100, TimeUnit.SECONDS)
    
                    //在访问（get）一定时间后删掉缓存
                    .expireAfterAccess(15, TimeUnit.SECONDS)
    
                    //在一定时间后刷新缓存
                    .refreshAfterWrite(30, TimeUnit.SECONDS)
    
                    //也可自定义缓存失效策略
                    /**.expireAfter(new Expiry<Object, Object>() {
                    @Override public long expireAfterCreate(Object o, Object o2, long l) {
                    return 0;
                    }
    
                    @Override public long expireAfterUpdate(Object o, Object o2, long l, @NonNegative long l1) {
                    return 0;
                    }
    
                    @Override public long expireAfterRead(Object o, Object o2, long l, @NonNegative long l1) {
                    return 0;
                    }
                    })
                     */
    
                    //删除缓存监听事件
                    .removalListener(new RemovalListener<Object, Object>() {
                        @Override
                        public void onRemoval(@Nullable Object o, @Nullable Object o2, RemovalCause removalCause) {
                            System.out.println(o + " remove  reason ==> " + removalCause);
                        }
                    })
                    .build(new CacheLoader<String, Object>() {
                        @Override
                        public @Nullable Object load(String s) throws Exception {
                            return "new data load";
                        }
                    });
    
            String NAME = "name";
            cache.put(NAME, "zhangphil");
    
            //获取缓存值，如果为空，返回null
            System.out.println(cache.getIfPresent(NAME).toString());
    
            //使NAME这一条缓存失效。
            cache.invalidate(NAME);
            //cache.invalidateAll(); //使所有缓存失效。
            System.out.println(cache.getIfPresent(NAME) + "");
    
            try {
                Thread.sleep(10);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
        }
    }

输出：

> zhangphil  
> null  
> name remove reason ==> EXPLICIT

Caffeine 开源地址：

[GitHub - ben-manes/caffeine: A high performance caching library for JavaA high performance caching library for Java. Contribute to ben-manes/caffeine development by creating an account on GitHub.![fluidicon.png][]https://github.com/ben-manes/caffeine][GitHub - ben-manes_caffeine_ A high performance caching library for JavaA high performance caching library for Java. Contribute to ben-manes_caffeine development by creating an account on GitHub._fluidicon.png_https_github.com_ben-manes_caffeine]

Caffeine maven库地址：

[https://maven-badges.herokuapp.com/maven-central/com.github.ben-manes.caffeine/caffeine![icon-default.png_t_M85B][]https://maven-badges.herokuapp.com/maven-central/com.github.ben-manes.caffeine/caffeine][https_maven-badges.herokuapp.com_maven-central_com.github.ben-manes.caffeine_caffeine_icon-default.png_t_M85B_https_maven-badges.herokuapp.com_maven-central_com.github.ben-manes.caffeine_caffeine]

[fluidicon.png]: https://github.com/fluidicon.png
[GitHub - ben-manes_caffeine_ A high performance caching library for JavaA high performance caching library for Java. Contribute to ben-manes_caffeine development by creating an account on GitHub._fluidicon.png_https_github.com_ben-manes_caffeine]: https://github.com/ben-manes/caffeine
[icon-default.png_t_M85B]: https://csdnimg.cn/release/blog_editor_html/release2.2.0/ckeditor/plugins/CsdnLink/icons/icon-default.png?t=M85B
[https_maven-badges.herokuapp.com_maven-central_com.github.ben-manes.caffeine_caffeine_icon-default.png_t_M85B_https_maven-badges.herokuapp.com_maven-central_com.github.ben-manes.caffeine_caffeine]: https://maven-badges.herokuapp.com/maven-central/com.github.ben-manes.caffeine/caffeine