高性能内存缓存框架Caffeine，Java

Posted 2022-10-11 zhangphil

高性能内存缓存框架Caffeine，Java

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.https://github.com/ben-manes/caffeine

Caffeine maven库地址：

https://maven-badges.herokuapp.com/maven-central/com.github.ben-manes.caffeine/caffeinehttps://maven-badges.herokuapp.com/maven-central/com.github.ben-manes.caffeine/caffeine