如何在guava(spring)中刷新缓存中的键和值。

removal listener cleanUp

import com.google.common.cache.*;
import org.springframework.stereotype.Component;


import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

@Component
public class Cache {

public static LoadingCache<String, String> REQUIRED_CACHE;

public Cache(){
    RemovalListener<String,String> REMOVAL_LISTENER = new RemovalListener<String, String>() {
        @Override
        public void onRemoval(RemovalNotification<String, String> notification) {
            if(notification.getCause() == RemovalCause.EXPIRED){
                //do as per your requirement
            }
        }
    };

    CacheLoader<String,String> LOADER = new CacheLoader<String, String>() {
        @Override
        public String load(String key) throws Exception {
            return null; // return as per your requirement. if key value is not found
        }
    };

    REQUIRED_CACHE = CacheBuilder.newBuilder().maximumSize(100000000)
            .expireAfterWrite(30, TimeUnit.MINUTES)
            .removalListener(REMOVAL_LISTENER)
            .build(LOADER);

    Executors.newSingleThreadExecutor().submit(()->{
        while (true) {
            REQUIRED_CACHE.cleanUp(); // need to call clean up for removal listener
            TimeUnit.MINUTES.sleep(30L);
        }
    });
}
}

Cache.REQUIRED_CACHE.get("key");
Cache.REQUIRED_CACHE.put("key","value");