Caffeine Cache CRUD

原创转载请注明出处：https://www.cnblogs.com/agilestyle/p/15002781.html

Maven Dependency

...
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.20</version>
</dependency>

<dependency>
    <groupId>com.github.ben-manes.caffeine</groupId>
    <artifactId>caffeine</artifactId>
    <version>2.9.2</version>
</dependency>
...

SRC

package org.fool.cache;

import com.github.benmanes.caffeine.cache.Cache;
import com.github.benmanes.caffeine.cache.Caffeine;
import com.github.benmanes.caffeine.cache.RemovalCause;
import com.github.benmanes.caffeine.cache.RemovalListener;
import lombok.extern.slf4j.Slf4j;
import org.checkerframework.checker.nullness.qual.NonNull;
import org.checkerframework.checker.nullness.qual.Nullable;

import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.TimeUnit;

@Slf4j
public class CaffeineCacheService {
    private static final Cache<String, String> CACHE = Caffeine.newBuilder()
            .maximumSize(100)
            .expireAfterAccess(5, TimeUnit.SECONDS)
            .removalListener(new RemovalListener<String, String>() {
                @Override
                public void onRemoval(@Nullable String key, @Nullable String value, @NonNull RemovalCause removalCause) {
                    log.info("removing cache: {{}:{}}", key, value);
                }
            })
            .build();

    /**
     * 获取缓存值
     */
    public static String get(String key, boolean hasDefaultReturn) {
        try {
            String value = hasDefaultReturn ? CACHE.get(key, v -> "test_" + v) : CACHE.getIfPresent(key);
            log.info("get cache with key: {}, value: {}", key, value);
            return value;
        } catch (Exception e) {
            log.error("get cache data error with key: {}", key, e);
        }
        return null;
    }

    /**
     * 移除缓存
     */
    public static void remove(String key) {
        try {
            log.info("remove cache with key: {}", key);
            CACHE.invalidate(key);
        } catch (Exception e) {
            log.error("remove cache data error with key: {}", key, e);
        }
    }

    /**
     * 清空缓存内数据
     */
    public static void removeAll() {
        log.info("remove all cache");
        CACHE.invalidateAll();
    }

    /**
     * 设置缓存值
     * 注: 若已有该key值，则会先移除(会触发removalListener移除监听器)，再添加
     */
    public static void add(String key, String value) {
        CACHE.put(key, value);
        log.info("add cache with key: {}, value: {}", key, value);
    }

    /**
     * 查看缓存中内容
     */
    public static ConcurrentMap<String, String> getAll() {
        log.info("get all cache: {}", CACHE.asMap());
        return CACHE.asMap();
    }

    public static void main(String[] args) throws Exception {
        add("abc", "abcval");
        get("abc", false);
        add("abc", "xyzval");
        get("abc", false);
        getAll();

        System.out.println("===start sleep===");
        Thread.sleep(10000);
        System.out.println("===end sleep===");
        getAll();

        get("cache1", false);
        get("cache2", true);
        get("cache3", true);
        getAll();

        remove("cache2");
        getAll();

        removeAll();
        getAll();
    }
}

Console Output

Reference

https://www.baeldung.com/java-caching-caffeine

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