java - Kotlin Guava Cache 未显示正确的 hitCount

Question

我正在尝试使用 LRU 缓存，如下所示 Java time-based map/cache with expiring keys

我的代码:

import com.google.common.cache.CacheBuilder
import java.util.concurrent.TimeUnit

fun main(args: Array<String>) {


val cache = CacheBuilder.newBuilder().maximumSize(100).
    expireAfterAccess(10, TimeUnit.HOURS)
    .build<String, String>()


    cache.put("a", "blah")
    val x = cache.getIfPresent("a")
    cache.stats().also { println(it) }
    println(x)

}

输出:

CacheStats{hitCount=0, missCount=0, loadSuccessCount=0, loadExceptionCount=0, totalLoadTime=0, evictionCount=0}
blah

我期望 hitCount 为 1，而不是 0。

我在这里缺少什么？

Answer 1

您缺少.recordStats()调用CacheBuilder:

Enable the accumulation of CacheStats during the operation of the cache. Without this Cache.stats() will return zero for all statistics.