构建缓存对象时调用recordStats()，指定可以做缓存统计

LoadingCache<String,TradeAccount> tradeAccountCache = CacheBuilder.newBuilder().recordStats()

获取缓存统计结果

CacheStats cacheStats = cache.stats();

示例

package bbejeck.guava.chapter6.cache;import bbejeck.guava.common.model.TradeAccount;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.CacheStats;
import com.google.common.cache.LoadingCache;
import org.junit.Test;import java.util.concurrent.TimeUnit;import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertThat;
import static org.mockito.Mockito.*;/*** User: Bill Bejeck* Date: 7/22/13* Time: 9:55 PM*/
public class CacheStatsTest {private CacheLoader<String, TradeAccount> cacheLoader = mock(CacheLoader.class);@Testpublic void testGetCacheStats() throws Exception {TradeAccount expectedTradeAccount = new TradeAccount.Builder().build();when(cacheLoader.load("223")).thenReturn(expectedTradeAccount);when(cacheLoader.load("000")).thenThrow(new RuntimeException("Bad Value"));LoadingCache<String, TradeAccount> tradeAccountCache = CacheBuilder.newBuilder().maximumSize(5000L).expireAfterAccess(10l, TimeUnit.MILLISECONDS).recordStats().build(cacheLoader);TradeAccount tradeAccount = tradeAccountCache.get("223");assertThat(tradeAccount, is(expectedTradeAccount));TradeAccount tradeAccount1 = tradeAccountCache.get("223");assertThat(tradeAccount1, is(expectedTradeAccount));Thread.sleep(20);TradeAccount tradeAccount2 = tradeAccountCache.get("223");assertThat(tradeAccount2, is(expectedTradeAccount));try{tradeAccountCache.get("000");}catch (RuntimeException e){//Ignore expected}CacheStats stats = tradeAccountCache.stats();assertThat(stats.evictionCount(),is(1l));assertThat(stats.hitCount(),is(1l));assertThat(stats.missCount(),is(3l));assertThat(stats.hitRate(),is((double)1/4));assertThat(stats.loadExceptionCount(),is(1l));assertThat(stats.loadExceptionRate(),is((double)1/3));assertThat(stats.loadSuccessCount(),is(2l));verify(cacheLoader, times(2)).load("223");}
}