/*******************************************************************************
* Copyright (c) 2005, 2014 springside.github.io
*
* Licensed under the Apache License, Version 2.0 (the "License");
*******************************************************************************/
package org.springside.examples.showcase.demos.cache.guava;
import static org.assertj.core.api.Assertions.*;
import java.util.concurrent.TimeUnit;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springside.examples.showcase.entity.User;
import org.springside.examples.showcase.service.AccountService;
import org.springside.modules.test.data.DataFixtures;
import org.springside.modules.test.log.LogbackListAppender;
import org.springside.modules.test.spring.SpringTransactionalTestCase;
import org.springside.modules.utils.Threads;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
/**
* 本地缓存演示，使用GuavaCache.
*
* @author calvin
*/
@ContextConfiguration(locations = { "/applicationContext.xml" })
public class GuavaCacheDemo extends SpringTransactionalTestCase {
@Autowired
private AccountService accountService;
@Test
public void demo() throws Exception {
// 设置缓存最大个数为100，缓存过期时间为5秒
LoadingCache<Long, User> cache = CacheBuilder.newBuilder().maximumSize(100)
.expireAfterAccess(5, TimeUnit.SECONDS).build(new CacheLoader<Long, User>() {
@Override
public User load(Long key) throws Exception {
logger.info("fetch from database");
return accountService.getUser(key);
}
});
// 初始化数据
DataFixtures.executeScript(dataSource, "classpath:data/h2/cleanup-data.sql",
"classpath:data/h2/import-data.sql");
// 插入appender用于assert。
LogbackListAppender appender = new LogbackListAppender();
appender.addToLogger(GuavaCacheDemo.class);
// 第一次加载会查数据库
User user = cache.get(1L);
assertThat(user.getLoginName()).isEqualTo("admin");
assertThat(appender.isEmpty()).isFalse();
appender.clearLogs();
// 第二次加载时直接从缓存里取
User user2 = cache.get(1L);
assertThat(user2.getLoginName()).isEqualTo("admin");
assertThat(appender.isEmpty()).isTrue();
// 第三次加载时，因为缓存已经过期所以会查数据库
Threads.sleep(10, TimeUnit.SECONDS);
User user3 = cache.get(1L);
assertThat(user3.getLoginName()).isEqualTo("admin");
assertThat(appender.isEmpty()).isFalse();
}
}