Question

我正在尝试从缓存中获取数据，该缓存存储在本地路径的磁盘中。但是当第一个请求从浏览器发送时，它不会进入缓存，而是通过从数据库中提取数据来覆盖现有缓存（尽管缓存中存在相同的数据）。

如果数据已经存在，如何通过不为每个第一个请求创建新数据来从缓存中获取数据

我正在调用像这样的缓存

public class ServiceListener implements ServletContextListener {
private static final Logger log = Logger.getLogger(ServiceListener.class);
public static CacheManager cm;

public void contextDestroyed(ServletContextEvent arg0) {

}

public void contextInitialized(ServletContextEvent arg0) {
    log.info("initialized");
    // CacheManager c = CacheManager.newInstance();
    cm = CacheManager.getInstance();
}

}

缓存配置

<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="ehcache.xsd" updateCheck="true"
monitoring="autodetect" dynamicConfig="true">
<diskStore path="/home/teja/projects/Main/cacheExp" />
<cache name="cache1" maxEntriesLocalHeap="10000"
    maxEntriesLocalDisk="1000" eternal="true" diskSpoolBufferSizeMB="20"
    timeToIdleSeconds="3000" timeToLiveSeconds="60000"
    diskExpiryThreadIntervalSeconds="150" memoryStoreEvictionPolicy="LFU"
    diskPersistent="true" transactionalMode="off">
    <!-- <persistence strategy="localRestartable" /> -->
</cache></ehcache>

样本用法

String key = width + " " + height;
            if (!cache.isKeyInCache(key)) {
                log.info("entered database");
                List<List> got = support.getDataFromDb(width, height);
                imageList = got.get(0);
                priceList = got.get(1);
                seatList = got.get(2);
                widthList = got.get(3);
                heightList = got.get(4);
                cache.put(new Element(key, got));
            } else {
                log.info("entered cache");
                List got = (List) cache.get(key).getObjectValue();
                imageList = (List<String>) got.get(0);
                priceList = (List<Float>) got.get(1);
                seatList = (List<String>) got.get(2);
                widthList = (List<Integer>) got.get(3);
                heightList = (List<Integer>) got.get(4);
            }

谢谢

应用程序不会从Ehcache获取第一个请求的数据

0 个答案: