如何通过Java清除缓存对象（内存）
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How to clear cache object (memory) through Java
提问by JavaBits
Code snippet used to allocate cache memory:
用于分配缓存内存的代码片段：
private static Cache cache = CacheManager.getInstance().getCache(CACHE_NAME);
public static HashMap<String, XXX> getxxCodes(int version) {
HashMap<String, XXX> xxCodes = new HashMap<String, XXX>();
try{
Object[] cacheResult = cache.get(Constants.I_XX_CODES_FOR_XXX);
if (Boolean.FALSE.equals(cacheResult[1])) {
cache.put(Constants.I_XX_CODES_FOR_XXX, id.loadXXHashMap(version));
cacheResult = cache.get(Constants.I_XX_CODES_FOR_XXX);
}
if(cacheResult[0]!=null){
xxCodes = (HashMap<String, XXX>)cacheResult[0];
}
}catch(Exception e){
logger.error("Exception occured while loading Data from I10_DRG_XX",e);
}
return xxCodes;
}
Now at some point of time I need to load some other "version" into the cache memory. Here version can be 1, 2, 3 etc. So the cache first holds version 1 data (Hash map). Now when I am passing 2 which is unavailable in cache it needs to load specific data again into cache, but before that it is better to clear version 1 data. Do we have commands like flush to clear specific data?
现在在某个时间点我需要将一些其他“版本”加载到缓存中。这里版本可以是 1、2、3 等。所以缓存首先保存版本 1 数据（哈希映射）。现在，当我传递缓存中不可用的 2 时，它需要再次将特定数据加载到缓存中，但在此之前最好清除版本 1 数据。我们有像flush这样的命令来清除特定数据吗？
I hope I am clear with my question. Thanks for helping.
我希望我的问题很清楚。谢谢你的帮助。
采纳答案by JavaBits
I have used the following code and its working correctly,
我使用了以下代码并且它工作正常，
public void flushCache()
{
cache.flush(cacheKeyName)
}
This will delete the Instance of cache from memory. Thanks for all your help.
这将从内存中删除缓存实例。感谢你的帮助。
回答by Shashank Kadne
This will remove the object from the Cache(Assumption:Weblogic cache)..It sets the Time to Liveto "0"
这将从缓存中删除对象（假设：Weblogic 缓存）。它将生存时间设置为“0”
Cache cache = getCache();
cache.remove(cacheKey);
getCache()can be implemented as follows...
getCache()可以实现如下...
public Cache getCache(){
Cache cache = CacheFactory.getCache(cacheKey);
long ttl=0;
cache.setTtl(ttl);
return cache;
}
