1 如何調用方法數據增加緩存 2 @Cacheable(value="MY_CACHE", key="'cache_business_' + #business_id") 3 public ShopCacheData loadShopData(long business_id) throws SQLException{ 4 ... 5 return scd; 6 } 7 8 如何通過調用清空緩存 9 @CacheEvict(value="MY_CACHE", key="'cache_business_' + #business_id") //allEntries=true 10 public void cleanBusinessFromCache(long business_id) throws SQLException { 11 return; 12 } 13 14 上面使用Cacheable注釋的方式，如果在同一個Class中調用則緩存無效。 15 16 如： 17 18 public class ShopManager{ 19 20 @Cacheable(value="MY_CACHE", key="'cache_business_' + #business_id") 21 public ShopCacheData loadShopData(long business_id) throws SQLException{ 22 ... 23 return scd; 24 } 25 26 如何通過調用清空緩存 27 @CacheEvict(value="MY_CACHE", key="'cache_business_' + #business_id") //allEntries=true 28 public void cleanBusinessFromCache(long business_id) throws SQLException { 29 return; 30 } 31 32 33 public void readShop(){ 34 35 ShopCacheData shop = loadShopData(1000); //此處調用每次都會執行方法體，而不會使用相映的緩存 36 37 .... 38 39 } 40 41 } 42 43 44 45 解決辦法:必須在方法中手工寫入對Ehcache操作的代碼才能起到作用 46 47 public class ShopManager{ 48 49 @Cacheable(value="MY_CACHE", key="'cache_business_' + #business_id") 50 public ShopCacheData loadShopData(long business_id) throws SQLException{ 51 ShopCacheData scd = null; 52 ... 53 Element el = null; 54 CacheManager manager = CacheManager.create(); 55 // 通過manager可以生成指定名稱的Cache對象 56 Cache cache = manager.getCache("MY_CACHE"); 57 if(cache.isKeyInCache("cache_business_"+business_id)){ 58 el = cache.get("cache_business_"+business_id); 59 return (ShopCacheData)el.getObjectValue(); 60 } 61 //在緩存中沒有找到對應的key則從數據庫讀取相關信息，並在得到后將結果放入緩存 62 scd = loadShopDatafromDb(business_id); 63 if(scd!=null){ 64 el = new Element("cache_business_"+business_id, scd); 65 cache.put(el); 66 } 67 return scd; 68 } 69 70 @CacheEvict(value="MY_CACHE", key="'cache_business_' + #business_id") //allEntries=true 71 public void cleanBusinessFromCache(long business_id) throws SQLException { 72 CacheManager manager = CacheManager.create(); //通過manager可以生成指定名稱的Cache對象 73 Cache cache = manager.getCache("MY_CACHE"); 74 if(cache.isKeyInCache("cache_business_"+business_id)){ //將指定key的緩存對象從緩存中清除 75 cache.remove("cache_business_"+business_id); 76 } 77 return; 78 } 79 80 81 public void readShop(){ 82 83 ShopCacheData shop = loadShopData(1000); //此時調用緩存將有效 84 85 .... 86 87 } 88 89 }
如何調用方法數據增加緩存
@Cacheable(value="MY_CACHE", key="'cache_business_' + #business_id")
public ShopCacheData loadShopData(long business_id) throws SQLException{
...
return scd;
}
如何通過調用清空緩存
@CacheEvict(value="MY_CACHE", key="'cache_business_' + #business_id") //allEntries=true
public void cleanBusinessFromCache(long business_id) throws SQLException {
return;
}
上面使用Cacheable注釋的方式，只能在Controller中調用使緩存有效，如果在同一個Class中調用則緩存無效。
如：
public class ShopManager{
@Cacheable(value="MY_CACHE", key="'cache_business_' + #business_id")
public ShopCacheData loadShopData(long business_id) throws SQLException{
...
return scd;
}
如何通過調用清空緩存
@CacheEvict(value="MY_CACHE", key="'cache_business_' + #business_id") //allEntries=true
public void cleanBusinessFromCache(long business_id) throws SQLException {
return;
}
public void readShop(){
ShopCacheData shop = loadShopData(1000); //此處調用每次都會執行方法體，而不會使用相映的緩存
....
}
}
解決辦法:必須在方法中手工寫入對Ehcache操作的代碼才能起到作用
public class ShopManager{
@Cacheable(value="MY_CACHE", key="'cache_business_' + #business_id")
public ShopCacheData loadShopData(long business_id) throws SQLException{
ShopCacheData scd = null;
...
Element el = null;
CacheManager manager = CacheManager.create();
// 通過manager可以生成指定名稱的Cache對象
Cache cache = manager.getCache("MY_CACHE");
if(cache.isKeyInCache("cache_business_"+business_id)){
el = cache.get("cache_business_"+business_id);
return (ShopCacheData)el.getObjectValue();
}
//在緩存中沒有找到對應的key則從數據庫讀取相關信息，並在得到后將結果放入緩存
scd = loadShopDatafromDb(business_id);
if(scd!=null){
el = new Element("cache_business_"+business_id, scd);
cache.put(el);
}
return scd;
}
@CacheEvict(value="MY_CACHE", key="'cache_business_' + #business_id") //allEntries=true
public void cleanBusinessFromCache(long business_id) throws SQLException {
CacheManager manager = CacheManager.create(); //通過manager可以生成指定名稱的Cache對象
Cache cache = manager.getCache("MY_CACHE");
if(cache.isKeyInCache("cache_business_"+business_id)){ //將指定key的緩存對象從緩存中清除
cache.remove("cache_business_"+business_id);
}
return;
}
public void readShop(){
ShopCacheData shop = loadShopData(1000); //此時調用緩存將有效
....
}
}