java - Guava Cacheloader from scratch -

so need store information , reload db every 1 hour. looked around , found googles guava cacheloader or ehcache best , simple solution.

i searched google past 4 hours , didn't find anyhting me, real newbie, first time need cache something. please me out.

follwoing issue:

i have entity called news obisouly store news , load them depending on availibilty. im @viewscoped bean. however, dont need load news every time page loaded, news won't modified freqeuntly. why want store news(list < news>) in cache , load them respectively. cache should refreshed every 1 hour.

please me regarding bean, cache listener etc. have no clue how reload data, have use bean etc.

this @viewscoped newscontroller:

@viewscoped public class newscontroller extends basecontroller implements serializable { private static final long serialversionuid = 1l;  @persistencecontext protected entitymanager em;  private list<news> newslist;  @postconstruct public void init() {     getavailablenews(); }  public void getavailablenews() {     if (newslist == null) {         info("#############load news db!##########");         newslist = new linkedlist<news>();         @suppresswarnings("unchecked")         list<news> result = (list<news>) em.createnativequery(                 "select * news sysdate between , to+1",                 news.class).getresultlist();         (news n : result) {             newslist.add(n);         }     } }  public void reload(){     newslist = null;     getavailablenews(); }  public list<news> getnewslist() {     return newslist; }  public void setnewslist(list<news> newslist) {     this.newslist = newslist; } 

}

have looked @ ehcache spring annotations (http://ehcache.org/documentation/recipes/spring-annotations)? seems that's need here...

simply add @cacheable(name="getavailablenews") above getavailablenews() method, , framework automatically take care of caching results (first time calls db, fetches results back, , cache them...next time, cache directly)

for work though, need change bit class construct...i remove "newslist" instance variable...that's cause inconsistencies , troubles...(you did build sort of home grown "caching" can understand) , update getavailablenews() method return list object...

@cacheable(name="getavailablenews") public list<news> getavailablenews() {     info("#############load news db!##########");     return (list<news>) em.createnativequery(             "select * news sysdate between , to+1",             news.class).getresultlist(); } 

finally, ehcache, can set time expirations on cached entries...hence case, might easy setting timetolive value 1 hour news items...after 1 hour, call db made again...and you'll fetch new "news" values...