java - Adding an object into a static collection for a static method -

probably stupid question, has been driving me nuts days. first of all, i'm speaking code embedded in larger application class , method signature imposed.

so goal create collection of gc information , code following :

public final class jvmmemstats_svc {     public static final void jvmmemstats(idata pipeline) throws serviceexception {         list<garbagecollectormxbean> gcmbeans = managementfactory.getgarbagecollectormxbeans();         (garbagecollectormxbean gcbean : gcmbeans){ // loop against gcs            gc gc = gcs.get(gcbean.getname());            if( gc != null ){    // gc exists             } else { // new gc                gcs.put(                    gcbean.getname(),                    new gc( gcbean.getcollectioncount(), gcbean.getcollectiontime())                );            }     }      public class gc {         public long cnt, duration;          public gc(long cnt, long duration){             this.set(cnt, duration);         }          public void set(long cnt, long duration){             this.cnt = cnt;             this.duration = duration;         }     }      static map<string, gc> gcindexes = new hashmap<string, gc>(); } 

but got following error @ compilation time :

non-static variable cannot referenced static context :    gcprev.add( new gc( gcbean.getcollectioncount(), gcbean.getcollectiontime()) ); 

well ... i'm lost. tip.

laurent

you're trying create instance of non-static inner class gc inside jvmmemstats() static method.

non-static variable cannot referenced static context :     gcprev.add( new gc( gcbean.getcollectioncount(), gcbean.getcollectiontime()) ); 

the static context being referred above jvmmemstats() method. change class declaration to

public static class gc {      // needs static instantiated in static method }