java - How to perform a Differential Sync between a collection of objects and a DB Table -

i have hashmap of type (string, pojoobj). used java program running , triggered using quartz schedular @ regular intervals.

for safety during abrupt killing of java process.. hashmap destroyed.. making loss of data..

so, planning dump/sync hashmap data ( pojo objects ) when class started executing schedular. effective if sync differential.. ( changed values updated in db ).

i dont have idea it... please me.. using hibernate 3.5 in program.

you can use shutdown handler purpose :

public final class myshutdownhandler extends thread {      private list<iobserver> observerlist;     private static myshutdownhandler shutdownhandler;      private myshutdownhandler() {         observerlist = new arraylist<iobserver>();         runtime.getruntime().addshutdownhook(this);     }      public static myshutdownhandler getshutdownhandler() {         if (shutdownhandler == null) {             synchronized (myshutdownhandler.class) {                 if (shutdownhandler == null) {                     shutdownhandler = new myshutdownhandler();                 }             }         }         return shutdownhandler;     }      public void run() {         (iobserver observer : observerlist) {             observer.execute();         }     }      public void register(iobserver observer) {         observerlist.add(observer);     } } 

you can register many observers (implementations of iobserver) need. particular observer can necessary processes before shutdown happens.

public interface iobserver {      void execute();  }