java me - codenameone - Storage file doesn't delete -

i've added storage file codenameone application. in event wanna delete specific storage file , recreate old filtered data , new data. doesn't work on deletion.

first create method clear storage file in storagemanager class:

public void cleardata(string pstoragetable){     storage.getinstance().deletestoragefile(pstoragetable); } 

in other class use method this:

// load data of specific storage file // ...  new dbmanager().cleardata(threetrans.db_name);  // write old data filtering of specific id , new data // ... 

here method of write data:

public void write(threetrans ptt){     if(store == null) {         store = storage.getinstance();     }      db_name = "tt";      if(!store.exists(db_name)) {         hashtable dephash = new hashtable();         string k = "1" + ptt.getnumber();         dephash.put(k, ptt.tostring());         store.writeobject(db_name, dephash);     }     else {         hashtable dephash = (hashtable)store.readobject(db_name);          if (!dephash.containsvalue(ptt.getnumber())) {             string k = string.valueof(getlastkeynumber());             dephash.put(k, ptt.tostring());             store.writeobject(db_name, dephash);         }     } } 

at first using method delete storage file:

public void cleardata(string pstoragetable){     if(store == null) {         store = storage.getinstance();     }      (string str : store.listentries()) {         if(str.tolowercase().startswith(pstoragetable)) {            store.deletestoragefile(str);         }     } } 

and after problem method changed this;

public void cleardata(string pstoragetable){     storage.getinstance().deletestoragefile(pstoragetable); } 

i'm assuming didn't invoke close() on output stream or input stream working file , there still lock on file. case such issues.