NullPointerException

[r035198x]

Change

String wczytane_dane=null;

to

String wczytane_dane="";

[oll3i]

i did System.out.prin tln(file_names[i] )to see if the file names are okey and they are
i also did System.out.prin tln(wczytane_da ne) to see if it concatenates the lines to wczytane_dane it doesnt am i using the right function

as u can see below it does display the lines from file (line imie:Jan)
and i still get NullPointerExce ption

thank u for being there


0file_names[i] :38102044556688 97.txt
java.lang.NullP ointerException
at konta_bankowe.I nterfejs.readFi les(Interfejs.j ava)
at konta_bankowe.I nterfejs.wyswie tlHistorieRachu nkow(Interfejs. java)
at konta_bankowe.I nterfejs.access $1(Interfejs.ja va)
at konta_bankowe.I nterfejs$5.acti onPerformed(Int erfejs.java)
at javax.swing.Abs tractButton.fir eActionPerforme d(Unknown Source)
at javax.swing.Abs tractButton$Han dler.actionPerf ormed(Unknown Source)
at javax.swing.Def aultButtonModel .fireActionPerf ormed(Unknown Source)
at javax.swing.Def aultButtonModel .setPressed(Unk nown Source)wczytane _dane
line imie:Jan
wczytane_dane
line nazwisko:Kowals ki
wczytane_dane
line firma:XYZ
wczytane_dane
line rodzaj konta:brazowe
wczytane_dane
line balance:0.0
wczytane_dane
line null
1file_names[i] :38102056434576 89.txt

at javax.swing.pla f.basic.BasicBu ttonListener.mo useReleased(Unk nown Source)
at java.awt.Compon ent.processMous eEvent(Unknown Source)
at javax.swing.JCo mponent.process MouseEvent(Unkn own Source)
at java.awt.Compon ent.processEven t(Unknown Source)
at java.awt.Contai ner.processEven t(Unknown Source)
at java.awt.Compon ent.dispatchEve ntImpl(Unknown Source)
at java.awt.Contai ner.dispatchEve ntImpl(Unknown Source)
at java.awt.Compon ent.dispatchEve nt(Unknown Source)
at java.awt.Lightw eightDispatcher .retargetMouseE vent(Unknown Source)
at java.awt.Lightw eightDispatcher .processMouseEv ent(Unknown Source)
at java.awt.Lightw eightDispatcher .dispatchEvent( Unknown Source)
at java.awt.Contai ner.dispatchEve ntImpl(Unknown Source)
at java.awt.Window .dispatchEventI mpl(Unknown Source)
at java.awt.Compon ent.dispatchEve nt(Unknown Source)
at java.awt.EventQ ueue.dispatchEv ent(Unknown Source)
at java.awt.EventD ispatchThread.p umpOneEventForF ilters(Unknown Source)
at java.awt.EventD ispatchThread.p umpEventsForFil ter(Unknown Source)
at java.awt.EventD ispatchThread.p umpEventsForHie rarchy(Unknown Source)
at java.awt.EventD ispatchThread.p umpEvents(Unkno wn Source)
at java.awt.EventD ispatchThread.p umpEvents(Unkno wn Source)
at java.awt.EventD ispatchThread.r un(Unknown Source)
2file_names[i] :38102066554422 13.txt
java.lang.NullP ointerException
at konta_bankowe.I nterfejs.readFi les(Interfejs.j ava)
at konta_bankowe.I nterfejs.wyswie tlHistorieRachu nkow(Interfejs. java)
at konta_bankowe.I nterfejs.access $1(Interfejs.ja va)
at konta_bankowe.I nterfejs$5.acti onPerformed(Int erfejs.java)
at javax.swing.Abs tractButton.fir eActionPerforme d(Unknown Source)
at javax.swing.Abs tractButton$Han dler.actionPerf ormed(Unknown Source)
at javax.swing.Def aultButtonModel .fireActionPerf ormed(Unknown Source)
at javax.swing.Def aultButtonModel .setPressed(Unk nown Source)
at javax.swing.pla f.basic.BasicBu ttonListener.mo useReleased(Unk nown Source)
at java.awt.Compon ent.processMous eEvent(Unknown Source)
at javax.swing.JCo mponent.process MouseEvent(Unkn own Source)
at java.awt.Compon ent.processEven t(Unknown Source)
at java.awt.Contai ner.processEven t(Unknown Source)
at java.awt.Compon ent.dispatchEve ntImpl(Unknown Source)
at java.awt.Contai ner.dispatchEve ntImpl(Unknown Source)
at java.awt.Compon ent.dispatchEve nt(Unknown Source)
at java.awt.Lightw eightDispatcher .retargetMouseE vent(Unknown Source)
at java.awt.Lightw eightDispatcher .processMouseEv ent(Unknown Source)
at java.awt.Lightw eightDispatcher .dispatchEvent( Unknown Source)
at java.awt.Contai ner.dispatchEve ntImpl(Unknown Source)
at java.awt.Window .dispatchEventI mpl(Unknown Source)
at java.awt.Compon ent.dispatchEve nt(Unknown Source)
at java.awt.EventQ ueue.dispatchEv ent(Unknown Source)
at java.awt.EventD ispatchThread.p umpOneEventForF ilters(Unknown Source)
at java.awt.EventD ispatchThread.p umpEventsForFil ter(Unknown Source)
at java.awt.EventD ispatchThread.p umpEventsForHie rarchy(Unknown Source)
at java.awt.EventD ispatchThread.p umpEvents(Unkno wn Source)
at java.awt.EventD ispatchThread.p umpEvents(Unkno wn Source)
at java.awt.EventD ispatchThread.r un(Unknown Source)
3file_names[i] :38102079812390 12.txt
java.lang.NullP ointerException
at konta_bankowe.I nterfejs.readFi les(Interfejs.j ava)
at konta_bankowe.I nterfejs.wyswie tlHistorieRachu nkow(Interfejs. java)
at konta_bankowe.I nterfejs.access $1(Interfejs.ja va)
at konta_bankowe.I nterfejs$5.acti onPerformed(Int erfejs.java)
at javax.swing.Abs tractButton.fir eActionPerforme d(Unknown Source)
at javax.swing.Abs tractButton$Han dler.actionPerf ormed(Unknown Source)
at javax.swing.Def aultButtonModel .fireActionPerf ormed(Unknown Source)
at javax.swing.Def aultButtonModel .setPressed(Unk nown Source)
at javax.swing.pla f.basic.BasicBu ttonListener.mo useReleased(Unk nown Source)
at java.awt.Compon ent.processMous eEvent(Unknown Source)
at javax.swing.JCo mponent.process MouseEvent(Unkn own Source)
at java.awt.Compon ent.processEven t(Unknown Source)
at java.awt.Contai ner.processEven t(Unknown Source)
at java.awt.Compon ent.dispatchEve ntImpl(Unknown Source)
at java.awt.Contai ner.dispatchEve ntImpl(Unknown Source)
at java.awt.Compon ent.dispatchEve nt(Unknown Source)
at java.awt.Lightw eightDispatcher .retargetMouseE vent(Unknown Source)
at java.awt.Lightw eightDispatcher .processMouseEv ent(Unknown Source)
at java.awt.Lightw eightDispatcher .dispatchEvent( Unknown Source)
at java.awt.Contai ner.dispatchEve ntImpl(Unknown Source)
at java.awt.Window .dispatchEventI mpl(Unknown Source)
at java.awt.Compon ent.dispatchEve nt(Unknown Source)
at java.awt.EventQ ueue.dispatchEv ent(Unknown Source)
at java.awt.EventD ispatchThread.p umpOneEventForF ilters(Unknown Source)
at java.awt.EventD ispatchThread.p umpEventsForFil ter(Unknown Source)
at java.awt.EventD ispatchThread.p umpEventsForHie rarchy(Unknown Source)
at java.awt.EventD ispatchThread.p umpEvents(Unkno wn Source)
at java.awt.EventD ispatchThread.p umpEvents(Unkno wn Source)
at java.awt.EventD ispatchThread.r un(Unknown Source)
0

[oll3i]

i solved it thank u ;] will see when i go further
thank u for ur answers and assistance