DAO Setter shows NullPointerException error when setting the BigDecimal value - Java Swing -

i getting following error when set decimal values. please ignore naming convention, sorry being copied legacy application.

error

exception in thread "awt-eventqueue-0" java.lang.nullpointerexception     @ com.shams.mainwindow.btnsaveactionperformed(mainwindow.java:161)     @ com.shams.mainwindow.access$200(mainwindow.java:25)     @ com.shams.mainwindow$3.actionperformed(mainwindow.java:85)     @ javax.swing.abstractbutton.fireactionperformed(abstractbutton.java:2022)     @ javax.swing.abstractbutton$handler.actionperformed(abstractbutton.java:2346)     @ javax.swing.defaultbuttonmodel.fireactionperformed(defaultbuttonmodel.java:402)     @ javax.swing.defaultbuttonmodel.setpressed(defaultbuttonmodel.java:259)     @ javax.swing.plaf.basic.basicbuttonlistener.mousereleased(basicbuttonlistener.java:252)     @ java.awt.awteventmulticaster.mousereleased(awteventmulticaster.java:289)     @ java.awt.component.processmouseevent(component.java:6525)     @ javax.swing.jcomponent.processmouseevent(jcomponent.java:3321)     @ java.awt.component.processevent(component.java:6290)     @ java.awt.container.processevent(container.java:2234)     @ java.awt.component.dispatcheventimpl(component.java:4881)     @ java.awt.container.dispatcheventimpl(container.java:2292)     @ java.awt.component.dispatchevent(component.java:4703)     @ java.awt.lightweightdispatcher.retargetmouseevent(container.java:4898)     @ java.awt.lightweightdispatcher.processmouseevent(container.java:4533)     @ java.awt.lightweightdispatcher.dispatchevent(container.java:4462)     @ java.awt.container.dispatcheventimpl(container.java:2278)     @ java.awt.window.dispatcheventimpl(window.java:2739)     @ java.awt.component.dispatchevent(component.java:4703)     @ java.awt.eventqueue.dispatcheventimpl(eventqueue.java:746)     @ java.awt.eventqueue.access$400(eventqueue.java:97)     @ java.awt.eventqueue$3.run(eventqueue.java:697)     @ java.awt.eventqueue$3.run(eventqueue.java:691)     @ java.security.accesscontroller.doprivileged(native method)     @ java.security.protectiondomain$1.dointersectionprivilege(protectiondomain.java:75)     @ java.security.protectiondomain$1.dointersectionprivilege(protectiondomain.java:86)     @ java.awt.eventqueue$4.run(eventqueue.java:719)     @ java.awt.eventqueue$4.run(eventqueue.java:717)     @ java.security.accesscontroller.doprivileged(native method)     @ java.security.protectiondomain$1.dointersectionprivilege(protectiondomain.java:75)     @ java.awt.eventqueue.dispatchevent(eventqueue.java:716)     @ java.awt.eventdispatchthread.pumponeeventforfilters(eventdispatchthread.java:201)     @ java.awt.eventdispatchthread.pumpeventsforfilter(eventdispatchthread.java:116)     @ java.awt.eventdispatchthread.pumpeventsforhierarchy(eventdispatchthread.java:105)     @ java.awt.eventdispatchthread.pumpevents(eventdispatchthread.java:101)     @ java.awt.eventdispatchthread.pumpevents(eventdispatchthread.java:93)     @ java.awt.eventdispatchthread.run(eventdispatchthread.java:82) 

expensedto

import java.math.bigdecimal; import java.util.date;  // public class expense {     bigdecimal fltamt=bigdecimal.zero;     date dtdate;     category category;     long intexpenseid;      public category getcategory() {         return category;     }      public void setcategory(category category) {         this.category = category;     }      public long getintexpenseid() {         return intexpenseid;     }      public void setintexpenseid(long intexpenseid) {         this.intexpenseid = intexpenseid;     }      public bigdecimal getfltamt() {         return fltamt;     }      public void setfltamt(bigdecimal fltamt) {         this.fltamt = fltamt;     }      public date getdtdate() {         return dtdate;     }      public void setdtdate(date dtdate) {         this.dtdate = dtdate;     } } 

mainwindow

.......

    private void btnsaveactionperformed(java.awt.event.actionevent evt) {                                                 // todo add handling code here:         date selecteddate = (date) datepicker.getmodel().getvalue();         simpledateformat dateformat = new simpledateformat("yyyy-mm-dd");         cbitem selected_item = (cbitem) txtcategory.getselecteditem();  system.out.println(selected_item.getid()); system.out.println(selected_item.getname());          lbl.settext(txtamt.gettext() + "," + txtcategory.getselectedindex() + ","+ dateformat.format(selecteddate));        /* addnewpanel.add(lbl);         addnewpanel.revalidate();         addnewpanel.repaint();*/         bigdecimal vl=new bigdecimal(txtamt.gettext());         system.out.print(bigdecimal.one);         expense.setfltamt(bigdecimal.one);         /*expense.setdtdate(new date(dateformat.format(selecteddate)));         category.setintcatid(selected_item.getid());         expense.setcategory(category);*/     }  

i understand error line of setting bigdecimal, not determine causing issue. when comment line works. copied required(i think) code here. wants full code, can copy too. great...!!

thank you...

edited- mainwindow code fully...

/*  * change license header, choose license headers in project properties.  * change template file, choose tools | templates  * , open template in editor.  */ package com.shams;  import com.shams.dto.category; import com.shams.dto.expense; import com.shams.utils.dbconnection; import java.math.bigdecimal; import java.sql.connection; import java.sql.resultset; import java.sql.statement; import java.text.simpledateformat; import java.util.date; import javax.swing.jlabel; import net.sourceforge.jdatepicker.impl.jdatepanelimpl; import net.sourceforge.jdatepicker.impl.jdatepickerimpl; import net.sourceforge.jdatepicker.impl.utildatemodel; /**  *  * @author shamseer  */ public class mainwindow extends javax.swing.jframe {     expense expense;     category category;     /**      * creates new form mainwindow      */     public mainwindow() {          initcomponents();         initmycomponents();         loaddata();     }      /**      * method called within constructor initialize form.      * warning: not modify code. content of method      * regenerated form editor.      */     @suppresswarnings("unchecked")     // <editor-fold defaultstate="collapsed" desc="generated code">                               private void initcomponents() {          mainpanel = new javax.swing.jpanel();         addnewpanel = new javax.swing.jpanel();         txtcategory = new javax.swing.jcombobox();         txtamt = new javax.swing.jtextfield();         btnsave = new javax.swing.jbutton();         viewpanel = new javax.swing.jpanel();         txtreporttype = new javax.swing.jcombobox();         menubaretapp = new javax.swing.jmenubar();         filemenu = new javax.swing.jmenu();         menuaddnew = new javax.swing.jmenuitem();         viewmenu = new javax.swing.jmenu();         jmenuitem1 = new javax.swing.jmenuitem();          setdefaultcloseoperation(javax.swing.windowconstants.exit_on_close);          mainpanel.setlayout(new java.awt.cardlayout());          txtcategory.seteditable(true);         txtcategory.setautoscrolls(true);         txtcategory.addactionlistener(new java.awt.event.actionlistener() {             public void actionperformed(java.awt.event.actionevent evt) {                 txtcategoryactionperformed(evt);             }         });         txtcategory.addkeylistener(new java.awt.event.keyadapter() {             public void keytyped(java.awt.event.keyevent evt) {                 txtcategorykeytyped(evt);             }         });         addnewpanel.add(txtcategory);          txtamt.setpreferredsize(new java.awt.dimension(50, 25));         addnewpanel.add(txtamt);          btnsave.settext("save");         btnsave.settooltiptext("");         btnsave.addactionlistener(new java.awt.event.actionlistener() {             public void actionperformed(java.awt.event.actionevent evt) {                 btnsaveactionperformed(evt);             }         });         addnewpanel.add(btnsave);          mainpanel.add(addnewpanel, "cardaddnewpanel");          txtreporttype.setmodel(new javax.swing.defaultcomboboxmodel(new string[] { "item 1", "item 2", "item 3", "item 4" }));          javax.swing.grouplayout viewpanellayout = new javax.swing.grouplayout(viewpanel);         viewpanel.setlayout(viewpanellayout);         viewpanellayout.sethorizontalgroup(             viewpanellayout.createparallelgroup(javax.swing.grouplayout.alignment.leading)             .addgroup(viewpanellayout.createsequentialgroup()                 .addgap(20, 20, 20)                 .addcomponent(txtreporttype, javax.swing.grouplayout.preferred_size, 83, javax.swing.grouplayout.preferred_size)                 .addcontainergap(516, short.max_value))         );         viewpanellayout.setverticalgroup(             viewpanellayout.createparallelgroup(javax.swing.grouplayout.alignment.leading)             .addgroup(viewpanellayout.createsequentialgroup()                 .addgap(21, 21, 21)                 .addcomponent(txtreporttype, javax.swing.grouplayout.preferred_size, javax.swing.grouplayout.default_size, javax.swing.grouplayout.preferred_size)                 .addcontainergap(414, short.max_value))         );          mainpanel.add(viewpanel, "cardviewpanel");          getcontentpane().add(mainpanel, java.awt.borderlayout.center);          filemenu.settext("file");          menuaddnew.setaccelerator(javax.swing.keystroke.getkeystroke(java.awt.event.keyevent.vk_n, 0));         menuaddnew.settext("add new");         filemenu.add(menuaddnew);          menubaretapp.add(filemenu);          viewmenu.settext("view");          jmenuitem1.setaccelerator(javax.swing.keystroke.getkeystroke(java.awt.event.keyevent.vk_v, 0));         jmenuitem1.settext("view transactions");         jmenuitem1.settooltiptext("");         viewmenu.add(jmenuitem1);          menubaretapp.add(viewmenu);          setjmenubar(menubaretapp);          pack();     }// </editor-fold>                              private void txtcategoryactionperformed(java.awt.event.actionevent evt) {                                                     // todo add handling code here:     }                                                 private void txtcategorykeytyped(java.awt.event.keyevent evt) {                                              // todo add handling code here:      }                                          private void btnsaveactionperformed(java.awt.event.actionevent evt) {                                                 // todo add handling code here:         date selecteddate = (date) datepicker.getmodel().getvalue();         simpledateformat dateformat = new simpledateformat("yyyy-mm-dd");         cbitem selected_item = (cbitem) txtcategory.getselecteditem();  system.out.println(selected_item.getid()); system.out.println(selected_item.getname());          lbl.settext(txtamt.gettext() + "," + txtcategory.getselectedindex() + ","+ dateformat.format(selecteddate));        /* addnewpanel.add(lbl);         addnewpanel.revalidate();         addnewpanel.repaint();*/         bigdecimal vl=new bigdecimal(txtamt.gettext());         system.out.print(bigdecimal.one);         expense.setfltamt(bigdecimal.one);         /*expense.setdtdate(new date(dateformat.format(selecteddate)));         category.setintcatid(selected_item.getid());         expense.setcategory(category);*/     }                                             /**      * @param args command line arguments      */     public static void main(string args[]) {         /* set nimbus , feel */         //<editor-fold defaultstate="collapsed" desc=" , feel setting code (optional) ">         /* if nimbus (introduced in java se 6) not available, stay default , feel.          * details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html           */         try {             (javax.swing.uimanager.lookandfeelinfo info : javax.swing.uimanager.getinstalledlookandfeels()) {                 if ("nimbus".equals(info.getname())) {                     javax.swing.uimanager.setlookandfeel(info.getclassname());                     break;                 }             }         } catch (classnotfoundexception ex) {             java.util.logging.logger.getlogger(mainwindow.class.getname()).log(java.util.logging.level.severe, null, ex);         } catch (instantiationexception ex) {             java.util.logging.logger.getlogger(mainwindow.class.getname()).log(java.util.logging.level.severe, null, ex);         } catch (illegalaccessexception ex) {             java.util.logging.logger.getlogger(mainwindow.class.getname()).log(java.util.logging.level.severe, null, ex);         } catch (javax.swing.unsupportedlookandfeelexception ex) {             java.util.logging.logger.getlogger(mainwindow.class.getname()).log(java.util.logging.level.severe, null, ex);         }         //</editor-fold>          /* create , display form */         java.awt.eventqueue.invokelater(new runnable() {             public void run() {                 new mainwindow().setvisible(true);             }         });     }      // variables declaration - not modify                          private javax.swing.jpanel addnewpanel;     private javax.swing.jpanel viewpanel;     private javax.swing.jbutton btnsave;     private javax.swing.jmenu filemenu;     private javax.swing.jmenuitem jmenuitem1;     private javax.swing.jpanel mainpanel;     private javax.swing.jmenuitem menuaddnew;     private javax.swing.jmenubar menubaretapp;     private javax.swing.jtextfield txtamt;     private javax.swing.jcombobox txtcategory;     private javax.swing.jcombobox txtreporttype;     private javax.swing.jmenu viewmenu;     // end of variables declaration                         utildatemodel model = new utildatemodel();     jdatepanelimpl datepanel = new jdatepanelimpl(model);     jdatepickerimpl datepicker = new jdatepickerimpl(datepanel);      jlabel lbl=new jlabel("");      @suppresswarnings("unchecked")     private void loaddata() {         //jdatepickerutil datpick = new jdatepickerutil();         //cbitem array=new cbitem[]{"test",9};         //vector vctitem = new vector();         //cbitem[] cbit = null;//=new arraylist<>();         try{             connection conn = new dbconnection().createconnection();             statement stmt = conn.createstatement();             string sql = "select * category";             //list<string> catnames= new arraylist<>();             resultset rs = stmt.executequery(sql);             //int size=0;             while(rs.next()){                 //catnames.add(rs.getstring("strcatname"));                 //cbit=new cbitem[size+1];                 //cbit[size]=new cbitem(rs.getint("intcatid"), rs.getstring("strcatname"));//.addelement( new cbitem(1, "car" ) );                 txtcategory.additem(new cbitem(rs.getint("intcatid"), rs.getstring("strcatname")));                 //size++;             }             //txtcategory.additem(cbit);         }         catch(exception e){             e.printstacktrace();         }      }      private void initmycomponents() {          addnewpanel.add(datepicker);         addnewpanel.revalidate();         addnewpanel.repaint();     } } class cbitem{     int id;     string name;      cbitem(int i, string car) {         this.id=i;         this.name=car;     }      public int getid() {         return id;     }      public void setid(int id) {         this.id = id;     }      public string getname() {         return name;     }      public void setname(string name) {         this.name = name;     }      @override     public string tostring(){         return name+" ("+id+")";     }   } 

you have that:

expense expense; 

variable defined, never set. npe. should not @ least initialize it?

expense expense = new expense();