sqlite - insert blob into sqlitedatabase java -

i have created data base , gui collects data user, want add collected data database. connection db good, function called on button click failing, returning message "null pointer exception: null"

system output:

 opened database   add  database  java.lang.nullpointerexception: null 

addtobase:

    private void addtobase(string name, int row) throws exception, ioexception, sqlexception {     preparedstatement st = null;     fileinputstream fis = null;      connection con = null;      try {     class.forname("org.sqlite.jdbc").newinstance();     con = drivermanager.getconnection("jdbc:sqlite:heores.sqlite");     con.setautocommit(false);     system.out.println("opened database successfully");     fileinputstream inputstream= new fileinputstream(selectedfile.getabsolutepath());     string sql = "insert hero (name, row, img) values (?, ?, ?)";     st = con.preparestatement(sql);      st.setstring(1, name);     st.setint(2, row);     st.setblob(3,inputstream);     st.executeupdate();     con.commit();     system.out.println("add  database successfully");     }      catch(exception e) {     system.err.println( e.getclass().getname() + ": " + e.getmessage() );     system.exit(0);     }       {     st.close();     fis.close();       //<--- null here?     }  } 

button action listener:

    private void jbutton2actionperformed(java.awt.event.actionevent evt) {                                              string name;     int row;       switch(row.getselecteditem().tostring()){         case "front":{             row =1;         }         case "middle":{             row =2;         }         case "back":{             row =3;         }         default:{             row=0;         }      }     name=name1.gettext();   //here catches null pointer exeption, addtobase functions seems work fine outputs printed     try {         addtobase(name, row);      } catch ( exception e ) {     system.err.println( e.getclass().getname() + ": " + e.getmessage() );     system.exit(0);     } } 

any ideas whats wrong? after opening database seems columns filled except img column (blob), file i'm inserting declared in main:

public class main extends javax.swing.jframe {  image image; file selectedfile = new file("avatar.png"); //... 

i have checked

if( input!= null){ function(input); } 

but variables , inputs seems initialized

update: ok i've got stack trace

run: opened database add  database java.lang.nullpointerexception: null java.lang.nullpointerexception @ classes.main.addtobase(main.java:82) @ classes.main.jbutton2actionperformed(main.java:304) @ classes.main.access$200(main.java:23) @ classes.main$3.actionperformed(main.java:169) @ javax.swing.abstractbutton.fireactionperformed(abstractbutton.java:2022) @ javax.swing.abstractbutton$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.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) 

 fileinputstream fis = null;  

not set anywhere in code , then:

finally { st.close(); fis.close();       //<--- null here? } 

so fis == null , trying close , exception. pointed there in code comment.