수다닷컴

가능하면 제선으로 끝내고 픈데;;;;;;
널포인터익셉션이 납니다.검색해보니깐 null값을 안넣는방법과 익셉션 try catch 로 막는것인데 . ㅠㅠ

아래는 소스이고
빨간색으로 된부분이 익셉션 발생 부분입니다.
메뉴바랑 버튼이랑 같이 액션리스너를 사용못하는건가요.;; ㅠㅠ

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
public class Report extends Frame implements ActionListener
{
Menu file;
MenuItem _save, _exit;

MenuBar mb;
JTextField glas;
JLabel hac;
JTextField sem;
JLabel hacn;
JLabel label1;

JLabel rhk1;
JTextField rhkahr1;
JLabel wja1;
JTextField wjatn1;
JTextField avr;

JLabel rhk2;
JLabel wja2;
JTextField rhkahr2;
JTextField wjatn2;

JLabel rhk3;
JLabel wja3;
JTextField rhkahr3;
JTextField wjatn3;

JLabel rhk4;
JLabel wja4;
JTextField rhkahr4;
JTextField wjatn4;

JLabel rhk5;
JLabel wja5;
JTextField rhkahr5;
JTextField wjatn5;

JLabel rhk6;
JLabel wja6;
JTextField rhkahr6;
JTextField wjatn6;

JLabel rhk7;
JLabel wja7;
JTextField rhkahr7;
JTextField wjatn7;

JLabel rhk8;
JLabel wja8;
JTextField rhkahr8;
JTextField wjatn8;

JLabel rhk9;
JLabel wja9;
JTextField rhkahr9;
JTextField wjatn9;

JLabel rhk10;
JLabel wja10;
JTextField rhkahr10;
JTextField wjatn10 ;

JLabel label2 ;

JTextField avrd;
JLabel label3;
JTextField max;
JLabel label4;
JTextField min;

JButton ok;
JButton save;

public Report(String title)
{
super(title);

file = new Menu(파일);

_save = new MenuItem(저장);
_exit = new MenuItem(종료);

file.add(_save);
file.addSeparator();
file.add(_exit);

mb = new MenuBar();

mb.add(file);
setMenuBar(mb);

_save.addActionListener(this);
_exit.addActionListener(this);

ok.addActionListener(this);
save.addActionListener(this);

//Layout field
GridLayout layout1 = new GridLayout(10,5,5,5);
this.setLayout(layout1);

glas = new JTextField();
hac = new JLabel(학년);
sem = new JTextField();
hacn = new JLabel(학기);
label1 = new JLabel(평균점수);

rhk1 = new JLabel(과목);
rhkahr1 = new JTextField();
wja1 = new JLabel(점수);
wjatn1= new JTextField();
avr = new JTextField();

rhk2 = new JLabel(과목);
wja2= new JLabel(점수);
rhkahr2 = new JTextField();
wjatn2= new JTextField();

rhk3 = new JLabel(과목);
wja3 = new JLabel(점수);
rhkahr3 = new JTextField();
wjatn3= new JTextField();

rhk4 = new JLabel(과목);
wja4 = new JLabel(점수);
rhkahr4 = new JTextField();
wjatn4= new JTextField();

rhk5 = new JLabel(과목);
wja5 = new JLabel(점수);
rhkahr5 = new JTextField();
wjatn5= new JTextField();

rhk6 = new JLabel(과목);
wja6 = new JLabel(점수);
rhkahr6 = new JTextField();
wjatn6= new JTextField();

rhk7 = new JLabel(과목);
wja7 = new JLabel(점수);
rhkahr7 = new JTextField();
wjatn7= new JTextField();

rhk8 = new JLabel(과목);
wja8 = new JLabel(점수);
rhkahr8 = new JTextField();
wjatn8= new JTextField();

rhk9 = new JLabel(과목);
wja9 = new JLabel(점수);
rhkahr9 = new JTextField();
wjatn9= new JTextField();

rhk10 = new JLabel(과목);
wja10 = new JLabel(점수);
rhkahr10 = new JTextField();
wjatn10 = new JTextField();

label2 = new JLabel(평균학점);

avrd= new JTextField();
label3 = new JLabel(점수최대);
max= new JTextField();
label4 = new JLabel(점수최소);
min= new JTextField();

ok = new JButton(확인);
save = new JButton(저장);

add(glas);
add(hac);
add(sem);
add(hacn);
add(label1);

add(rhk1);
add(rhkahr2);
add(wja1);
add(wjatn2);
add(avr);

add(rhk2);
add(rhkahr3);
add(wja2);
add(wjatn3);
add(label2);

add(rhk3);
add(rhkahr4);
add(wja3);d(wja3);
add(wjatn4);
add(avrd);

add(rhk4);
add(rhkahr5);
add(wja4);
add(wjatn5);
add(label3);

add(rhk5);
add(rhkahr6);
add(wja5);
add(wjatn6);
add(max);

add(rhk6);
add(rhkahr7);
add(wja6);
add(wjatn7);
add(label4);

add(rhk7);
add(rhkahr8);
add(wja7);
add(wjatn8);
add(min);

add(rhk8);
add(rhkahr9);
add(wja8);
add(wjatn9);
add(ok);

add(rhk9);
add(rhkahr10);
add(wja9);
add(wjatn10);
add(save);
}

void saveFile()
{
try
{
FileWriter fw = new FileWriter(save.txt,true);
BufferedWriter bf = new BufferedWriter(fw);

bf.write(***************************);
bf.newLine();
bf.write(*　학 점 관 리 프 로 그 램*);
bf.newLine();
bf.write(* + glas.getText() + 학년 +sem.getText() + 학기+ *);
bf.newLine();
bf.write(***************************);
bf.newLine();
bf.write(rhkahr1.getText() + + wjatn1.getText());
bf.newLine();
bf.write(rhkahr2.getText() + + wjatn2.getText());
bf.newLine();
bf.write(rhkahr3.getText() + + wjatn3.getText());
bf.newLine();
bf.write(rhkahr4.getText() + + wjatn4.getText());
bf.newLine();
bf.write(rhkahr5.getText() + + wjatn5.getText());
bf.newLine();
bf.write(rhkahr6.getText() + + wjatn6.getText());
bf.newLine();
bf.write(rhkahr7.getText() + + wjatn7.getText());
bf.newLine();
bf.write(rhkahr8.getText() + + wjatn8.getText());
bf.newLine();
bf.write(rhkahr9.getText() + + wjatn9.getText());
bf.newLine();
bf.write(***************************);
bf.newLine();
bf.write(최대값 + max.getText());
bf.newLine();
bf.write(최소값 + min.getText());
bf.newLine();
bf.write(평균학점 + avr.getText());
bf.newLine();
bf.write(***************************);
bf.newLine();
bf.newLine();

bf.close();

FileReader fr=new FileReader(save.txt);
BufferedReader br=new BufferedReader(fr);
String str=null;

while((str=br.readLine())!=null){
System.out.println(str);
}

br.close();
}
catch(Exception n)
{
System.out.println(n);
}
}

public static void main(String[] args)
{

Report mw = new Report(학점 관리 프로그램);

mw.pack();
mw.setResizable(false);
mw.setVisible(true);

//Close
WindowListener wl = new WindowAdapter()
{
public void windowClosing(WindowEvent we)
{
((Frame)we.getSource()).setVisible(false);
((Frame)we.getSource()).dispose();
System.exit(0);
}
};
mw.addWindowListener(wl);
}
public void actionPerformed(ActionEvent e)
{
String cmd = e.getActionCommand();
if(cmd.equals(저장))
{
saveFile();
}

else if(cmd.equals(종료))
{
System.exit(0);
}
else if (e.getSource() == save)
{
saveFile();
}
else if (e.getSource() == ok)
{

}

}

}

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