hi
im getting a nullPointerException on line 114 and 159 when i try to run the program after compiling the code succesfully,
Any help with why would be greatly appreciated.
(Errors Marked in Bold)
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.Graphics;
public class AssignSem2 extends JFrame
{
private JButton b,con;
private JRadioButton b1,b2,b3;
private ButtonGroup radioGroup;
private JList list;
private
String listStuff[]={"E 6 (20%)","E 12 (10%)","E 24 (05%)"};
private JTextField in, out;
private GridLayout grid;
private Graphics rb,rb1,rb2,rb3,rb4,rb5; //resistor base, resistor band 1-4
/************************ Creating The GUI *****************************/
public AssignSem2()
{
super ("Unit Converter");
/********************** File Menu **************************/
JMenu fileMenu = new JMenu( "File");
fileMenu.setMnemonic('F');
JMenuItem exitItem = new JMenuItem("Exit");
exitItem.setMnemonic('x');
fileMenu.add(exitItem);
exitItem.addActionListener(
new ActionListener()
{
public void actionPerformed(ActionEvent event)
{
System.exit(0);
}
}
);
JMenuBar bar = new JMenuBar();
setJMenuBar(bar);
bar.add(fileMenu);
JMenu helpMenu = new JMenu("Help");
helpMenu.setMnemonic('H');
JMenuItem aboutItem = new JMenuItem( "About...");
aboutItem.setMnemonic( 'A' );
helpMenu.add(aboutItem);
aboutItem.addActionListener(
new ActionListener()
{
public void actionPerformed(ActionEvent event)
{
new About();
}
});
JMenuItem instructionsItem = new JMenuItem("Instructions");
instructionsItem.setMnemonic( 'I' );
helpMenu.add(instructionsItem);
instructionsItem.addActionListener(
new ActionListener()
{
public void actionPerformed(ActionEvent event)
{
new Instructions();
}
});
bar.add(helpMenu);
/*************************************************************/
grid = new GridLayout(3,3,5,5); // Creating Grid Layout
Container c=getContentPane(); // Creates Main Window
c.setLayout(grid);
in=new JTextField ("Insert Value Here",15);
c.add(in); // Creates Input Field
con=new JButton("->Convert->"); // Creates Convert Button
c.add(con);
out=new JTextField ("Output",15); // Output Field
out.setEditable(false);
c.add(out);
b1=new JRadioButton("Ohms");
c.add(b1);
b2=new JRadioButton("Farads"); // Radoi Buttons
c.add(b2);
b3=new JRadioButton("Henrys");
c.add(b3);
radioGroup = new ButtonGroup(); // Groups Radio Buttons
radioGroup.add(b1);
radioGroup.add(b2);
radioGroup.add(b3);
b=new JButton("Quit"); // Quit Button
b.setToolTipText("Push The Button to exit");
b.addActionListener(
new ActionListener()
{
public void actionPerformed(ActionEvent e ){
System.exit(0);
}
}
);
c.add(b);
list=new JList (listStuff);
list.setVisibleRowCount(3); // Tolerence List
list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
c.add(new JScrollPane(list));
rb.setColor(new Color(255,231,186));
<-Error Here rb.fillRect(250,115,100,20);
rb1.setColor(new Color(255,231,186));
rb1.fillRect(270,115,10,20);
rb2.setColor(new Color(255,231,186));
rb2.fillRect(290,115,10,20);
rb3.setColor(new Color(255,231,186));
rb3.fillRect(310,115,10,20);
rb4.setColor(new Color(255,231,186));
rb4.fillRect(330,115,10,20);
rb5.setColor(new Color(255,231,186));
rb5.fillRect(350,115,10,20);
addWindowListener
(
new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
System.exit(0);
}
}
);
setSize(360,180);
setLocation(100,100); // Sets size and location
setResizable(false); // of main window
show();
try {
jbInit();
}
catch(Exception e) {
e.printStackTrace();
}
}
private void jbInit() throws Exception {
this.getContentPane().setBackground(new java.awt.Color(205,205,205));
this.setFont(new java.awt.Font("Sans Serif", 0, 12));
}
/************************* Main Method **********************************/
public static void main (String args[])
{
new AssignSem2();
<-Error Here }
}