saving the enteries in an array

[Aroma Karim]

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

 class Proj2 extends JFrame implements ActionListener{
    JLabel label_1;
    JLabel label_2;
    JLabel label_3;
    JLabel label_4;
    JTextField textfield_1;
    JTextField textfield_2;
    JTextField textfield_3;
    JTextField textfield_4;
    JLabel label_5;
    ButtonGroup cbg;
    JRadioButton radio_1;
    JRadioButton radio_2;
    JLabel label_6;
    JButton button_1;
    JLabel label_9;
    JCheckBox checkbox_3;
    JButton button_4;
    JButton button_5;
    JButton button_6;
    JButton button_7;
    JComboBox combo = new JComboBox();

    public Proj2() {
        proj2Layout customLayout = new proj2Layout();

        getContentPane().setFont(new Font("Helvetica", Font.PLAIN, 12));
        getContentPane().setLayout(customLayout);

        label_1 = new JLabel("ID:");
        getContentPane().add(label_1);

        label_2 = new JLabel("Name:");
        getContentPane().add(label_2);

        label_3 = new JLabel("E-mail:");
        getContentPane().add(label_3);

        label_4 = new JLabel("Tel:");
        getContentPane().add(label_4);

        textfield_1 = new JTextField();
        getContentPane().add(textfield_1);

        textfield_2 = new JTextField();
        getContentPane().add(textfield_2);

        textfield_3 = new JTextField();
        getContentPane().add(textfield_3);

        textfield_4 = new JTextField();
        getContentPane().add(textfield_4);

        label_5 = new JLabel("Gender:");
        getContentPane().add(label_5);

        cbg = new ButtonGroup();
        radio_1 = new JRadioButton("Male", false);
        cbg.add(radio_1);
        getContentPane().add(radio_1);

        radio_2 = new JRadioButton("Female", false);
        cbg.add(radio_2);
        getContentPane().add(radio_2);

        label_6 = new JLabel("Department:");
        getContentPane().add(label_6);
          combo.addItem("Engineering");
    combo.addItem("Medicene");
    combo.addItem("Teaching");
     combo.addItem("Literuer");
    combo.addItem("Sience");
    combo.addItem("Drawing");
     getContentPane().add(combo);
        
        
     
        

        button_1 = new JButton(new ImageIcon("c:\\yy.jpg"));
        getContentPane().add(button_1);

        label_9 = new JLabel("Accept:");
        getContentPane().add(label_9);

        checkbox_3 = new JCheckBox("I accept every thing above and I will do every correct thing in this university");
        getContentPane().add(checkbox_3);

        button_4 = new JButton("Ok");
        getContentPane().add(button_4);
        button_4.setBackground(Color.ORANGE);

        button_5 = new JButton("Save");
        getContentPane().add(button_5);
         button_5.setBackground(Color.ORANGE);
         button_5.addActionListener(this);

        button_6 = new JButton("Refresh");
        getContentPane().add(button_6);
         button_6.setBackground(Color.ORANGE);
         button_6.addActionListener(this);

        button_7 = new JButton("Exite");
        getContentPane().add(button_7);
         button_7.setBackground(Color.ORANGE);
         button_7.addActionListener(this);

        setSize(getPreferredSize());
        setVisible(true);

        
    }

    

class proj2Layout implements LayoutManager {

    public proj2Layout() {
    }

    @Override
    public void addLayoutComponent(String name, Component comp) {
    }

    @Override
    public void removeLayoutComponent(Component comp) {
    }

    @Override
    public Dimension preferredLayoutSize(Container parent) {
        Dimension dim = new Dimension(0, 0);

        Insets insets = parent.getInsets();
        dim.width = 750 + insets.left + insets.right;
        dim.height = 450 + insets.top + insets.bottom;

        return dim;
    }

    @Override
    public Dimension minimumLayoutSize(Container parent) {
        Dimension dim = new Dimension(0, 0);
        return dim;
    }

    @Override
    public void layoutContainer(Container parent) {
        Insets insets = parent.getInsets();

        Component c;
        c = parent.getComponent(0);
        if (c.isVisible()) {c.setBounds(insets.left+16,insets.top+40,48,24);}
        c = parent.getComponent(1);
        if (c.isVisible()) {c.setBounds(insets.left+224,insets.top+40,56,24);}
        c = parent.getComponent(2);
        if (c.isVisible()) {c.setBounds(insets.left+16,insets.top+88,72,24);}
        c = parent.getComponent(3);
        if (c.isVisible()) {c.setBounds(insets.left+224,insets.top+88,40,24);}
        c = parent.getComponent(4);
        if (c.isVisible()) {c.setBounds(insets.left+96,insets.top+40,104,24);}
        c = parent.getComponent(5);
        if (c.isVisible()) {c.setBounds(insets.left+296,insets.top+40,120,24);}
        c = parent.getComponent(6);
        if (c.isVisible()) {c.setBounds(insets.left+96,insets.top+88,104,24);}
        c = parent.getComponent(7);
        if (c.isVisible()) {c.setBounds(insets.left+296,insets.top+88,120,24);}
        c = parent.getComponent(8);
        if (c.isVisible()) {c.setBounds(insets.left+16,insets.top+136,72,24);}
        c = parent.getComponent(9);
        if (c.isVisible()) {c.setBounds(insets.left+88,insets.top+184,72,24);}
        c = parent.getComponent(10);
        if (c.isVisible()) {c.setBounds(insets.left+240,insets.top+184,72,24);}
        c = parent.getComponent(11);
        if (c.isVisible()) {c.setBounds(insets.left+16,insets.top+232,88,24);}
        c = parent.getComponent(12);
        if (c.isVisible()) {c.setBounds(insets.left+100,insets.top+232,100,30);}
        
        c = parent.getComponent(13);
        if (c.isVisible()) {c.setBounds(insets.left+458,insets.top+24,264,368);}
        c = parent.getComponent(14);
        if (c.isVisible()) {c.setBounds(insets.left+16,insets.top+280,80,24);}
        c = parent.getComponent(15);
        if (c.isVisible()) {c.setBounds(insets.left+16,insets.top+320,450,24);}
        c = parent.getComponent(16);
        if (c.isVisible()) {c.setBounds(insets.left+16,insets.top+368,72,30);}
        c = parent.getComponent(17);
        if (c.isVisible()) {c.setBounds(insets.left+104,insets.top+368,72,30);}
        c = parent.getComponent(18);
        if (c.isVisible()) {c.setBounds(insets.left+192,insets.top+368,80,30);}
        c = parent.getComponent(19);
        if (c.isVisible()) {c.setBounds(insets.left+280,insets.top+368,72,30);}
    }
}
    @Override
    public void actionPerformed(ActionEvent m)  
    {  
          
          
        if(m.getSource()==button_7)  
        {  
        	setVisible(false);
        }
         if(m.getSource()==button_6){
        	  textfield_1.setText("");
        	   textfield_2.setText("");
        	    textfield_3.setText("");
        	     textfield_4.setText("");
                  combo.setSelectedIndex(0);
        	      cbg.clearSelection();
        	      checkbox_3.setSelected(false);
        	
        }
         if(m.getSource()==button_5){
         
     AddStudent();    
         }
    }
        
public static void main(String args[]) {
        Proj2 proj2;
        proj2 = new Proj2();

      
}

void AddStudent(){


	Student std[]=new Student[1000];
        	int IDnum_1=Integer.parseInt(textfield_1.getText());
        	String name_1=textfield_2.getText();
        	String EMail_1=textfield_3.getText();
        	int Tel_1;
        Tel_1 = Integer.parseInt(textfield_4.getText());
        	String major_1=String.valueOf(combo.getSelectedItem());
       
        	int i;
        	
        	
        
        	boolean radio_11=radio_1.isSelected();
        	   	boolean radio_12=radio_2.isSelected();
        	   	for( i=0;i<1000;i++){
        	   		std[i].name=name_1;
        	   		std[i].IDnum=IDnum_1;
        	   		std[i].EMail=EMail_1;
        	   		std[i].major=major_1;
        	   		
        	   		
        	   		
        	   	}
        	   	}
}

I want to put the enteries in textfields in an array I tryed every thing in my mind but failed
i still have errors
ERRORS:
--------------------Configuration: <Default>--------------------
Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: ""
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
at java.lang.Integer.parseInt(Integer.java:470)
at java.lang.Integer.parseInt(Integer.java:499)
at Proj2.AddStudent(proj2.java:234)
at Proj2.actionPerformed(proj2.java:219)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
at java.awt.Component.processMouseEvent(Component.java:6297)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3275)
at java.awt.Component.processEvent(Component.java:6062)
at java.awt.Container.processEvent(Container.java:2039)
at java.awt.Component.dispatchEventImpl(Component.java:4660)
at java.awt.Container.dispatchEventImpl(Container.java:2097)
at java.awt.Component.dispatchEvent(Component.java:4488)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4575)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4236)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4166)
at java.awt.Container.dispatchEventImpl(Container.java:2083)
at java.awt.Window.dispatchEventImpl(Window.java:2489)
at java.awt.Component.dispatchEvent(Component.java:4488)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:668)
at java.awt.EventQueue.access$400(EventQueue.java:81)
at java.awt.EventQueue$2.run(EventQueue.java:627)
at java.awt.EventQueue$2.run(EventQueue.java:625)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$3.run(EventQueue.java:641)
at java.awt.EventQueue$3.run(EventQueue.java:639)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:638)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

[Tony Docherty]

The error message states you are trying to convert a "" to a number which can't be done.
You either need to test to see if the string is empty (and possibly if it is null) before trying to convert it or catch the NumberFormatException locally and handle it there or use a JFomattedText component configured for integer values (this approach is more complex than the others but will ensure the user can only enter numeric characters).