Java automatically calculates the sum of a numeric column in a table

[Java]
Package com. han;
 
Import java. awt. BorderLayout;
Import java. awt. Container;
Import java. util. Vector;
 
Import javax. swing. JFrame;
Import javax. swing. JLabel;
Import javax. swing. JOptionPane;
Import javax. swing. JPanel;
Import javax. swing. JScrollPane;
Import javax. swing. JTable;
Import javax. swing. JTextField;
Import javax. swing. event. TableModelEvent;
Import javax. swing. event. TableModelListener;
Import javax. swing. table. DefaultTableModel;
 
/**
* Automatically calculates the sum of a numeric column in a table.
* @ Author HAN
*
*/
Public class TabelModelEvent_2 extends JFrame {
 
/**
*
*/
Private static final long serialVersionUID = 7045416728019138021L;
 
Float sum = 0;
 
Public TabelModelEvent_2 (){
// TODO Auto-generated constructor stub
Final Container container = getContentPane ();
JScrollPane scrollPane = new JScrollPane ();
Vector <String> tableNames = new Vector <String> ();
TableNames. add ("Number Column ");
Vector <String> tableValues = new Vector <String> ();
For (int I = 0; I <4; I ++ ){
Vector <String> vector = new Vector <String> ();
Vector. add (null );
TableValues. add (vector );
}
Final DefaultTableModel defaultTabelModel = new DefaultTableModel (
TableValues, tableNames );
JTable table = new JTable (defaultTabelModel );
ScrollPane. setViewportView (table );
Container. add (scrollPane, BorderLayout. CENTER );
JPanel panel = new JPanel ();
JLabel label = new JLabel ("total number columns :");
Final JTextField textField = new JTextField (10 );
Panel. add (label );
Panel. add (textField );
Container. add (panel, BorderLayout. SOUTH );
 
DefaultTabelModel. addTableModelListener (new TableModelListener (){
 
@ Override
Public void tableChanged (TableModelEvent e ){
// TODO Auto-generated method stub
If (e. getType () = TableModelEvent. UPDATE ){
Int row = e. getFirstRow ();
Int column = e. getColumn ();
 
// Keep that every cell value is float or null.
Try {
Float. parseFloat (String) defaultTabelModel. getValueAt (
Row, column ));
} Catch (NumberFormatException e1 ){
JOptionPane. showMessageDialog (container,
"Your input object is not a float type ");
DefaultTabelModel. setValueAt (null, row, column );
} Catch (NullPointerException e2 ){
// Do nothing
}
 
For (int I = 0; I <4; I ++ ){
Object cellValue = defaultTabelModel. getValueAt (I, 0 );
If (cellValue! = Null ){
 
Float floatValue = Float
. ParseFloat (String) cellValue );
Sum + = floatValue;
 
}
}
}
TextField. setText (new Float (sum). toString ());
Sum = 0;
}
 
});
}
 
/**
* @ Param args
*/
Public static void main (String [] args ){
// TODO Auto-generated method stub
TabelModelEvent_2 frame = new TabelModelEvent_2 ();
Frame. setTitle ("automatically calculate the sum of a numeric column in a table ");
Frame. pack ();
Frame. setVisible (true );
Frame. setdefaclocloseoperation (JFrame. EXIT_ON_CLOSE );
}
 
}

Package com. han;

Import java. awt. BorderLayout;
Import java. awt. Container;
Import java. util. Vector;

Import javax. swing. JFrame;
Import javax. swing. JLabel;
Import javax. swing. JOptionPane;
Import javax. swing. JPanel;
Import javax. swing. JScrollPane;
Import javax. swing. JTable;
Import javax. swing. JTextField;
Import javax. swing. event. TableModelEvent;
Import javax. swing. event. TableModelListener;
Import javax. swing. table. DefaultTableModel;

/**
* Automatically calculates the sum of a numeric column in a table.
* @ Author HAN
*
*/
Public class TabelModelEvent_2 extends JFrame {

/**
*
*/
Private static final long serialVersionUID = 7045416728019138021L;

Float sum = 0;

Public TabelModelEvent_2 (){
// TODO Auto-generated constructor stub
Final Container container = getContentPane ();
JScrollPane scrollPane = new JScrollPane ();
Vector <String> tableNames = new Vector <String> ();
TableNames. add ("Number Column ");
Vector <String> tableValues = new Vector <String> ();
For (int I = 0; I <4; I ++ ){
Vector <String> vector = new Vector <String> ();
Vector. add (null );
TableValues. add (vector );
}
Final DefaultTableModel defaultTabelModel = new DefaultTableModel (
TableValues, tableNames );
JTable table = new JTable (defaultTabelModel );
ScrollPane. setViewportView (table );
Container. add (scrollPane, BorderLayout. CENTER );
JPanel panel = new JPanel ();
JLabel label = new JLabel ("total number columns :");
Final JTextField textField = new JTextField (10 );
Panel. add (label );
Panel. add (textField );
Container. add (panel, BorderLayout. SOUTH );

DefaultTabelModel. addTableModelListener (new TableModelListener (){

@ Override
Public void tableChanged (TableModelEvent e ){
// TODO Auto-generated method stub
If (e. getType () = TableModelEvent. UPDATE ){
Int row = e. getFirstRow ();
Int column = e. getColumn ();

// Keep that every cell value is float or null.
Try {
Float. parseFloat (String) defaultTabelModel. getValueAt (
Row, column ));
} Catch (NumberFormatException e1 ){
JOptionPane. showMessageDialog (container,
"Your input object is not a float type ");
DefaultTabelModel. setValueAt (null, row, column );
} Catch (NullPointerException e2 ){
// Do nothing
}

For (int I = 0; I <4; I ++ ){
Object cellValue = defaultTabelModel. getValueAt (I, 0 );
If (cellValue! = Null ){

Float floatValue = Float
. ParseFloat (String) cellValue );
Sum + = floatValue;

}
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}
TextField. setText (new Float (sum). toString ());
Sum = 0;
}

});
}

/**
* @ Param args
*/
Public static void main (String [] args ){
// TODO Auto-generated method stub
TabelModelEvent_2 frame = new TabelModelEvent_2 ();
Frame. setTitle ("automatically calculate the sum of a numeric column in a table ");
Frame. pack ();
Frame. setVisible (true );
Frame. setdefaclocloseoperation (JFrame. EXIT_ON_CLOSE );
}

}

Author: Gaowen_HAN