Change colour of cell

You're using "creditColumn" to calculate amt, while you're using "column" in you method definition.

only apply the renderer to that column instead of all of them

can you both please explain more or give me reference from my code.appreciate your help

OK i updated my code.but still i have the same problem

private class CustomeTableCellRenderer extends DefaultTableCellRenderer
	{
		private static final long serialVersionUID = 1L;
		
		public Component getTableCellRendererComponent(JTable table,
				Object value, boolean isSelected, boolean hasFocus, int row,
				int column) 
		{
			Component comp = super.getTableCellRendererComponent(table,  value, isSelected, hasFocus, row, creditColumn);
			System.out.println(row+" "+column);
			//int days=Integer.parseInt(table.getModel().getValueAt(row,creditColumn).toString());
			float amt=Float.parseFloat(table.getModel().getValueAt(row,creditColumn).toString());
			if(amt>0)
			{
				//comp.setForeground(Color.green);
			}else
			{
				//comp.setForeground(table.getForeground());
			}
			return comp;
		}
	}

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Wild guess:

change

float amt=Float.parseFloat(table.getModel().getValueAt(row,creditColumn).toString());

to

float amt=Float.parseFloat(table.getModel().getValueAt(row,column).toString());

And don't comment out the "comp.setForeground(Color.green)

i get this exception
Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: "abcdef"
      at sun.misc.FloatingDecimal.readJavaFormatString(Unknown Source)
      at java.lang.Float.parseFloat(Unknown Source)
      at custom.java.swing.PurchaseDetailFrame$CustomeTableCellRenderer.getTableCellRendererComponent(PurchaseDetailFrame.java:684)
      at javax.swing.JTable.prepareRenderer(Unknown Source)
      at javax.swing.plaf.basic.BasicTableUI.paintCell(Unknown Source)
      at javax.swing.plaf.basic.BasicTableUI.paintCells(Unknown Source)
      at javax.swing.plaf.basic.BasicTableUI.paint(Unknown Source)
      at javax.swing.plaf.ComponentUI.update(Unknown Source)

This means not every cell in your table contains a float value. There's at least one cell with the value "abcdef" in it.

If you need to be able to change the foreground of every single cell in the table you should do a check first to see what column you're in and if it contains a float value.

If you know which column(s) contains a float value, install the renderer simply for that/those column(s). To do this you use:

    JTable.setDefaultRenderer(Class<?> columnClass, TableCellRenderer renderer)

so

   table.setDefaultRenderer(Float.class, new CustomeTableCellRenderer());

In your table model you define the column(s) containing the floats as being of type Float.class.

Bart_Cr:

thanks for your comment.look at the screenshot.to give you a better idia to what i am trying to acheive.

the code is what i get now in the scrren shot.

private class CustomeTableCellRenderer extends DefaultTableCellRenderer
	{
		private static final long serialVersionUID = 1L;
		
		public Component getTableCellRendererComponent(JTable table,
				Object value, boolean isSelected, boolean hasFocus, int row,
				int column) 
		{
			Component comp = super.getTableCellRendererComponent(table,  value, isSelected, hasFocus, row, creditColumn);
			System.out.println(row+" "+creditColumn);
			//int days=Integer.parseInt(table.getModel().getValueAt(row,creditColumn).toString());
			//float amt=Float.parseFloat(table.getModel().getValueAt(row,creditColumn).toString());
			
			float amt=Float.parseFloat(table.getModel().getValueAt(row,creditColumn).toString());
 
			if(amt>0)
			{
				comp.setForeground(Color.green);
			}else
			{
				comp.setForeground(table.getForeground());
			}
			return comp;
		}
	}

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1.JPG

Could you provide the code for your TableModel?

purchaseTableModel=new DefaultTableModel(){
			private static final long serialVersionUID = 1L;
 
			public boolean isCellEditable(int row, int column) {
				if(column==3)
				{
					return true;
				}else
				{
					return false;
				}
			}
			
			public Class<?> getColumnClass(int columnIndex) {
				switch (columnIndex) {
				case debitColumn:
				case creditColumn:
					return Float.class;
				default: return Object.class;
				}
			}
};
 
		purchaseTableModel.setColumnIdentifiers(new String[]{"Sr.No.","Code","Name","Comment","Debit","Credit"});
 
		table=new JTable(purchaseTableModel);

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You can use

   table.getColumnModel().getColumn(creditColumn).setCellRenderer(new CustomeTableCellRenderer());

This at the place you construct your table.

This makes sure only the renderer only works for this one column. You'll need to remove the default cellrenderer for Float.class though

at present i have this what do i do.

table=new JTable(purchaseTableModel);
            defaultForeground=table.getForeground();
            table.setDefaultRenderer(Object.class,new CustomeTableCellRenderer());
            table.setAutoCreateRowSorter(true);
            
>>You'll need to remove the default cellrenderer for Float.class though
where is this

Remove the setDefaultRenderer(Object.class ...)

yes that did the trick but the debit column has lost its alignment.see the screenshot.
also can i only change the colour of 900 in credt column to red.

screenshot
2.JPG

also the column should be creditcolumn or column

private class CustomeTableCellRenderer extends DefaultTableCellRenderer
	{
		private static final long serialVersionUID = 1L;
		
		public Component getTableCellRendererComponent(JTable table,
				Object value, boolean isSelected, boolean hasFocus, int row,
				int column) 
		{
			Component comp = super.getTableCellRendererComponent(table,  value, isSelected, hasFocus, row, column);
			System.out.println(row+" "+creditColumn);
			//int days=Integer.parseInt(table.getModel().getValueAt(row,creditColumn).toString());
			//float amt=Float.parseFloat(table.getModel().getValueAt(row,creditColumn).toString());
			//table.setDefaultRenderer(Float.class, new CustomeTableCellRenderer());
 
			float amt=Float.parseFloat(table.getModel().getValueAt(row,column).toString());
 
			if(amt>0)
			{
				comp.setForeground(Color.green);
			}else
			{
				comp.setForeground(table.getForeground());
			}
			return comp;
		}
	}

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The alignment of the debit column is defined by it's class. Because it's a float, java uses a Default renderer for numeric values and thus right alignment. If you don't want this you'll need to change the class of the column or add another custom renderer for the debit column.

In your custom renderer you can check the value and change the foreground depending on the value. Simply add more checks and set it to another color as required.

so i create two customcellrenderer.one for debitcolumn and one for creditcolumn.


also can i only change the colour of 900 in credt column to red.how can i do this.

I don't know what your specific requirements are there, but:

if (amt == 900) {
   comp.setForeground(Color.red);
} else if (amt>0) {
   comp.setForeground(Color.green);
} else {
    comp.setForeground(table.getForeground());
}

OK.Thanks
one last question.how can i get the row and column of cell where i am adding these values.the code below is where i add the values from db into the table.

stmt=conn.prepareStatement("SELECT
                  
                  stmt.setInt(1,receiptID);
                  rs=stmt.executeQuery();
                  while(rs.next())
                  {
                        
                        String value = rs.getString(2);
                        value = value + "  (Commission)";
                        addRowDiscount(rs.getInt(1),value,
                                    null,rs.getFloat(3),0,
                                    purchaseTableModel);
                        
                  }

I'm not entirely sure what your question is here

i want to get the row and column number from the tablemodel purchaseTableModel in the method addRowDiscount

Thanks mate for your time and patience

You can't simply get them as you define everything yourself in the tablemodel.