change cell color does not work on netbeans

Question

I created desktop application with Netbeans, and I want to change a particular cell color if it has string value of "on Process". I tried

class CustomTableCellRenderer extends DefaultTableCellRenderer{
    public Component getTableCellRendererComponent (JTable table, Object obj,
            boolean isSelected, boolean hasFocus, int row, int column) {
        Component cell = super.getTableCellRendererComponent(
            table, obj, isSelected, hasFocus, row, column);
        if (obj=="on Process") {
            cell.setBackground(Color.green);
        } 
        return cell;
    }
}

but it is not changing my tableI used

table.getColumnModel().getColumn(7).setCellRenderer(new CustomTableCellRenderer());

I`m getting values from database and using

for(int i=0; i<arraylist.size(); i++) {
    table.setValueAt(status, i, 7);
}

here status is String, if I type manually like:

table.setValueAt("on Process", i, 7);

it changes the color, it is fine, but I can not type it like that, I need to set value from variable. I tried String, Object, no use! I tried toString(), I tried ""+status, ... it is just ignoring what I assign to it. Inside forloop if I type "on Process" it works, but outside forloop I can assign from variable, it changes color. I am confused, don`t know what to do. Please help me.

score 4 · Answer 1 · answered Apr 13 '12 at 16:42

4

You need this:

if(obj.toString().equals("on Process"))

instead of:

if(obj=="on Process")

answered Apr 13 '12 at 16:42

Eng.Fouad

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Thanks for reply. But if I use if(obj.toString().equals("on Process")) It is throwing NullPointerException. – Jamol Apr 13 '12 at 16:59
@user1290988 then use, `if(obj != null && obj.toString().equals("on Process"))` – Eng.Fouad Apr 13 '12 at 18:44

score 1 · Answer 2 · edited May 23 '17 at 11:49

1

@Eng.Fouad is right about distinguishing between equals() and ==. You'll also need to verify that your TableModel returns the desired type token for your specified column, as shown in this example. The DefaultTableModel simply returns Object.class.

edited May 23 '17 at 11:49

Community

1
1

answered Apr 14 '12 at 02:30

trashgod

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columnClasss often is the culprit - shouldn't in this context as the OP is using a per-column renderer. Which might be the problem, if the update from the database triggers a structureChanged. @user1290988, does it? – kleopatra Apr 14 '12 at 09:10
@kleopatra is right: `getCellRenderer()` should find the `TableColumn`'s renderer first. A `fireTableStructureChanged()` may cause the "types of the new columns may be different." No change would explain why `setValueAt()` with a `String` literal finds the column renderer. – trashgod Apr 14 '12 at 17:18

change cell color does not work on netbeans

2 Answers2