从jtable中获取双精度值

Question

I found a few threads with a similar problem, but nothing worked for me. I'm trying to get a double and a string value out of a jtable. I'm using the DefaultTableModel and did override the getCOlumnClass method:

private void initTable()
{
    String tableColumns[] = { language.getTranslatedPhrase(MultilanguageUtil.Amount),
            language.getTranslatedPhrase(MultilanguageUtil.Ingredient),
            language.getTranslatedPhrase(MultilanguageUtil.Unit) };

    tableModel = new DefaultTableModel(tableColumns, 0) {
        private static final long serialVersionUID = 1L;  
         @Override
        public Class<?> getColumnClass(int column) {  
                switch (column) {  
                    case 0:
                        return Double.class;
                    case 1:  
                        return String.class;
                    case 2:  
                        return Units.class; 
                    default:
                        return String.class;
                }  
       }
    };


    table = new JTable(tableModel);

I'm expecting double values in the first column, but when i try to get a value with:

int rowCount = tableModel.getRowCount();

for (int i = 1; i <= rowCount - 1; i++)
{
    double doubleValue = (Double) tableModel.getValueAt(i, 0);
}

I get this exception:

Exception in thread "AWT-EventQueue-0" java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.Double

I have also tried this:

Object objValue = tableModel.getValueAt(i, 0);
        double doubleValue = ((Double) objValue).doubleValue();

but i get the same exception.

when i excecute

System.out.println(table.getColumnClass(0));

it says

class java.lang.Double

so, it seems to be right, but i still get the exception, which says that its an integer, and i can't cast it to a double...

I hope someone could help me, and sorry for my bad english!(not my first language)

Answer 1

Well, to fix the error you should not put Integer s to the cell that you explicitly defined to have double values. You can work around it like this: use String.valueOf() to make a String from your input. This method accepts many variable types. Then from String , you can Double.parseDouble() . For example

double doubleValue = Double.parseDouble(String.valueOf(tableModel.getValueAt(i, 0)));

Is a bit hackey but works.