//包名
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.text.ParseException;

public class DecimalFormatTest
{
    
    public static void main(String[] args)
    {
        DecimalFormat df = new DecimalFormat("###,###.##");
        
        NumberFormat nf = NumberFormat.getInstance();
        try
        {
            System.out.println(df.format((nf.parse("123123.12"))));
        }
        catch (ParseException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
        
    }
    
}