Cannot format given Object as a Number ComboBox

Question

How can I set an integer number into double? Let's say I have a comboBox named day, and it has 1,2,,3 elements. I want to set it as two decimal point. If user select 1, it will become 1.00. How can I do that?

public void actionPerformed(ActionEvent e){
                        String a=(String)comboBox.getSelectedItem();
                        //Integer b=(comboBox_1.getSelectedIndex()+1);
                        int day=(Integer)comboBox_2.getSelectedItem();
                        double bo;
                        DecimalFormat df = new DecimalFormat("#.##");      
                        bo= Double.valueOf(df.format(day));

Error I get

java.lang.IllegalArgumentException: Cannot format given Object as a Number
    at java.text.DecimalFormat.format(DecimalFormat.java:507)
    at java.text.Format.format(Format.java:157)
    at gui.User.<init>(User.java:105)
    at gui.User$1.run(User.java:49)

There's not enough code to reproduce your problem. `DecimalFormat.format(long)` (which you are calling in your code snippet) should work for all values of int. Are you sure the exception is from this line? — Codebender, Aug 24 '15 at 04:35
Use `DecimalFormat df = new DecimalFormat("#.00");` and then `df.format(day)`, No need for double conversion — Vaulstein, Aug 24 '15 at 04:37
is it possible to format an int comboBox to two decimal places like the way I did? — , Aug 24 '15 at 04:38
@anirudh How about comboBox? int day=(Integer)comboBox_2.getSelectedItem(); — , Aug 24 '15 at 04:39
sorry, I new to java, can't get it..can you explain more ? Thanks :) — , Aug 24 '15 at 04:43

Anoop B.K · Accepted Answer · 2015-08-24T05:44:48.707

1

Check this

public void actionPerformed(ActionEvent e){
                    String a=comboBox.getSelectedItem().toString();
                    //Integer b=(comboBox_1.getSelectedIndex()+1);
                    int day=Integer.ParseInt(comboBox_2.getSelectedItem().toString());
                    double bo;
                    DecimalFormat df = new DecimalFormat("#.##");      
                    bo=  Double.parseDouble(df.format(day));

edited Aug 24 '15 at 05:44

answered Aug 24 '15 at 04:44

Anoop B.K

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the bo cannot be double type...and I want it be double – Aug 24 '15 at 05:37
ya..change type of bo to String..cannot convert from string to double – Aug 24 '15 at 05:40
where is the string which is converting to double ? – Anoop B.K Aug 24 '15 at 05:42
the method doubleValue() is undefined for type string – Aug 24 '15 at 05:42
ok then this will help u.. Double.parseDouble(df.format(day)); – Anoop B.K Aug 24 '15 at 05:43

Cannot format given Object as a Number ComboBox

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