java - How to parse an integer, when I have a format for a double? -

i'm taking user entries database, stores values user entered might either float or int, code meant check following condition

string pattern = "###,###.##";         decimalformat decimalformat = new decimalformat(pattern); if (!userput.equals("")){         resultoutput.settext(""+double.parsedouble(userput)*double.parsedouble(decimalformat.format(double.parsedouble(x[1]))));}         else{             userinput.settext("1");             resultoutput.settext(""+double.parsedouble(decimalformat.format(double.parsedouble(x[1]))));         } 

so when encounters int crashes. example, 13152 gives java.lang.numberformatexception: invalid double: "13,152"

moreover if output 13170.00 error follows java.lang.numberformatexception: invalid double: "13,170.00"

sometimes values fetched database contains float , integer, here x[1] currency exchange rate , userinput contains integer or float....lets trying usd idr currency 13170.00 not double neither int because error java.lang.numberformatexception: invalid double: "13,170.00"

your problem not in whether number integer or double. problem lies in fact conversion rate has more 3 digits.

this code displaying value (reformatted):

resultoutput.settext(     ""     + double.parsedouble(userput)     * double.parsedouble(decimalformat.format(double.parsedouble(x[1])))); 

so, are:

1. taking exchange rate, string, , converting double.
2. taking resulting double, , converting string, using decimal format.
3. taking formatted text, , converting again double
4. multiplying double value of user input
5. converting result string (without formatting).

the problem lies in step 2 , 3. unnecessary. numbers work.

your format ###,###.##. let's see how numbers when formatted format:

 ╔═════════╤═══════════╗ ║ number  │ formatted ║ ╠═════════╪═══════════╣ ║ 0.273   │ 0.27      ║ ╟─────────┼───────────╢ ║ 5.3     │ 5.3       ║ ╟─────────┼───────────╢ ║ 358.2   │ 358.2     ║ ╟─────────┼───────────╢ ║ 10.0    │ 10        ║ ╟─────────┼───────────╢ ║ 1298.52 │ 1,298.52  ║ ╚═════════╧═══════════╝

so, when have conversion rates smaller 4 digits left of decimal point, decimalformat.format() call converts them string still legal java double. when call double.parsedouble on string in step 3, good.

but when have large number, such "13152.00", is:

1. convert double: 13152.0
2. convert string format: 13,152.0
3. convert double: - doesn't work. java not accepting , in input double.parsedouble().

so really, conversion should be:

resultoutput.settext(     ""     + double.parsedouble(userput)     * double.parsedouble(x[1])); 

this give proper, unformatted number in resultoutput, without throwing exception.

i'm pretty sure intended decimalformat in order display number, not in order convert again , again. means should use on result of conversion - instead of doing "" + ..., gives default formatting.

resultoutput.settext(     decimalformat.format( double.parsedouble(userput) * double.parsedouble(x[1]))); 

be warned, though, not see 2 digits after decimal point format - display 10.0 10. if want display 2 digits, have use ###,##0.00 format.