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how to convert currency format to double in java

I am getting value in currency formate, but i want double format only.
String amt = txn.getAmount();
System.out.println("--amt--"+amt);//output:1010
double value = Double.parseDouble(amt);
System.out.println("---value---"+value);//output:1010.0
String ammount=NumberFormat.getCurrencyInstance().format(value);
System.out.println("--ammount--"+ammount);//output:Rs.1,010.00
Here i want Rs.1,010.00 to 1010.00
Any mistakes in my code?

I assume you do not want the currency details. In that case, use getNumberInstance() instead of getCurrencyInstance().
Use:
NumberFormat nf = NumberFormat.getNumberInstance();
nf.setGroupingUsed(false);
nf.setMinimumFractionDigits(2);
String ammount= nf.format(value);

Before printing, replace the string "Rs." with "" and also "," with "".
String replaceString1=amount.replace("Rs.","");
String replaceString2=amount.replace(",","");
This is a way to handle this case.
Hope this helps.

Try this cleaner approach!.
double d = 1010.00;
Locale uk = new Locale("en", "GB");
NumberFormat cf = NumberFormat.getCurrencyInstance(uk);
String s = cf.format(d);
System.out.println(s);
Number number = null;
try
{
number = cf.parse(s);
}
catch (ParseException e)
{
System.out.print(e);
}
double dClone = number.doubleValue();

convert String to double with '%'

I have a String value like "1.22%". I want to convert this to double value.
Douboe.parseDouble throws numberFormatException.
String s = "1.22%";
double iRate;
iRate = Double.parseDouble(s);

One-liner using DecimalFormat:
double d = new DecimalFormat("0.0#%").parse("1.22%").doubleValue();
// d = 0.0122

You want to use a method similar to the one below:
public static double ConvertPercentageStringToDouble(this string value)
{
return double.Parse(value.Replace("%","")) / 100;
}

Assuming you have standard format. You can try
String s = "1.22%";
s = s.replaceAll("%","");
double iRate= Double.parseDouble(s);

The better way to do this is using DecimalFormatSymbols, which can help you to define what is simbols and what is really numbers to transform into Double.
See the example below:
String s = "1.22%";
DecimalFormat df = new DecimalFormat();
DecimalFormatSymbols symbols = new DecimalFormatSymbols();
symbols.setDecimalSeparator('.');
symbols.setGroupingSeparator(' ');
symbols.setPercent('%');
df.setDecimalFormatSymbols(symbols);
Number parse = df.parse(s);
Double myDouble = parse.doubleValue();
System.out.println(myDouble);

How to write string with 3 significant digits without rounding

I would like the convert string value with 3 significant digits.
I am using this code :
String s = "0,92";
float f = Float.parseFloat(s);
DecimalFormat formatter = new DecimalFormat("#,###");
String end = formatter.format(f);
The result is end= 0.000. But ı want to get end = 0,920. How can i do that?

If in your current locale the decimal separator is a dot then you will get 0.920. If you want to get the result independent from you current locale to have as decimal separator a comma and as thousand separator a dot you could achieve it for example like this
String s = "0.92";
float f = Float.parseFloat(s);
DecimalFormat formatter = new DecimalFormat("0.000", DecimalFormatSymbols.getInstance(Locale.GERMANY));
String end = formatter.format(f);
System.out.println("end = " + end);
This prints
end = 0,920

This works for me:
String s = "0.92";
float f = Float.parseFloat(s);
DecimalFormat formatter = new DecimalFormat("0.000");
String end = formatter.format(f);
System.out.println(end);
Please note the '.' in the String s and the pattern in DecimalFormat.
',' here means the 1000 marker, ie. 1,000,000.00 for one million.

Convert String with Dot or Comma to Float Number

I always like input in my function to get numbers that range from 0.1 to 999.9 (the decimal part is always separated by '.', if there is no decimal then there is no '.' for example 9 or 7 .
How do I convert this String to float value regardless of localization (some countries use ',' to separate decimal part of number. I always get it with the '.')? Does this depend on local computer settings?

The Float.parseFloat() method is not locale-dependent. It expects a dot as decimal separator. If the decimal separator in your input is always dot, you can use this safely.
The NumberFormat class provides locale-aware parse and format should you need to adapt for different locales.

DecimalFormatSymbols symbols = new DecimalFormatSymbols();
symbols.setDecimalSeparator('.');
DecimalFormat format = new DecimalFormat("0.#");
format.setDecimalFormatSymbols(symbols);
float f = format.parse(str).floatValue();

valueStr = valueStr.replace(',', '.');
return new Float(valueStr);
Done

See java.text.NumberFormat and DecimalFormat:
NumberFormat nf = new DecimalFormat ("990.0");
double d = nf.parse (text);

What about this:
Float floatFromStringOrZero(String s){
Float val = Float.valueOf(0);
try{
val = Float.valueOf(s);
} catch(NumberFormatException ex){
DecimalFormat df = new DecimalFormat();
Number n = null;
try{
n = df.parse(s);
} catch(ParseException ex2){
}
if(n != null)
val = n.floatValue();
}
return val;
}

You can use the placeholder %s-String for any primitive type.
float x = 3.15f, y = 1.2345f;
System.out.printf("%.4s and %.5s", x, y);
Output: 3.15 and 1.234
%s is always english formatting regardless of localization.
If you want a specif local formatting, you could also do:
import java.util.Locale;
float x = 3.15f, y = 1.2345f;
System.out.printf(Locale.GERMAN, "%.2f and %.4f", x, y);
Output: 3,15 and 1,2345

I hope this piece of code may help you.
public static Float getDigit(String quote){
char decimalSeparator = new DecimalFormatSymbols().getDecimalSeparator();
String regex = "[^0-9" + decimalSeparator + "]";
String valueOnlyDigit = quote.replaceAll(regex, "");
if (String.valueOf(decimalSeparator).equals(",")) {
valueOnlyDigit = valueOnlyDigit.replace(",", ".");
//Log.i("debinf purcadap", "substituted comma by dot");
}
try {
return Float.parseFloat(valueOnlyDigit);
} catch (ArithmeticException | NumberFormatException e) {
//Log.i("debinf purcadap", "Error in getMoneyAsDecimal", e);
return null;
}
}

Java - Decimal Format.parse to return double value with specified number of decimal places

I want to be able to convert a string to a Double given a number of decimal places in a format string. So "###,##0.000" should give me a Double to 3 decimal places.
Edit - added more info to what happens
The user enters the value in the UI - which is input into a String. The rule is this value is limited to 3 decimal places. The underlying code stores the value in the database which is then used in a calculation. Therefore the trailing decimal places will cause the calculations to be out slightly to what would be expected.
I have the following code:
try {
// output current locale we are running under (this happens to be "nl_BE")
System.out.println( "Current Locale is " + Locale.getDefault().toString() );
// number in Central European Format with a format string specified in UK format
String numberCE = "1,234567"; // 1.234567
String formatUK = "###,##0.000";
// do the format
DecimalFormat formatterUK = new DecimalFormat( formatUK );
Double valCEWithUKFormat = formatterUK.parse( numberCE ).doubleValue();
// I want the number to DPs in the format string!!!
System.out.println( "CE Value " + numberCE + " in UK format (" + formatUK + ") is "
+ valCEWithUKFormat );
} catch( ParseException ex ) {
System.out.println("Cannot parse number");
}
}
The DecimalFormat seems to ignore the format string and gives me the complete string as a Double of 1.234567.
Can DecimalFormat be forced to use the format string when parsing? Am I missing something?
Cheers,
Andez

DecimalFormat is used for two distinct purposes: parsing input and formatting output. If you want to do both, you'll have to use the format object twice.
If you want to take that value and format the output, restricting the number of significant digits, you need to use the format object again. This time it uses your formatting rules to create an output string from a numeric value:
String output = formatterUK.format(valCEWithUKFormat.doubleValue() );
This will give you the output of 1,235
It seems you want this numeric value to be presented in the 1.235 format. To do this, you should format the output using a specific locale (if yours uses a different format).
HOWEVER, I would recommend approaching this problem differently:
String text = "1,234567";
NumberFormat nf_in = NumberFormat.getNumberInstance(Locale.GERMANY);
double val = nf_in.parse(text).doubleValue();
NumberFormat nf_out = NumberFormat.getNumberInstance(Locale.UK);
nf_out.setMaximumFractionDigits(3);
String output = nf_out.format(val);
A few notes:
Input parsing should be kept separate from output formatting. Especially when you start throwing in multiple Locales.
Allow the standard library to do the heavy lifting for determining what a valid input value is for a given Locale. You just need to select an appropriate Locale (I chose GERMANY, but this would obviously work with others). Always use Locales when possible. Don't try to recreate formatting strings.
Always store your input value SEPARATE from any output formatting. IE, if you want to show only three digits in the output, that's fine, but store the whole double value anyway.

Taking on board what you said I have modified my code slightly to cover different locales. The key was taking a value string in a localised format to a Double that is rounded based on the format string.
The format string is always a UK based format with the decimal seperators specified as "." and thousand seperators specified as ",".
I am using the DecimalFormat to initially parse the localised format based on a specified locale. This gives a Double equivalent of the string correctly. I then use a BigDecimal to handle the rounding. I can get the number of decimal places from the DecimalFormat instance and call setScale on the BigDecimal to perform the rounding.
The initial code structure has been modified to allow you to see what happens under different locale circumstances thanks #RD01 for noting importance of other locales.
I now have code as follows:
private void runTests3() {
// output current locale we are running under
System.out.println( "Current Locale is " + Locale.getDefault().toString() );
// number in Central European Format with a format string specified in UK format
String numbersInEuropeanFormatString[] = new String[] { "1.000,234567", "1,2345678", "1.222.333,234567" };
String formatUK = "###,##0.0000";
// output numbers using the german locale
System.out.println("Output numbers using the German locale\n");
for(String num : numbersInEuropeanFormatString ) {
formatNumberAsDouble(num, formatUK, Locale.GERMAN);
}
// output numbers using the UK locale.
// this should return unexpected results as the number is in European format
System.out.println("Output numbers using the UK locale\n");
for(String num : numbersInEuropeanFormatString ) {
formatNumberAsDouble(num, formatUK, Locale.UK);
}
// output numbers using new DecimalFormat( formatUK ) - no locale specified
System.out.println("\n\nOutput numbers using new DecimalFormat( " + formatUK + " )\n");
for(String num : numbersInEuropeanFormatString ) {
formatNumberAsDouble( num, formatUK, null);
}
}
private void formatNumberAsDouble(String value, String format, Locale locale) {
NumberFormat formatter;
int decimalPlaces;
// create the formatter based on the specified locale
if( locale != null ) {
formatter = NumberFormat.getNumberInstance(locale);
// creating the above number format does not take in the format string
// so create a new one that we won't use at all just to get the
// decimal places in it
decimalPlaces = (new DecimalFormat(format)).getMaximumFractionDigits();
} else {
formatter = new DecimalFormat( format );
decimalPlaces = formatter.getMaximumFractionDigits();
}
// get the result as number
Double result = null;
try {
result = formatter.parse( value ).doubleValue();
} catch( ParseException ex ) {
// not bothered at minute
}
// round the Double to the precision specified in the format string
BigDecimal bd = new BigDecimal(result );
Double roundedValue = bd.setScale( decimalPlaces, RoundingMode.HALF_UP ).doubleValue();
// output summary
System.out.println("\tValue = " + value);
System.out.println( locale == null ? "\tLocale not specified" : "\tLocale = " + locale.toString());
System.out.println( format == null || format.length() == 0 ? "\tFormat = Not specified" : "\tFormat = " + format);
System.out.println("\tResult (Double) = " + result);
System.out.println("\tRounded Result (Double) (" + decimalPlaces + "dp) = " + roundedValue);
System.out.println("");
}
This produces the following output:
Current Locale is nl_BE
Output numbers using the German locale
Value = 1.000,234567
Locale = de
Format = ###,##0.0000
Result (Double) = 1000.234567
Rounded Result (Double) (4dp) = 1000.2346
Value = 1,2345678
Locale = de
Format = ###,##0.0000
Result (Double) = 1.2345678
Rounded Result (Double) (4dp) = 1.2346
Value = 1.222.333,234567
Locale = de
Format = ###,##0.0000
Result (Double) = 1222333.234567
Rounded Result (Double) (4dp) = 1222333.2346
Output numbers using the UK locale
Value = 1.000,234567
Locale = en_GB
Format = ###,##0.0000
Result (Double) = 1.0
Rounded Result (Double) (4dp) = 1.0
Value = 1,2345678
Locale = en_GB
Format = ###,##0.0000
Result (Double) = 1.2345678E7
Rounded Result (Double) (4dp) = 1.2345678E7
Value = 1.222.333,234567
Locale = en_GB
Format = ###,##0.0000
Result (Double) = 1.222
Rounded Result (Double) (4dp) = 1.222
Output numbers using new DecimalFormat( ###,##0.0000 )
Value = 1.000,234567
Locale not specified
Format = ###,##0.0000
Result (Double) = 1000.234567
Rounded Result (Double) (4dp) = 1000.2346
Value = 1,2345678
Locale not specified
Format = ###,##0.0000
Result (Double) = 1.2345678
Rounded Result (Double) (4dp) = 1.2346
Value = 1.222.333,234567
Locale not specified
Format = ###,##0.0000
Result (Double) = 1222333.234567
Rounded Result (Double) (4dp) = 1222333.2346

The restriction of decimal places in DecimalFormat is really meant for use in the format() method and doesn't have much effect in the parse() method.
In order to get what you want you need this:
try {
// output current locale we are running under (this happens to be "nl_BE")
System.out.println("Current Locale is " + Locale.getDefault().toString());
// number in Central European Format with a format string specified in UK format
String numberCE = "1,234567"; // 1.234567
String formatUK = "###,##0.000";
// do the format
DecimalFormat formatterUK = new DecimalFormat(formatUK);
Double valCEWithUKFormat = formatterUK.parse(numberCE).doubleValue();
// first convert to UK format string
String numberUK = formatterUK.format(valCEWithUKFormat);
// now parse that string to a double
valCEWithUKFormat = formatterUK.parse(numberUK).doubleValue();
// I want the number to DPs in the format string!!!
System.out.println("CE Value " + numberCE + " in UK format (" + formatUK + ") is " + valCEWithUKFormat);
} catch (ParseException ex) {
System.out.println("Cannot parse number");
}
You first need to get the number as a UK format string and then parse that number, using the UK formatter. That will get you the result you're looking for. NB, this will round the number to 3 decimal places, not truncate.
By the way, I'm slightly surprised that your UK formatter is able to parse the CE format number. You really should be parsing the original number with a CE format parser.

Sure you can. Try running this:
String in = "1,234567";
System.out.println(NumberFormat.getNumberFormat(new Locale("fr", "FR")).parse(in));
System.out.println(NumberFormat.getNumberFormat(new Locale("en", "GB")).parse(in));
Clearly they result in different output, the first reading 1.234567 and the second 1234567. Maybe there's something wrong with your pattern? Anyway the last line there would be the preferred way of getting the UK standard format.