Java Decimal Format parsing issue

You can use

 String num = "1 201";
 DecimalFormat df = (DecimalFormat) NumberFormat.getNumberInstance(Locale.FRANCE);
 System.out.println("Number Before parse: "+num);   

 DecimalFormatSymbols symbols = df.getDecimalFormatSymbols();
 symbols.setGroupingSeparator(' ');
 df.setDecimalFormatSymbols(symbols);

 double  dm = df.parse(num).doubleValue();
 System.out.println("Number After parse: "+dm);  

Expected Output:

Number Before parse: 1 201
Number After parse:  1201.0

Actually, Java is using the character unbreakable space (\u00a0) to parse French numbers.

Thus, the following code actually works:

String num = "1\u00a0201";
double dm = df.parse(num).doubleValue();
System.out.println("Number After parse: " + dm);

---

See @ParkerHalo answer which provide more details.

There are two kinds of spaces. The "normal" space character (No. 32 - HEX 0x20) and the non-breaking space (NBSP) (No. 160 - HEX 0xA0).

The French locale expects the whitespace character between the digits to be the non breaking space! You can help yourself with this line of code:

String num = "1 201";
num = num.replaceAll(" ", "\u00A0");    // '\u00A0' is the non breaking whitespace character!

This way your code will work like expected. Please note that if you format a double into a String with French locale the resulting whitespace character will be the NBSP too!!!

DecimalFormat df = (DecimalFormat) NumberFormat.getNumberInstance(Locale.FRENCH);
System.out.println(df.format(1201.1));
// This will print "1 202,1" But the space character will be '\u00A0'!