I need to replace all special control character in a string in Java.
I want to ask the Google maps API v3, and Google doesn't seems to like these characters.
Example: http://www.google.com/maps/api/geocode/json?sensor=false&address=NEW%20YORK%C2%8F
This URL contains this character: http://www.fileformat.info/info/unicode/char/008f/index.htm
So I receive some data, and I need to geocode this data. I know some character would not pass the geocoding, but I don't know the exact list.
I was not able to find any documentation about this issue, so I think the list of characters that Google doesn't like is this one: http://www.fileformat.info/info/unicode/category/Cc/list.htm
Is there any already built function to get rid of these characters, or do I have to build a new one, with a replace one by one?
Or is there a good regexp to do the job done?
And does somebody know which exact list of characters Google doesn't like?
Edit : Google have create a webpage for this :
https://developers.google.com/maps/documentation/webservices/?hl=fr#BuildingURLs
If you want to delete all characters in Other/Control Unicode category, you can do something like this:
System.out.println(
"a\u0000b\u0007c\u008fd".replaceAll("\\p{Cc}", "")
); // abcd
Note that this actually removes (among others) '\u008f'
Unicode character from the string, not the escaped form "%8F"
string.
If the blacklist is not nicely captured by one Unicode block/category, Java does have a powerful character class arithmetics featuring intersection, subtraction, etc that you can use. Alternatively you can also use a negated whitelist approach, i.e. instead of explicitly specifying what characters are illegal, you specify what are legal, and everything else then becomes illegal.
Here's a subtraction example:
System.out.println(
"regular expressions: now you have two problems!!"
.replaceAll("[a-z&&[^aeiou]]", "_")
);
// _e_u_a_ e___e__io__: _o_ _ou _a_e __o __o__e__!!
The […]
is a character class. Something like [aeiou]
matches one of any of the lowercase vowels. [^…]
is a negated character class. [^aeiou]
matches one of anything but the lowercase vowels.
[a-z&&[^aeiou]]
matches [a-z]
subtracted by [aeiou]
, i.e. all lowercase consonants.
The next example shows the negated whitelist approach:
System.out.println(
"regular expressions: now you have two problems!!"
.replaceAll("[^a-z]", "_")
);
// regular_expressions__now_you_have_two_problems__
Only lowercase letters a-z
are legal; everything else is illegal.