I've to create a java regex that disable creation of databases. (I'm following these restrictions: http://dev.mysql.com/doc/refman/5.0/en/identifiers.html)
Can anyone help me to build a regex with this restriction [0-9,a-z,A-Z$_] ?
This is my snippet:
Pattern pattern = Pattern.compile("[0-9a-zA-Z$_]");
Matcher matcher = pattern.matcher("userdatabase");
System.out.println(matcher.matches());
You didn't specify a quantifier. Your expression will only match one character.
Try changing it to:
Pattern pattern = Pattern.compile("[0-9a-zA-Z$_]+");
The + indicates that it should be that expressions 1 or more times.
[0-9a-zA-Z$_], so it won't accept "The user"If you mean regex for 0-9a-zA-Z$_ it is simple:
String string = "the input";
String regularExpression = "^[0-9a-zA-Z$_]+$";
Pattern pattern = Pattern.compile(regularExpression);
Matcher matcher = pattern.matcher(string);
System.out.println(matcher.matches());
If you mean that you don't want to execute "CREATE TABLE" commands then you can check something like this:
String regularExpression = ".*create\stable.*";
Pattern pattern = Pattern.compile(regularExpression, Pattern.CASE_INSENSITIVE);
i read out of the context you want to avoid SQL injection? if yes, you could simply use prepared statements instead of sql strings.
