com.github.fge.jsonschema.core.util

Class RegexECMA262Helper

java.lang.Object

com.github.fge.jsonschema.core.util.RegexECMA262Helper

@ThreadSafe
public final class RegexECMA262Helper
extends Object

ECMA 262 validation helper. A script engine is used instead of java.util.regex because the latter doesn't comply with ECMA 262:

• ECMA 262 doesn't have Pattern.DOTALL;
• ECMA 262 doesn't have "possessive" quantifiers (++, ?+, etc);
• there is only one word delimiter in ECMA 262, which is \b; \< (for beginning of word) and \> (for end of word) are not understood.

And many, many other things. See here for the full story. And if you don't yet have Jeffrey Friedl's "Mastering regular expressions", just buy it :p

As script engine is used either Nashorn or Rhino as its fallback. Nashorn is only available on Java 8 runtimes or higher.

Rhino is only the fallback as it is tremendously slower.

Method Summary

Modifier and Type	Method and Description
static boolean	regexIsValid(String regex) Validate that a regex is correct
static boolean	regMatch(String regex, String input) Matches an input against a given regex, in the real sense of matching, that is, the regex can match anywhere in the input.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

regexIsValid

public static boolean regexIsValid(String regex)

Validate that a regex is correct

Parameters:

regex - the regex to validate

Returns:

true if the regex is valid

regMatch

public static boolean regMatch(String regex,
                               String input)

Matches an input against a given regex, in the real sense of matching, that is, the regex can match anywhere in the input. Java's java.util.regex makes the unfortunate mistake to make people believe that matching is done on the whole input... Which is not true.

Also note that the regex MUST have been validated at this point (using regexIsValid(String)).

Parameters:

regex - the regex to use

input - the input to match against (and again, see description)

Returns:

true if the regex matches the input