java - Error in Regular expression for find File according a Pattern -

java - Error in Regular expression for find File according a Pattern -

i need develop pattern in regular expression:

pattern:

201410021600(12 numbers)-only 2 options or b_(zz same)616048(6 numbers)_bbbb(4 characters)-123456abcdef(12 alfanumeric)_out(always same).pdf(always same)

real example:

201410021600-a_zz123456_bbbb-123456abcdef_out.pdf.

this attempt, didn,t work :(:

\d{12}-{1}a_{1}\bzz\b\d{6}_{1}\d{4}-{1}\w{12}_{1}\bout.pdf\b

somebody can help me, please?

you don't need specify quantity 1, i.e. instead of -{1} or _{1} - or _ sufficient.

additionally, you're specifying quantity twice here: \d{6}{1} not necessary.

third, \b marks word boundary means there needs @ to the lowest degree whitespace. \bzz\b won't match input.

applying this, regex looks , should work: \d{12}-[ab]_zz\d{6}_[a-z]{4}-[a-z0-9]{12}_out\.pdf

to break down:

201410021600(12 numbers) -> \d{12} -only 2 options or b -> -[ab] update: comment seems if a , b words , not characters, can't utilize character class here need utilize grouping instead, e.g. -(?>a|b) ((?>...) means grouping non-capturing, i.e. can't retrieve using matcher.group(x) etc.) _(zz same) -> _zz 616048(6 numbers)-> \d{6} _bbbb(4 characters) -> _[a-z]{4} (i assume upper case chars allowed) -123456abcdef(12 alfanumeric) -> -[a-z0-9]{12} (in case upper case characters allowed) _out(always same) - > _out .pdf(always same) -> \.pdf (the dot matches character needs escaped)

if case not matter, i.e. if 201410021600-a_zz123456_bbbb-123456abcdef_out.pdf. should match well, either add together a-z character classes should allow lower case (e.g. [a-za-z] instead of [a-z]) or add together (?i) @ front end of look if lower case allowed.

java regex