Java正则表达式模式匹配

Question

I want to create a regular expression, in Java, that will match the following:

*A*B

where A and B are ANY character except asterisk, and there can be any number of A characters and B characters. A(s) is/are preceded by asterisk, and B(s) is/are preceded by asterisk.

Will the following work? Seems to work when I run it, but I want to be absolutely sure.

Pattern.matches("\\A\\*([^\\*]{1,})\\*([^\\*]{1,})\\Z", someString)

Answer 1

It will work, however you can rewrite it as this (unquoted):

\A\*([^*]+)\*([^*]+)\Z

• there is no need to quote the star in a character class;
• {1,} and + are the same quantifier (once or more).

Note 1: you use .matches() which automatically anchors the regex at the beginning and end; you may therefore do without \\A and \\Z .

Note 2: I have retained the capturing groups -- do you actually need them?

Note 3: it is unclear whether you want the same character repeated between the stars; the example above assumes not. If you want the same, then use this:

\A\*(([^*])\2*)\*(([^*])\4*)\Z

Answer 2

如果我正确的话..它可以很简单

^\\*((?!\\*).)+\\*((?!\\*).)+

Answer 3

If you want a match on *AAA*BBB but not on *ABC*DEF use

^\*([a-zA-Z])\1*\*([a-zA-Z])\2*$

This won't match on this either

*A_$-123*B<>+-321