How to write regex pattern in lucene?

Question

I want to match a string from regexp query in lucene.

Test String:

       program-id.  acinstal.

Regex pattern in java:

^[a-z0-9 ]{6}[^*]\s*(program-id)\.

How would i write this regex specifically for lucene regexp query to match the string.

Solution

Two problems with your regex (assuming here, based on previous questions, that your test string is indexed without any tokenization. As a StringField, for instance):

1. The regex must match a whole term. Without any analysis, as we're assuming, that means it must match the whole field. In this case, you need to add a .* to match the rest of the field

2. Since you have to match the whole field anyway, anchors are not supported, so get rid of the ^ at the beginning.

So the regex that should work is:

[a-z0-9 ]{6}[^*]\s*(program-id)\..*

Comments

[rocky]

Is there any way to run multiple regex in lucene by grouping them with AND OR operators.

[femtoRgon]

@rocky - Yes, you can combine multiple queries with BooleanQuery.

[rocky]

[A-Z0-9 ]{6}[^*]\senvironment\s+division\.. its not working, can you please tell me what's wrong with this pattern??

[femtoRgon]

The \s escape sequence is not supported. See the docs for what regex syntax is available in lucene.