Java multi-line regular expression debugging

Question

In Java, the following regular expression

To: a@b\.com.*Subject: Please verify your email address

somehow doesn't find the match in this text:

Dez 21, 2012 10:29:58 AM com.google.appengine.api.datastore.dev.LocalDatastoreService init
INFO: Local Datastore initialized: 
    Type: High Replication
    Storage: In-memory
Dez 21, 2012 10:29:58 AM com.google.appengine.api.mail.dev.LocalMailService log
INFO: MailService.send
Dez 21, 2012 10:29:58 AM com.google.appengine.api.mail.dev.LocalMailService log
INFO:   From: 
Dez 21, 2012 10:29:58 AM com.google.appengine.api.mail.dev.LocalMailService log
INFO:   To: a@b.com
Dez 21, 2012 10:29:58 AM com.google.appengine.api.mail.dev.LocalMailService log
INFO:   Subject: Please verify your email address
Dez 21, 2012 10:29:58 AM com.google.appengine.api.mail.dev.LocalMailService log
INFO:   Body:
Dez 21, 2012 10:29:58 AM com.google.appengine.api.mail.dev.LocalMailService log
INFO:     Content-type: text/plain
Dez 21, 2012 10:29:58 AM com.google.appengine.api.mail.dev.LocalMailService log
INFO:     Data length: 4

My Java code looks like this:

    Matcher matcher = Pattern.compile(regex, Pattern.MULTILINE).matcher(input);
    if (matcher.find()) {
        ...
    }

This is a bit strange, since the pattern seems to work when I test it online with this tool: http://regexpal.com

So, Java must be interpreting the pattern a bit differently. Is there any way to get error messages of the Matcher ?

Update It should find:

To: a@b.com
Dez 21, 2012 10:29:58 AM com.google.appengine.api.mail.dev.LocalMailService log
INFO:   Subject: Please verify your email address

Answer 1

You'll want to use Pattern.DOTALL instead of Pattern.MULTILINE .

DOTALL makes the . match newlines. (Which is what you want)

MULTILINE makes ^ and $ work on a per-line basis.