字符串中的Java正则表达式

Question

<InstanceIdentifier>118e3040-51d2-11e3-8f96-1110200c9a66</InstanceIdentifier>

This is my string, and i want the 118e3040-51d2-11e3-8f96-1110200c9a66 part.

tried this

Pattern p = Pattern.compile("(\\b<InstanceIdentifier>\\b)(.*?)(\\b<\/InstanceIdentifier>\\b)");

but of course it's not working. Suggestions?

Answer 1

Just remove the first and last \\\\b then remove the backslash which exists before /

Pattern p = Pattern.compile("(<InstanceIdentifier>\\b)(.*?)(\\b</InstanceIdentifier>)");

or

Pattern p = Pattern.compile("<InstanceIdentifier>\\b(.*?)\\b</InstanceIdentifier>");
Matcher m = p.matcher(s);
if(m.find())
{
System.out.println(m.group(1));
}

Note that \\\\b matches between a word character and a non-word character, so the above regex must except a word character next to the starting INstanceIdentifier tag and before the closing INstanceIdentifier tag.

Your regex fails because there isn't a word character character which actually exists between the start of the line and the opening < bracket , likewise there isn't a word character which exists next to > and end of the line boundary. In this case, adding \\\\B instead of \\\\b at the start and end should work.