Java Regular Expressions

External

• http://docs.oracle.com/javase/8/docs/api/java/util/regex/Pattern.html#sum

Internal

• java
• Regular Expressions

Overview

Regular expressions can be used in Java via the String API or java.util.regex API.

java.util.regex API

The common approach for using regular expressions consists in building a Pattern instance, which can be matched against multiple strings by applying it via Matcher instances. The Matcher instances are not thread safe, see Concurrent Usage Consideratins below.

Working code is available here:

https://github.com/NovaOrdis/playground/tree/master/java/regex/simplest

java.langString API

String s = "...";
s.matches(...);

While convenient in some cases, the String API also delegates to the java.util.regex API via the Pattern.matches() call.

Concurrent Usage Considerations

Matcher instances are NOT thread safe, create a matcher per thread