named-regexp

about

named-regexp backports named capture groups from Java 7 to Java 5/6

usage

named groups

To create a named capture group, use (?<name>...), as in:

Pattern p = Pattern.compile("abc(?<foo>\\d+)xyz");
Matcher m = p.matcher("abc123xyz");
System.out.println(m.find());       // true
System.out.println(m.group("foo")); // 123

back references

To back-reference a named group in a pattern, use \k<name>, as in:

Pattern p = Pattern.compile("abc(?<foo>\\d+)def\\k<foo>");
Matcher m1 = p.matcher("abc123def123ghi");
Matcher m2 = p.matcher("abc123def456ghi");
System.out.println(m1.find());       // true
System.out.println(m1.group("foo")); // 123
System.out.println(m2.find());       // false

replacement references

To reference a named group for string replacement, use ${name}, as in:

Pattern p = Pattern.compile("abc(?<foo>\\d+)def");
Matcher m = p.matcher("abc123def");
System.out.println(m.replaceAll("${foo}456 ${foo}")); // 123456 123

download

Maven dependency:

<dependency>
  <groupId>com.github.tony19</groupId>
  <artifactId>named-regexp</artifactId>
  <version>1.0.0</version>
</dependency>

docs

Check out the javadocs

(?<named>regexp+)