没有循环的正则表达式

Question

How can I rewrite the following expression without using a loop?

Pattern pattern = Pattern.compile(filterRegEx);
Matcher regexMatcher = pattern.matcher("(.*)");

for (String word : words) {
    if (pattern.matcher(word).matches()) {
        foundList.add(word);
    }
}

Answer 1

You'll need to use some form of functional programming if you want to avoid using a loop. Java 8 will have some new features in this area, but right now you can use the Collections2#filter (or Iterables#filter ) method from Google Guava; it lets you specify a condition (such as pattern.matcher(word).matches() ) and selects the elements in the collection that match.

Note that the object returned "read through" to the original collection, so you'd need to make a copy of them (such as with ArrayList(Collection) ) if you need to keep the filtered list around.