ArrayList filter

In java-8, they introduced the method removeIf which takes a Predicate as parameter.

So it will be easy as:

List<String> list = new ArrayList<>(Arrays.asList("How are you",
                                                  "How you doing",
                                                  "Joe",
                                                  "Mike"));
list.removeIf(s -> !s.contains("How"));

Probably the best way is to use Guava

List<String> list = new ArrayList<String>();
list.add("How are you");
list.add("How you doing");
list.add("Joe");
list.add("Mike");
    
Collection<String> filtered = Collections2.filter(list,
    Predicates.containsPattern("How"));
print(filtered);

prints

How are you
How you doing

In case you want to get the filtered collection as a list, you can use this (also from Guava):

List<String> filteredList = Lists.newArrayList(Collections2.filter(
    list, Predicates.containsPattern("How")));