我有一个字符串集合，我想将其转换为全部为空或为null的字符串集合，并删除所有字符串，并修剪所有其他字符串。

我可以分两步来做：

final List<String> tokens =
    Lists.newArrayList(" some ", null, "stuff\t", "", " \nhere");
final Collection<String> filtered =
    Collections2.filter(
        Collections2.transform(tokens, new Function<String, String>(){

            // This is a substitute for StringUtils.stripToEmpty()
            // why doesn't Guava have stuff like that?
            @Override
            public String apply(final String input){
                return input == null ? "" : input.trim();
            }
        }), new Predicate<String>(){

            @Override
            public boolean apply(final String input){
                return !Strings.isNullOrEmpty(input);
            }

        });
System.out.println(filtered);
// Output, as desired: [some, stuff, here]

但是，是否有番石榴方法将两个动作组合为一个步骤？