public static String[] split(String str) {
        return split(str, null, -1);
    }
<p>Splits the provided text into an array, using whitespace as the
separator.
Whitespace is defined by {@link Character#isWhitespace(char)}.</p>

<p>The separator is not included in the returned String array.
Adjacent separators are treated as one separator.
For more control over the split use the StrTokenizer class.</p>

<p>A {@code null} input String returns {@code null}.</p>

<pre>
StringUtils.split(null)       = null
StringUtils.split("")         = []
StringUtils.split("abc def")  = ["abc", "def"]
StringUtils.split("abc  def") = ["abc", "def"]
StringUtils.split(" abc ")    = ["abc"]
</pre>

@param str  the String to parse, may be null
@return an array of parsed Strings, {@code null} if null String input
android/android_framework/base/src/main/java/lang3/StringUtils.java