### Question:
StringUtil { public static int[] splitAsIntArray(String str, String delimiter) { if (str == null) return null; String[] strs = str.split(delimiter); int[] result = new int[strs.length]; for (int i = 0; i < strs.length; i++) result[i] = Integer.valueOf(strs[i]); return result; }  static boolean isEmpty(String str); static String getLeft(String src, int length); static String getRight(String src, int length); static boolean isDigitOnly(String chkStr); static String SQLEscape(String str); static String fillString(String str, int length, char fillChar, boolean fillLeft); static String cEscape(String str); static String cEscape(String str, char quoteChar); static String cEscape(String str, char quoteChar, boolean isWchar); static String lowerFirst(String str); static String upperFirst(String str); static boolean isJavaIdentifier(String str); static int[] splitAsIntArray(String str, String delimiter); static String join(byte[] items, String delimiter); static String join(String[] items, String delimiter); static String join(List<String> items, String delimiter); static StringBuilder appendRepeatedly(StringBuilder result, String str, int times); static StringBuilder appendRepeatedly(StringBuilder result, char c, int times); static String toTrimmedStr(Object o, int len);  }### Answer:
@Test public void testSplitAsIntArray() { assertArrayEquals(new int[]{1,2,3}, StringUtil.splitAsIntArray("1,2,3", ",")); assertNull(StringUtil.splitAsIntArray(null, ",")); }