如果它是java对象的集合，则可以实现 Comparable 用于计算 .sort() 对象的名称。
不过幸运的是，streamapi已经有了一些有用的内置方法以及comparator。
例如，对于你的字符串，我写了：

@Test
@DisplayName("Sort Array of Strings with Nulls First or Last")
void sorty(){

    final String[] unsortedArray = {"Bob",null,"Alice",null,"Charlie","Emma",null,null,"Dave"};

    //To List with Stream, Sort using Comparator but with nulls first then collect to String list.
    final List<String> sortedArray = Arrays.stream(unsortedArray)
                .sorted(Comparator.nullsFirst(String::compareToIgnoreCase))
                .collect(Collectors.toList());

    //Assertions
    String[] expectedResult = {null,null,null,null,"Alice","Bob","Charlie","Dave","Emma"};
    Assertions.assertEquals(Arrays.asList(expectedResult),sortedArray);
    Assertions.assertNotEquals(Arrays.asList(unsortedArray),sortedArray);

    //Or using nullsLast:

    //To List with Stream, Sort using Comparator but with nulls last then collect to String list.
    final List<String> sortedArrayNullsLast = Arrays.stream(unsortedArray)
                .sorted(Comparator.nullsLast(String::compareToIgnoreCase))
                .collect(Collectors.toList());

    //Assertions
    String[] expectedResultNullsLast = {"Alice","Bob","Charlie","Dave","Emma",null,null,null,null};
        Assertions.assertEquals(Arrays.asList(expectedResultNullsLast),sortedArrayNullsLast);
        Assertions.assertNotEquals(Arrays.asList(unsortedArray),sortedArrayNullsLast);

    //PS: You can instead of Collect to List of Strings in the Stream to an array instead...

    //To List with Stream, Sort using Comparator but with nulls last then collect to String list. I just did
    // to list to compare them in the assertion tests.
    final String[] sortedArrayNullsLastAsArray = Arrays.stream(unsortedArray)
                .sorted(Comparator.nullsLast(String::compareToIgnoreCase))
                .toArray(String[]::new);
    }