guava Splitter 学习

  @Test
  public void Str2ListGuava(){
        String str = "1,2,3,4,5,6,7,8,30,,";
        // 用逗号切割并转为对象
        List<String> list1 = Splitter.on(',').splitToList(str);
        //去除空对象并转为其他类型
        List<Integer> list2 = Splitter.on(',').omitEmptyStrings().splitToList(str).stream().map(Integer::parseInt).collect(Collectors.toList());
        System.out.println("结果：" + list1);
        System.out.println("结果：" + list2);
    }

guava Sets 集合类取交集、差集、并集

 public static void main(String[] args) {
        List<Integer> list1 = Lists.newArrayList(1, 2, 3, 4, 5, 6);
        List<Integer> list2 = Lists.newArrayList(3, 4, 5, 6, 7, 8, 9);

        // 交集
        System.out.println("交集为：");
        Sets.SetView<Integer> intersection = Sets.intersection(Sets.newHashSet(list1), Sets.newHashSet(list2));

        // 差集
        System.out.println("差集为：");
        Sets.SetView<Integer> diff = Sets.difference(Sets.newHashSet(list1), Sets.newHashSet(list2));
 
        // 并集
        System.out.println("并集为：");
        Sets.SetView<Integer> union = Sets.union(Sets.newHashSet(list1), Sets.newHashSet(list2));
        // 取并集并转为List
        List<Integer> integers = Lists.newArrayList(union);
    }