java8新特性 获取list某一列的操作

//从对象列表中提取一列(以name为例)
List<String> nameList = studentList.stream().map(StudentInfo::getName).collect(Collectors.toList());
//提取后输出name
nameList.forEach(s-> System.out.println(s));

List<Category> categoryList = CategoryService.fiall();

List<Integer> categoryTypeList = categoryList.stream().map(e -> e.getCategoryType()).collect(Collectors.toList());