list.stream的常见使用

最新推荐文章于 2025-09-06 10:09:53 发布

原创最新推荐文章于 2025-09-06 10:09:53 发布 · 308 阅读

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public static void main(String[] args) {
   List<Student> list = Lists.newArrayList();
   list.add(new Student("id1", "张三", "男", 18));
   list.add(new Student("id2", "李四", "男", 20));
   list.add(new Student("id3", "王五", "女", 19));
   list.add(new Student("id4", "赵六", "女", 22));

   //获取id的集合
   List<String> idList = list.stream().map(Student::getId()).collect(Collectors.toList());

//过滤
List<Student> l1 = list.stream().filter(student -> student.getSex().equals("男")).collect(toList());

   //获取map
   Map<String, String> map = list.stream().collect(Collectors.toMap(Student::getId(), Student::getName()));

   //是否存在
   boolean isExist = list.stream().anyMatch(item -> item.getId().equals("id1"));

}

注：
.collect(toList()) 可以写成 .collect(Collectors.toList());