标签：color lam print ase lse compare toc vat int
* map—接收Lambda，将元素转换成其他形式或提取信息。接收一个函数作为参数，该函数会被应用到每个元素上，并将其映射成一个新的元素。
* FlatMap—接收一个函数作为参数，将流中的每个值都换成另一个流，然后把所有流连接成一个流
List<Employee> employees = Arrays.asList(// new Employee(20, "张三", 5000.35), // new Employee(40, "李四", 6500.63), // new Employee(30, "王五", 4000.93), // new Employee(50, "赵六", 9005.36), // new Employee(10, "马七", 1050.93), // new Employee(10, "马七", 1050.93), // new Employee(10, "马七", 1050.93), // new Employee(10, "马七", 1050.93), // new Employee(20, "朱八", 3000.73)// );
1、map—接收Lambda，FlatMap—接收一个函数作为参数
@Test public void test5() { List<String> asList = Arrays.asList("aaa", "bbb", "ccc", "ddd", "eee", "fff"); asList.stream().map((e) -> e.toUpperCase()).forEach(System.out::println); System.out.println("===================="); employees.stream().map(Employee::getName).forEach(System.out::println); System.out.println("===================="); Stream<Stream<Character>> map = asList.stream().map(StreamApiTest2::filterCharacter); map.forEach((e) -> { e.forEach(System.out::println); }); System.out.println("===================="); asList.stream().flatMap(StreamApiTest2::filterCharacter).forEach(System.out::println); } private static Stream<Character> filterCharacter(String str) { List<Character> list = new ArrayList<Character>(); char[] charArray = str.toCharArray(); for (char c : charArray) { list.add(c); } return list.stream(); }
2、排序 sorted（）—自然排序 sorted（Comparator com)一定制排序
@Test public void test6() { List<String> asList = Arrays.asList("aaa", "bbb", "ccc", "ddd", "eee", "fff"); asList.stream().sorted().forEach(System.out::println); System.out.println("===================="); employees.stream().sorted((e1, e2) -> { if (e1.getAge().equals(e2.getAge())) { return e1.getName().compareTo(e2.getName()); } else { return -e1.getAge().compareTo(e2.getAge()); } }).forEach(System.out::println); }
标签：color lam print ase lse compare toc vat int
原文地址：https://www.cnblogs.com/zhanh247/p/11854442.html
