JDK1.8新特性中的lambda表达式(不全)

1.8新特性（全）文章地址：https://blog.csdn.net/qq_29411737/article/details/80835658

package reflect;

/**
 * @author fkl
 * @date 2020/12/22 14:15
 **/

public class User {

    private int id;
    private String name;
    private int age;
    private String address;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public User(int id, String name, int age, String address){
        this.id = id;
        this.name = name;
        this.age = age;
        this.address = address;
    }
}

package reflect;

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

/**
 * @author fkl
 * @date 2020/12/22 14:27
 **/
public class UserTest {
    public static void main(String[] args) {

        List<User> userList = new ArrayList<>();

        User u1 = new User(1, "u1", 23, "特使1");
        User u2 = new User(2, "u2", 24, "特使2");
        User u3 = new User(3, "u3", 25, "特使3");
        User u4 = new User(4, "u4", 26, "特使4");
        User u5 = new User(5, "u5", 22, "特使5");
        User u6 = new User(6, "u6", 23, "特使6");

        userList.add(u1);
        userList.add(u2);
        userList.add(u3);
        userList.add(u4);
        userList.add(u5);
        userList.add(u6);

        /**使用lambda表达式截取List中的某一个属性的值*/
        System.out.println("使用lambda表达式截取List中的某一个属性的值");
        List<Integer> ids = userList.stream().map(e -> e.getId()).collect(Collectors.toList());
        System.out.println("取出某一属性的结果值为：" + ids);


        System.out.println("《《《《《《《《《《》》》》》》》》");

        System.out.println("使用lambda表达式遍历循环List");
        userList.stream().forEach(user -> {
            System.out.println("user值："+user.getId()+"," + user.getName()+","+user.getAge()+","+user.getAddress());
        });

        System.out.println("《《《《《《《《《《》》》》》》》》");
/*
        System.out.println("使用lambda表达式过滤某一个属性的值");
        System.out.println("过滤前userList的值:" + userList);
        userList = userList.stream().filter(s -> s.getAge() > 24).collect(Collectors.toList());
        System.out.println("过滤后userList的值:"+userList);*/
    }
}