实体类

package po;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.io.Serializable;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Student implements Serializable {

    /**
     * 姓名
     */
    private String name;

    /**
     * 地址
     */
    private Address address;
}

package po;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@AllArgsConstructor
@Data
@NoArgsConstructor
public class Address {

    /**
     * 城市
     */
    private String city;
}

Optional对非空对象的处理

满足过滤条件返回的值

package com.demo;

import po.Address;
import po.Student;

import java.util.Optional;

public class TestCase3 {
    public static void main(String[] args) {
        Student student = new Student("张三", new Address("香港"));
        Student student1 = Optional.ofNullable(student)
                .filter(s -> "张三1".equals(s.getName()))
                .orElseGet(() -> new Student("李四", new Address("北京")));
        System.out.println(student1);
    }
}

不满足条件返回的值

package com.demo;

import po.Address;
import po.Student;

import java.util.Optional;

public class TestCase3 {
    public static void main(String[] args) {
        Student student = new Student("张三", new Address("香港"));
        Student student1 = Optional.ofNullable(student)
                .filter(s -> "张三".equals(s.getName()))
                .orElseGet(() -> new Student("李四", new Address("北京")));
        System.out.println(student1);
    }
}