Stream流实现Object与map相互转化

可以通过Java 8中的Stream API实现Object与Map相互转换，具体步骤如下：

将Object转换为Map：

1. 首先需要获取该Object的所有字段，可以通过反射实现，如下：

Field[] fields = obj.getClass().getDeclaredFields();

2. 然后通过Stream将字段转换为Map，如下：

Map<String, Object> map = Arrays.stream(fields)
    .peek(field -> field.setAccessible(true))
    .collect(Collectors.toMap(Field::getName, field -> {
        try {
            return field.get(obj);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
        return null;
    }));

将Map转换为Object：

1. 首先需要获取该Object的Class对象，如下：

Class clazz = obj.getClass();

2. 然后通过Stream将Map中的键值对转换为Object的字段，如下：

map.forEach((key, value) -> {
    try {
        Field field = clazz.getDeclaredField(key);
        field.setAccessible(true);
        field.set(obj, value);
    } catch (NoSuchFieldException | IllegalAccessException e) {
        e.printStackTrace();
    }
});

完整代码如下：

import java.lang.reflect.Field;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.stream.Collectors;

public class ObjectMapConverter {
    public static Map<String, Object> objectToMap(Object obj) {
        Field[] fields = obj.getClass().getDeclaredFields();
        Map<String, Object> map = Arrays.stream(fields)
                .peek(field -> field.setAccessible(true))
                .collect(Collectors.toMap(Field::getName, field -> {
                    try {
                        return field.get(obj);
                    } catch (IllegalAccessException e) {
                        e.printStackTrace();
                    }
                    return null;
                }));
        return map;
    }

    public static void mapToObject(Map<String, Object> map, Object obj) {
        Class clazz = obj.getClass();
        map.forEach((key, value) -> {
            try {
                Field field = clazz.getDeclaredField(key);
                field.setAccessible(true);
                field.set(obj, value);
            } catch (NoSuchFieldException | IllegalAccessException e) {
                e.printStackTrace();
            }
        });
    }

    public static void main(String[] args) {
        Person person = new Person("Tom", 20);
        Map<String, Object> map = objectToMap(person);
        System.out.println(map);

        Person newPerson = new Person();
        mapToObject(map, newPerson);
        System.out.println(newPerson);
    }
}

class Person {
    private String name;
    private int age;

    public Person() {}

    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    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;
    }

    @Override
    public String toString() {
        return "Person{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}