Java浅拷贝与深拷贝-优快云博客

浅拷贝与深拷贝是对象复制的两种方式；

浅拷贝

定义

创建一个新的对象，基础数据类型属性复制值，引用数据类型属性复制引用地址（共享一个实例）

特点

当修改原数据的引用数据类型属性的值时，新数据的引用数据类型属性值也会随之变化

案例介绍

import lombok.Data;

@Data
public class Student implements Cloneable {
    private String name;
    private int age;
    private Address address;

    @Override
    protected Object clone() throws CloneNotSupportedException {
        return super.clone();
    }
}

import lombok.Data;

@Data
public class Address {
    private String sheng;
    private String shi;
    private String qu;
}

import lombok.extern.slf4j.Slf4j;

@Slf4j
public class CopyDemo {
    public static void main(String[] args) throws CloneNotSupportedException {
        Address address = new Address();
        address.setSheng("湖北省");
        address.setShi("武汉市");
        address.setQu("洪山区");

        Student student = new Student();
        student.setName("张三");
        student.setAge(18);
        student.setAddress(address);

        //浅拷贝对象（需要对象实现Cloneable接口，重写clone方法）
        Student cloneStudent = (Student)student.clone();

        log.info("修改前_student={}",student);//修改前_student=Student(name=张三, age=18, address=Address(sheng=湖北省, shi=武汉市, qu=洪山区))
        log.info("修改前_cloneStudent={}",cloneStudent);//修改前_cloneStudent=Student(name=张三, age=18, address=Address(sheng=湖北省, shi=武汉市, qu=洪山区))
        address.setQu("武昌区");//修改引用数据类型的值
        log.info("修改后_student={}",student);//修改后_student=Student(name=张三, age=18, address=Address(sheng=湖北省, shi=武汉市, qu=武昌区))
        log.info("修改后_cloneStudent={}",cloneStudent);//修改后_cloneStudent=Student(name=张三, age=18, address=Address(sheng=湖北省, shi=武汉市, qu=武昌区))
    }
}

深拷贝

定义

创建一个新的对象，基础数据类型属性复制值，引用数据类型属性会创建一个新的对象，引用新的地址

特点

当修改原数据的引用数据类型属性的值时，新数据的引用数据类型属性值不会变化

案例介绍

import lombok.Data;

import java.io.Serializable;

@Data
public class Student implements Serializable {
    private String name;
    private int age;
    private Address address;
}

import lombok.Data;

import java.io.Serializable;

@Data
public class Address implements Serializable {
    private String sheng;
    private String shi;
    private String qu;
}

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.SerializationUtils;

@Slf4j
public class CopyDemo {
    public static void main(String[] args) throws CloneNotSupportedException {
        Address address = new Address();
        address.setSheng("湖北省");
        address.setShi("武汉市");
        address.setQu("洪山区");

        Student student = new Student();
        student.setName("张三");
        student.setAge(18);
        student.setAddress(address);

        byte[] serialize = SerializationUtils.serialize(student);//序列化
        Student cloneStudent = (Student)SerializationUtils.deserialize(serialize);//反序列化

        log.info("修改前_student={}",student);//修改前_student=Student(name=张三, age=18, address=Address(sheng=湖北省, shi=武汉市, qu=洪山区))
        log.info("修改前_cloneStudent={}",cloneStudent);//修改前_cloneStudent=Student(name=张三, age=18, address=Address(sheng=湖北省, shi=武汉市, qu=洪山区))
        address.setQu("武昌区");//修改引用数据类型的值
        log.info("修改后_student={}",student);//修改后_student=Student(name=张三, age=18, address=Address(sheng=湖北省, shi=武汉市, qu=武昌区))
        log.info("修改后_cloneStudent={}",cloneStudent);//修改后_cloneStudent=Student(name=张三, age=18, address=Address(sheng=湖北省, shi=武汉市, qu=洪山区))
    }
}

BeanUtil.copyProperties属于浅拷贝