Java对象克隆：从浅到深的奥秘

浅克隆与深克隆在Java中的应用及区别

核心概念

1. 浅克隆
   复制对象时仅克隆基本数据类型字段，引用类型字段共享原对象引用。实现方式：

class Person implements Cloneable {
    String name;
    Address address; // 引用类型字段
    
    @Override
    protected Object clone() throws CloneNotSupportedException {
        return super.clone(); // 默认浅克隆
    }
}

class Address {
    String city;
}

     2.深克隆
        完全独立复制对象及其关联对象：

class DeepPerson implements Cloneable {
    String name;
    Address address;

    @Override
    protected Object clone() throws CloneNotSupportedException {
        DeepPerson cloned = (DeepPerson) super.clone();
        cloned.address = new Address(); // 新建独立地址对象
        cloned.address.city = this.address.city;
        return cloned;
    }
}

应用场景对比

深度克隆进阶实现

1. 序列化方案（需实现Serializable接口）

import java.io.*;

class SerialCloneable implements Serializable {
    public Object deepClone() throws IOException, ClassNotFoundException {
        try (ByteArrayOutputStream bos = new ByteArrayOutputStream();
             ObjectOutputStream oos = new ObjectOutputStream(bos)) {
            oos.writeObject(this);
            
            try (ByteArrayInputStream bis = new ByteArrayInputStream(bos.toByteArray());
                 ObjectInputStream ois = new ObjectInputStream(bis)) {
                return ois.readObject();
            }
        }
    }
}

     2.嵌套对象克隆测试

public static void main(String[] args) throws Exception {
    // 浅克隆测试
    Address addr = new Address("Beijing");
    Person original = new Person("Alice", addr);
    Person cloned = (Person) original.clone();
    
    cloned.address.city = "Shanghai";
    System.out.println(original.address.city); // 输出"Shanghai"

    // 深克隆测试
    DeepPerson deepOriginal = new DeepPerson("Bob", new Address("Guangzhou"));
    DeepPerson deepClone = (DeepPerson) deepOriginal.clone();
    
    deepClone.address.city = "Shenzhen";
    System.out.println(deepOriginal.address.city); // 保持"Guangzhou"
}

核心差异总结

1. 对象关系拓扑：

   • 浅克隆：生成对象图与原对象共享叶节点
   • 深克隆：构建完全独立的对象树

2. 内存模型表现： 

      3.修改传播特性：

最佳实践建议

1. 优先考虑不可变对象设计
2. 复杂对象推荐使用深克隆框架（如Apache Commons Lang3的SerializationUtils）
3. 对于循环引用结构，需实现引用追踪机制
4. 注意克隆过程中静态字段的处理