Java中的對(duì)象拷貝分為淺拷貝和深拷貝兩種方式。在進(jìn)行對(duì)象拷貝的時(shí)候，需要注意對(duì)象內(nèi)部存在引用數(shù)據(jù)類型的情況，因?yàn)閱渭兊目截愔粫?huì)復(fù)制引用地址，而不會(huì)創(chuàng)建一個(gè)新的對(duì)象。下面我們具體介紹一下Java中如何進(jìn)行淺拷貝和深拷貝。

1. 淺拷貝

public class Person implements Cloneable {
private String name;
private int age;
private Address addr;
// 構(gòu)造方法
public Person(String name, int age, Address addr) {
this.name = name;
this.age = age;
this.addr = addr;
}
// 克隆方法，實(shí)現(xiàn)淺拷貝
public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException e) {
e.printStackTrace();
}
return null;
}
}
public class Address {
private String city;
// 構(gòu)造方法
public Address(String city) {
this.city = city;
}
}
public static void main(String[] args) {
Address addr = new Address("Beijing");
Person p1 = new Person("Tom", 20, addr);
Person p2 = (Person) p1.clone(); // 淺拷貝
System.out.println(p1.addr == p2.addr); // true
}

在上述代碼中，我們定義了一個(gè)Person類和Address類。Person類中包含了一個(gè)Address類的引用addr，實(shí)現(xiàn)了Cloneable接口并重寫了clone()方法，實(shí)現(xiàn)了淺拷貝。在執(zhí)行p2 = (Person) p1.clone()時(shí)，p2對(duì)象中的addr成員變量會(huì)復(fù)制p1對(duì)象中的addr成員變量的引用地址，兩者指向的是同一個(gè)對(duì)象。

2. 深拷貝

public class Person implements Serializable {
private String name;
private int age;
private Address addr;
// 構(gòu)造方法
public Person(String name, int age, Address addr) {
this.name = name;
this.age = age;
this.addr = addr;
}
// 克隆方法，實(shí)現(xiàn)深拷貝
public Object deepClone() throws IOException, ClassNotFoundException {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(baos);
oos.writeObject(this);
ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
ObjectInputStream ois = new ObjectInputStream(bais);
return ois.readObject();
}
}
public class Address implements Serializable{
private String city;
// 構(gòu)造方法
public Address(String city) {
this.city = city;
}
}
public static void main(String[] args) throws IOException, ClassNotFoundException {
Address addr = new Address("Beijing");
Person p1 = new Person("Tom", 20, addr);
Person p2 = (Person) p1.deepClone(); // 深拷貝
System.out.println(p1.addr == p2.addr); // false
}

在上述代碼中，我們實(shí)現(xiàn)了Serializable接口，通過(guò)ObjectOutputStream和ObjectInputStream實(shí)現(xiàn)了深拷貝。在執(zhí)行p2 = (Person) p1.deepClone()時(shí)，p2對(duì)象中的addr成員變量會(huì)創(chuàng)建一個(gè)新的Address對(duì)象，從而達(dá)到深拷貝的目的。