javaclone拷贝的缺点_浅谈Java中实现深拷贝的两种方式—clone()Serialized

浅谈Java中实现深拷贝的两种方式—clone() & Serialized

发布于 2020-4-15|

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摘记: clone() 方法麻烦一些&＃xff0c;需要将所有涉及到的类实现声明式接口 Cloneable&＃xff0c;并覆盖Object类中的clone()方法&＃xff0c;并设置作用域为public(这是为了其他类可以使用到该clone方法)。序列化的方法简单&＃xff0c;需要将所有涉及到的类实现接口Serializable

&＃96;&＃96;&＃96;java

package b1ch06.clone ..

clone() 方法麻烦一些&＃xff0c;需要将所有涉及到的类实现声明式接口 Cloneable&＃xff0c;并覆盖Object类中的clone()方法&＃xff0c;并设置作用域为public(这是为了其他类可以使用到该clone方法)。序列化的方法简单&＃xff0c;需要将所有涉及到的类实现接口Serializable

&＃96;&＃96;&＃96;java

package b1ch06.clone;

import java.io.Serializable;

class Car implements Cloneable, Serializable {

private String band;

public Car(String band) {

this.band &＃61; band;

}

public String getBand() {

return band;

}

public void setBand(String band) {

this.band &＃61; band;

}

&＃64;Override

public Object clone() throws CloneNotSupportedException {

return super.clone();

}

}

&＃96;&＃96;&＃96;

&＃96;&＃96;&＃96;java

package b1ch06.clone;

import java.io.Serializable;

class Employee implements Cloneable, Serializable {

private String name;

private Car car;

public Employee(String name, Car car) {

this.name &＃61; name;

this.car &＃61; car;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name &＃61; name;

}

public Car getcar() {

return car;

}

public void setcar(Car car) {

this.car &＃61; car;

}

protected void test() {

System.out.println("test func");

}

&＃64;Override

public Object clone() throws CloneNotSupportedException {

Employee employee_cloned &＃61; (Employee) super.clone();

Car car_cloned &＃61; (Car) this.car.clone();

employee_cloned.setcar(car_cloned);

return employee_cloned;

}

}

&＃96;&＃96;&＃96;

&＃96;&＃96;&＃96;java

package b1ch06.clone;

import java.io.*;

public class SerializedClone {

&＃64;SuppressWarnings("unchecked")

public static T clone(T obj) {

T cloneObj &＃61; null;

try {

//写入字节流

ByteArrayOutputStream out &＃61; new ByteArrayOutputStream();

ObjectOutputStream obs &＃61; new ObjectOutputStream(out);

obs.writeObject(obj);

obs.close();

//分配内存&＃xff0c;写入原始对象&＃xff0c;生成新对象

ByteArrayInputStream ios &＃61; new ByteArrayInputStream(out.toByteArray());

ObjectInputStream ois &＃61; new ObjectInputStream(ios);

//返回生成的新对象

cloneObj &＃61; (T) ois.readObject();

ois.close();

} catch (Exception e) {

e.printStackTrace();

}

return cloneObj;

}

}

&＃96;&＃96;&＃96;

&＃96;&＃96;&＃96;java

package b1ch06.clone;

public class MyClone {

public static void main(String[] args) {

Car car &＃61; new Car("BMW");

Employee employee &＃61; new Employee("ANDY", car);

// 方法一&＃xff1a;覆盖所有涉及到的类的clone()方法

try {

Employee employee_cp &＃61; (Employee) employee.clone();

System.out.println("&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;");

System.out.println("original对象地址?:");

System.out.println(employee.toString());

System.out.println("copy对象地址?:");

System.out.println(employee_cp.toString());

System.out.println("前后两个对象指向同一地址?:");

System.out.println(employee_cp &＃61;&＃61; employee);

System.out.println("&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;");

System.out.println("original对象中car对象地址?:");

System.out.println(employee.getcar().toString());

System.out.println("copy对象中car对象地址?:");

System.out.println(employee_cp.getcar().toString());

System.out.println("前后两个car对象指向同一地址?:");

System.out.println(employee_cp &＃61;&＃61; employee);

} catch (CloneNotSupportedException e) {

e.printStackTrace();

}

// 方法二&＃xff1a;序列化实现深拷贝

Employee cloned_employee &＃61; SerializedClone.clone(employee);

System.out.println("&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;");

System.out.println("original对象地址?:");

System.out.println(employee.toString());

System.out.println("copy对象地址?:");

System.out.println(cloned_employee.toString());

System.out.println("前后两个对象指向同一地址?:");

System.out.println(cloned_employee &＃61;&＃61; employee);

System.out.println("&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;&＃61;");

System.out.println("original对象中car对象地址?:");

System.out.println(employee.getcar().toString());

System.out.println("copy对象中car对象地址?:");

System.out.println(cloned_employee.getcar().toString());

System.out.println("前后两个car对象指向同一地址?:");

System.out.println(cloned_employee &＃61;&＃61; employee);

}

}

&＃96;&＃96;&＃96;